Difference between revisions of "Unit PlatformRPi4"

Latest revision as of 05:08, 23 November 2022

While it might be possible to read the SD card during boot, check for a config.txt and parse it to determine the value of the enable_gic setting, to be fully functional this process would also need to parse the device tree information (if available) and check for a compatible GIC node. Even then that doesn't account for booting from USB, network or some other source and all of that would have to happen very early in the boot sequence to be usable.

To make matters worse there doesn't appear to be a documented way to detect which interrupt controller is enabled by reading a register value, the GIC even behaves as though it is working when the legacy controller is enabled but no interrupts are received.

To ensure a level of reliability regardless of what firmware and files and configuration settings are present Ultibo implements drivers for both the GIC and legacy interrupt controllers and includes a detection mechanism during early stage boot.

In simple terms the boot process configures the GIC and then installs an interrupt handler for the generic virtual timer and configures the timer to fire in 1ms before enabling interrupts. It then waits 2ms and disables interrupts, unconfigures the timer and deregisters the interrupt handler.

If the test worked the local variable GICAvailable will have been set by the handler to RPI4_GIC_AVAILABLE, if not the variable will remain at RPI4_GIC_UNAVAILABLE and the boot process will proceed to configure the legacy interrupt controller for use.

This is not an ideal mechanism and could potentially fail for other reasons (although it is carefully constructed to avoid many potential failures) but at present is the best option for allowing the boot process to succeed regardless of the firmware behavior.

Constants

RPi ARM physical to VC IO mapping RPI4_VCIO_*

`RPI4_VCIO_ALIAS = BCM2838_VCIO_ALIAS;`	The VCIO Alias (For ARM Physcial to VC IO translation)

RPi ARM physical to VC bus mapping RPI4_VCBUS_*

`RPI4_VCBUS_ALIAS = BCM2838_VCBUS_C_ALIAS;`	The currently selected VCBUS Alias (For ARM Physcial to VC Bus translation)

RPi secure world boot RPI4_SECURE_*

`RPI4_SECURE_BOOT = $00000001;`	If 1 then startup will attempt to switch back to secure world during boot process (Moved to ARMSecureBoot)
`RPI4_SECURE_BOOT_OFFSET = $000000D4;`	The address of the Secure Boot marker in the ARM boot stub
`RPI4_SECURE_BOOT_MARKER = $58495052;`	The Secure Boot marker (ASCII "RPIX")
`RPI4_SECURE_BOOT_CIRCLE = $53514946;`	The alternate Secure Boot marker (ASCII "FIQS") (As used by Circle)

RPi address of StartupHandler on reset RPI4_STARTUP_*

`RPI4_STARTUP_ADDRESS = $00008000;`	Obtain from linker

RPi page directory address and size RPI4_PAGE_DIRECTORY_*

`RPI4_PAGE_DIRECTORY_BASE = $00002000;`	Place the first level Page Directory after the interrupt vectors at 0x00001000 and before the first level Page Table at 0x00004000
`RPI4_PAGE_DIRECTORY_SIZE = SIZE_4K;`	ARM Cortex A72 first level Page Table is up to 4KB in size (512 64 bit (8 byte) entries)

RPi page table address and size RPI4_PAGE_TABLE_*

`RPI4_PAGE_TABLE_BASE = $00004000;`	Place the second level Page Table after the first level Page Directory at 0x00002000 and before the code start at 0x00008000
`RPI4_PAGE_TABLE_SIZE = SIZE_16K;`	ARM Cortex A72 second level Page Table is exactly 16KB in size (4 x 512 64 bit (8 byte) entries)

RPi vector table address and size RPI4_VECTOR_TABLE_*

`RPI4_VECTOR_TABLE_BASE = $00001000;`	Place the Interrupt Vector Table at 0x00001000 before the code start at 0x00008000
`RPI4_VECTOR_TABLE_SIZE = SIZE_64;`	The Interrupt Vector Table is exactly 64 bytes (16 32 bit (4 byte) entries)
`RPI4_VECTOR_TABLE_COUNT = 8;`	The Interrupt Vector Table contains 8 entries on an ARMv7 device

RPi CPU count RPI4_CPU_*

`RPI4_CPU_COUNT = BCM2838_CPU_COUNT;`
`RPI4_CPU_BOOT = CPU_ID_0;`
`RPI4_CPU_MASK = CPU_AFFINITY_0 or CPU_AFFINITY_1 or CPU_AFFINITY_2 or CPU_AFFINITY_3;`

RPi SWI RPI4_SWI_*

`RPI4_SWI_COUNT = 256;`	Number of available SWI entries

RPi interrupt RPI4_GIC_*

`RPI4_GIC_UNAVAILABLE = 0;`
`RPI4_GIC_AVAILABLE = 1;`

RPi core timer RPI4_CORE_TIMER_*

`RPI4_CORE_TIMER_PRESCALER = $25ED098;`	Divide the Crystal Clock by 54 to give a 1MHz Core Timer
`RPI4_CORE_TIMER_FREQUENCY = 1000000;`	The Core Timer frequency from the prescaler setting above
`RPI4_GENERIC_TIMER_FREQUENCY = 1000000;`	The ARM Generic Timer frequency from the prescaler setting above

`RPI4_CORE_TIMER_PRESCALER = $80000000;`	Divide the Crystal Clock by 1 to give a 54MHz Core Timer
`RPI4_CORE_TIMER_FREQUENCY = 54000000;`	The Core Timer frequency from the prescaler setting above
`RPI4_GENERIC_TIMER_FREQUENCY = 54000000;`	The ARM Generic Timer frequency from the prescaler setting above

RPi kernel image name RPI4_KERNEL_*

`RPI4_KERNEL_NAME = 'kernel7l.img';`
`RPI4_KERNEL_NAME = 'kernel8.img';`
`RPI4_KERNEL_CONFIG = 'config.txt';`
`RPI4_KERNEL_COMMAND = 'cmdline.txt';`
`RPI4_FIRMWARE_FILES = 'start4.elf,fixup4.dat,armstub32-rpi4.bin,armstub64-rpi4.bin';`
`RPI4_DTB_FILES = 'bcm2711-rpi-4-b.dtb,bcm2711-rpi-400.dtb,bcm2711-rpi-cm4.dtb,bcm2711-rpi-cm4s.dtb';`

RPi GPIO activity LED (GPIO Pin 42) RPI4_GPIO_ACTLED_*

`RPI4_GPIO_ACTLED_GPFSEL = BCM2838_GPFSEL4;`	GPFSEL register for ACT LED
`RPI4_GPIO_ACTLED_GPSET = BCM2838_GPSET1;`	GPSET register for ACT LED
`RPI4_GPIO_ACTLED_GPCLR = BCM2838_GPCLR1;`	GPCLR register for ACT LED
`RPI4_GPIO_ACTLED_GPPUD = BCM2838_GPPUD2;`	GPPUD register for ACT LED

`RPI4_GPIO_ACTLED_GPFSHIFT = 6;`	GPFSEL register shift for ACT LED
`RPI4_GPIO_ACTLED_GPFMASK = BCM2838_GPFSEL_MASK;`	GPFSEL register mask for ACT LED

`RPI4_GPIO_ACTLED_GPSHIFT = (42 - 32);`	GPSET/GPCLR register shift for ACT LED
`RPI4_GPIO_ACTLED_GPMASK = BCM2838_GPSET_MASK;`	GPSET/GPCLR register mask for ACT LED

`RPI4_GPIO_ACTLED_GPPUDSHIFT = 20;`	GPPUD register shift for ACT LED
`RPI4_GPIO_ACTLED_GPPUDMASK = BCM2838_GPPUD_MASK;`	GPPUD register mask for ACT LED

RPi mailbox timeout RPI4_MAILBOX_TIMEOUT_*

`RPI4_MAILBOX_TIMEOUT = 100;`	Default timeout to wait for mailbox calls to complete (Milliseconds)
`RPI4_MAILBOX_TIMEOUT_EX = 1000;`	Extended timeout to wait for mailbox calls to complete (Milliseconds)

RPi local mailbox RPI4_LOCAL_MAILBOX_*

`RPI4_LOCAL_MAILBOX_TIMEOUT = 100;`	Default timeout to wait for local mailbox calls to complete (Milliseconds)

RPi framebuffer RPI4_FRAMEBUFFER_*

`RPI4_FRAMEBUFFER_DESCRIPTION = 'BCM2838 Framebuffer';`

Type definitions

RPi4 framebuffer

PRPi4Framebuffer = ^TRPi4Framebuffer;

TRPi4Framebuffer = record

Framebuffer Properties
`Framebuffer:TFramebufferDevice;`
RPi4 Properties
`MultiDisplay:LongBool;`
`DisplayNum:LongWord;`
`DisplaySettings:TDisplaySettings;`

Public variables

RPi4 specific Ultibo variables

`RPi4Initialized:Boolean;`

`RPi4CNTVOFFLow:LongWord = 0;`	The low 32 bits of the Virtual Counter Offset register at boot time (CPU0 only) (Set by Startup) Must be initialized to remain in .data or else rewritten to zero with .bss

`RPi4CNTVOFFHigh:LongWord = 0;`	The high 32 bits of the Virtual Counter Offset register at boot time (CPU0 only) (Set by Startup) Must be initialized to remain in .data or else rewritten to zero with .bss

Timer register

`TimerRegisters:PBCM2838SystemTimerRegisters;`

Mailbox register

`Mailbox0Registers:PBCM2838Mailbox0Registers;`

`Mailbox1Registers:PBCM2838Mailbox1Registers;`

Interrupt device

`GICDevice:PGICDevice;`

`GICAvailable:LongWord = RPI4_GIC_AVAILABLE;`	The status of the GIC interrupt controller, determined during boot.

System call

`SystemCallEntries:array[0..RPI4_SWI_COUNT - 1] of TSystemCallEntry;`

Watchdog register

`WatchdogRegisters:PBCM2838PMWatchdogRegisters;`

ARM local register

`ARMLocalRegisters:PBCM2838ARMLocalRegisters;`

Virtual GPIO

`VirtualGPIOBuffer:TBCM2838VirtualGPIOBuffer;`

Function declarations

Initialization functions

procedure RPi4Init;

Description: To be documented

Note	None documented

procedure RPi4SecondarySwitch;

Description: Secondary CPU switch from HYP mode handler

Note	None documented

procedure RPi4SecondarySecure;

Description: Secondary CPU switch to secure mode handler

Note	None documented

procedure RPi4SecondaryHandler;

Description: Secondary CPU startup handler routine

Note	None documented

RPi4 platform functions

procedure RPi4SMPInit;

Description: To be documented

Note	None documented

procedure RPi4BoardInit;

Description: To be documented

Note	None documented

procedure RPi4MemoryInit;

Description: To be documented

Note	None documented

procedure RPi4ClockInit;

Description: To be documented

Note	None documented

procedure RPi4PowerInit;

Description: To be documented

Note	None documented

procedure RPi4MailboxInit;

Description: To be documented

Note	None documented

procedure RPi4InterruptInit;

Description: To be documented

Note	None documented

procedure RPi4PeripheralInit;

Description: To be documented

Note	None documented

procedure RPi4FramebufferInit;

Description: To be documented

Note	None documented

procedure RPi4PageTableInit;

Description: Initialize the Hardware Page Tables before enabling the MMU (LPAE version)

Note	None documented

procedure RPi4PageTableInitLegacy;

Description: Initialize the Hardware Page Tables before enabling the MMU (Legacy version)

Note	None documented

procedure RPi4PowerLEDEnable;

Description: To be documented

Note	None documented

procedure RPi4PowerLEDOn;

Description: To be documented

Note	None documented

procedure RPi4PowerLEDOff;

Description: To be documented

Note	None documented

procedure RPi4ActivityLEDEnable;

Description: To be documented

Note	None documented

procedure RPi4ActivityLEDOn;

Description: To be documented

Note	None documented

procedure RPi4ActivityLEDOff;

Description: To be documented

Note	None documented

function RPi4MailboxReceive(Mailbox,Channel:LongWord):LongWord;

Description: Receive from specified mailbox on specified channel

Note	Data = first 28 bits, Channel = last 4 bits

procedure RPi4MailboxSend(Mailbox,Channel,Data:LongWord);

Description: Send to specified mailbox on specified channel

Note	Data = first 28 bits, Channel = last 4 bits

function RPi4MailboxCall(Mailbox,Channel,Data:LongWord; var Response:LongWord):LongWord;

Description: Perform a transaction (Send/Receive) to specified mailbox on specified channel

Note	Data = first 28 bits, Channel = last 4 bits Data pointer must be 16 byte aligned to allow for the 4 bit channel number

function RPi4MailboxCallEx(Mailbox,Channel,Data:LongWord; var Response:LongWord; Timeout:LongWord):LongWord;

Description: Perform a transaction (Send/Receive) to specified mailbox on specified channel

Note	Data = first 28 bits, Channel = last 4 bits Data pointer must be 16 byte aligned to allow for the 4 bit channel number

function RPi4MailboxPropertyCall(Mailbox,Channel:LongWord; Data:Pointer; var Response:LongWord):LongWord;

Description: Perform a property tag transaction (Send/Receive) to specified mailbox on specified channel

Note	Data = first 28 bits, Channel = last 4 bits Data pointer must be 16 byte aligned to allow for the 4 bit channel number

function RPi4MailboxPropertyCallEx(Mailbox,Channel:LongWord; Data:Pointer; var Response:LongWord; Timeout:LongWord):LongWord;

Description: Perform a property tag transaction (Send/Receive) to specified mailbox on specified channel

Note	Data = first 28 bits, Channel = last 4 bits Data pointer must be 16 byte aligned to allow for the 4 bit channel number

function RPi4MailboxPropertyTag(Tag:LongWord; Data:Pointer; Size:LongWord):LongWord;

Description: Request a property tag (Get/Set) from the mailbox property channel

Data	Data does not need to include mailbox property channel header or footer. Data pointer does not need any specific alignment or caching attributes.
Size	Size must be a multiple of 4 bytes. Size must include the size of the request and response which use the same buffer.

function RPi4RequestExIRQ(CPUID,Number:LongWord; Handler:TInterruptHandler; HandlerEx:TInterruptExHandler; Parameter:Pointer):LongWord;

Description: Request registration of the supplied extended handler to the specified IRQ number

Note	None documented

function RPi4ReleaseExIRQ(CPUID,Number:LongWord; Handler:TInterruptHandler; HandlerEx:TInterruptExHandler; Parameter:Pointer):LongWord;

Description: Request deregistration of the supplied extended handler from the specified IRQ number

Note	None documented

function RPi4RequestExFIQ(CPUID,Number:LongWord; Handler:TInterruptHandler; HandlerEx:TInterruptExHandler; Parameter:Pointer):LongWord;

Description: Request registration of the supplied extended handler to the specified FIQ number

Note	None documented

function RPi4ReleaseExFIQ(CPUID,Number:LongWord; Handler:TInterruptHandler; HandlerEx:TInterruptExHandler; Parameter:Pointer):LongWord;

Description: Request deregistration of the supplied extended handler from the specified FIQ number

Note	None documented

function RPi4RequestIPI(CPUID,Number:LongWord; Handler:TIPIHandler; Parameter:Pointer):LongWord;

Description: Request registration of the supplied handler to the specified IPI number

Note	None documented

function RPi4ReleaseIPI(CPUID,Number:LongWord; Handler:TIPIHandler; Parameter:Pointer):LongWord;

Description: Request deregistration of the supplied handler from the specified IPI number

Note	None documented

function RPi4RegisterInterrupt(Number,Mask,Priority,Flags:LongWord; Handler:TSharedInterruptHandler; Parameter:Pointer):LongWord;

Description: Request registration of the supplied handler to the specified interrupt number (Where Applicable)

Number	The interrupt number to register the hanlder for
Mask	The mask of CPUs to register the handler for (eg CPU_MASK_0, CPU_MASK_1) (Where Applicable)
Priority	The priroty level of the interrupt to be registered (eg INTERRUPT_PRIORITY_MAXIMUM) (Where Applicable)
Flags	The flags to control the registration of the interrupt (eg INTERRUPT_FLAG_SHARED) (Where Applicable)
Handler	The shared interrupt handler to be called when the interrupt occurs
Parameter	A pointer to be passed to the handler when the interrupt occurs (Optional)
Return	ERROR_SUCCESS if the callback was scheduled successfully or another error code on failure

function RPi4DeregisterInterrupt(Number,Mask,Priority,Flags:LongWord; Handler:TSharedInterruptHandler; Parameter:Pointer):LongWord;

Description: Request deregistration of the supplied handler from the specified interrupt number (Where Applicable)

Number	The interrupt number to deregister the hanlder for
Mask	The mask of CPUs to deregister the handler for (eg CPU_MASK_0, CPU_MASK_1) (Where Applicable)
Priority	The priroty level of the interrupt to be deregistered (eg INTERRUPT_PRIORITY_MAXIMUM) (Where Applicable)
Flags	The flags to control the deregistration of the interrupt (eg INTERRUPT_FLAG_SHARED, INTERRUPT_FLAG_LOCAL, INTERRUPT_FLAG_FIQ) (Where Applicable)
Handler	The shared interrupt handler to be called when the interrupt occurs
Parameter	A pointer to be passed to the handler when the interrupt occurs (Optional)
Return	ERROR_SUCCESS if the callback was scheduled successfully or another error code on failure

function RPi4RegisterSystemCallEx(CPUID,Number:LongWord; Handler:TSystemCallHandler; HandlerEx:TSystemCallExHandler):LongWord;

Description: Request registration of the supplied extended handler to the specified System Call number

CPUID	The CPU ID to register the System Call against (or CPU_ID_ALL)
Number	The System Call number to be registered
Handler	The handler function to be registered
HandlerEx	The extended handler function to be registered
Note	Only one of Handler or HandlerEx can be specified

function RPi4DeregisterSystemCallEx(CPUID,Number:LongWord; Handler:TSystemCallHandler; HandlerEx:TSystemCallExHandler):LongWord;

Description: Request deregistration of the supplied extended handler from the specified System Call number

CPUID	The CPU ID to deregister the System Call from (or CPU_ID_ALL)
Number	The System Call number to be deregistered
Handler	The handler function to be deregistered
HandlerEx	The extended handler function to be deregistered
Note	Only one of Handler or HandlerEx can be specified

function RPi4GetInterruptEntry(Number,Instance:LongWord; var Interrupt:TInterruptEntry):LongWord;

Description: Get the interrupt entry for the specified interrupt number and instance

Note	None documented

function RPi4GetLocalInterruptEntry(CPUID,Number,Instance:LongWord; var Interrupt:TInterruptEntry):LongWord;

Description: Get the local interrupt entry for the specified interrupt number and instance

Note	None documented

function RPi4GetSoftwareInterruptEntry(CPUID,Number,Instance:LongWord; var Interrupt:TInterruptEntry):LongWord;

Description: Get the software interrupt entry for the specified interrupt number and instance

Note	None documented

function RPi4GetSystemCallEntry(Number:LongWord):TSystemCallEntry;

Description: Get the system call entry for the specified system call number

Note	None documented

function RPi4SystemRestart(Delay:LongWord):LongWord;

Description: To be documented

Note	None documented

function RPi4SystemShutdown(Delay:LongWord):LongWord;

Description: To be documented

Note	None documented

function RPi4SystemGetCommandLine:String;

Description: Get the Command Line from the Mailbox property tags channel

Note	None documented

function RPi4CPUGetMemory(var Address:PtrUInt; var Length:UInt64):LongWord;

Description: Get the CPU Memory from the Mailbox property tags channel

Note	None documented

function RPi4GPUGetState:LongWord;

Description: To be documented

Note	None documented

function RPi4GPUGetMemory(var Address:PtrUInt; var Length:UInt64):LongWord;

Description: Get the GPU Memory from the Mailbox property tags channel

Note	None documented

function RPi4BoardGetModel:LongWord;

Description: Get the Board Model from the Mailbox property tags channel

Note	None documented

function RPi4BoardGetSerial:Int64;

Description: Get the Board Serial from the Mailbox property tags channel

Note	None documented

function RPi4BoardGetRevision:LongWord;

Description: Get the Board Revision from the Mailbox property tags channel

Note	None documented

function RPi4BoardGetMACAddress:String;

Description: Get the Board MAC Address from the Mailbox property tags channel

Note	None documented

function RPi4ChipGetRevision:LongWord;

Description: Get the Chip Revision from the revision register

Note	None documented

function RPi4FirmwareGetRevision:LongWord;

Description: Get the Firmware Revision from the Mailbox property tags channel

Note	None documented

function RPi4FirmwareGetThrottled:LongWord;

Description: Get the Firmware Throttling state from the Mailbox property tags channel

Note	None documented

function RPi4PowerGetWait(PowerId:LongWord):LongWord;

Description: Get the Power Wait from the Mailbox property tags channel

Note	None documented

function RPi4PowerGetState(PowerId:LongWord):LongWord;

Description: Get the Power State from the Mailbox property tags channel

Note	None documented

function RPi4PowerSetState(PowerId,State:LongWord; Wait:Boolean):LongWord;

Description: Set the Power State in the Mailbox property tags channel

Note	Power Lock not required due to Mailbox Property Call serialization

function RPi4ClockGetCount:LongWord;

Description: Gets the current system clock count (32 least significant bits of total)

Note	On the Raspberry Pi this comes from the System Timer free running counter which runs at 1MHz and therefore overflows every 4295 seconds

function RPi4ClockGetTotal:Int64;

Description: Gets the total system clock count

Note	On the Raspberry Pi this comes from the System Timer free running counter which runs at 1MHz, the clock interrupt also uses this timer to increment the clock every second and therefore keep time.

function RPi4ClockGetRate(ClockId:LongWord):LongWord;

Description: Get the Clock Rate from the Mailbox property tags channel

Note	None documented

function RPi4ClockSetRate(ClockId,Rate:LongWord; Turbo:Boolean):LongWord;

Description: Set the Clock Rate in the Mailbox property tags channel

Note	None documented

function RPi4ClockGetState(ClockId:LongWord):LongWord;

Description: Get the Clock State from the Mailbox property tags channel

Note	None documented

function RPi4ClockSetState(ClockId,State:LongWord):LongWord;

Description: Set the Clock State in the Mailbox property tags channel

Note	None documented

function RPi4ClockGetMinRate(ClockId:LongWord):LongWord;

Description: Get the Clock Min Rate from the Mailbox property tags channel

Note	None documented

function RPi4ClockGetMaxRate(ClockId:LongWord):LongWord;

Description: Get the Clock Max Rate from the Mailbox property tags channel

Note	None documented

function RPi4TurboGetState(TurboId:LongWord):LongWord;

Description: Get the Turbo State from the Mailbox property tags channel

Note	None documented

function RPi4TurboSetState(TurboId,State:LongWord):LongWord;

Description: Set the Turbo State in the Mailbox property tags channel

Note	None documented

function RPi4VoltageGetValue(VoltageId:LongWord):LongWord;

Description: Get the Voltage Value from the Mailbox property tags channel

Note	None documented

function RPi4VoltageSetValue(VoltageId,Value:LongWord):LongWord;

Description: Set the Voltage Value in the Mailbox property tags channel

Note	None documented

function RPi4VoltageGetMinValue(VoltageId:LongWord):LongWord;

Description: Get the Voltage Min Value from the Mailbox property tags channel

Note	None documented

function RPi4VoltageGetMaxValue(VoltageId:LongWord):LongWord;

Description: Get the Voltage Max Value from the Mailbox property tags channel

Note	None documented

function RPi4TemperatureGetCurrent(TemperatureId:LongWord):LongWord;

Description: Get the Temperature Current from the Mailbox property tags channel

Note	None documented

function RPi4TemperatureGetMaximum(TemperatureId:LongWord):LongWord;

Description: Get the Temperature Maximum Model from the Mailbox property tags channel

Note	None documented

function RPi4GPUMemoryAllocate(Length,Alignment,Flags:LongWord):THandle;

Description: Allocate GPU Memory from the Mailbox property tags channel

Note	None documented

function RPi4GPUMemoryRelease(Handle:THandle):LongWord;

Description: Release GPU Memory from the Mailbox property tags channel

Note	None documented

function RPi4GPUMemoryLock(Handle:THandle):LongWord;

Description: Lock GPU Memory from the Mailbox property tags channel

Note	None documented

function RPi4GPUMemoryUnlock(Handle:THandle):LongWord;

Description: Unlock GPU Memory from the Mailbox property tags channel

Note	None documented

function RPi4GPUExecuteCode(Address:Pointer; R0,R1,R2,R3,R4,R5:LongWord):LongWord;

Description: Execute GPU Code from the Mailbox property tags channel

Note	None documented

function RPi4DispmanxHandleGet(Resource:THandle):THandle;

Description: Get Dispmanx Memory Handle from the Mailbox property tags channel

Note	None documented

function RPi4EDIDBlockGet(Block:LongWord; Buffer:Pointer; Length:LongWord):LongWord;

Description: Get EDID Block from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferAllocate(Alignment:LongWord; var Address,Length:LongWord):LongWord;

Description: Allocate Framebuffer from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferRelease:LongWord;

Description: Release Framebuffer from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetState(State:LongWord):LongWord;

Description: Set Framebuffer State (Blank Screen) from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetDimensions(var Width,Height,Top,Bottom,Left,Right:LongWord):LongWord;

Description: Get Framebuffer Dimensions from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetPhysical(var Width,Height:LongWord):LongWord;

Description: Get Framebuffer Physical size from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetPhysical(var Width,Height:LongWord):LongWord;

Description: Set Framebuffer Physical size from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferTestPhysical(var Width,Height:LongWord):LongWord;

Description: Test Framebuffer Physical size from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetVirtual(var Width,Height:LongWord):LongWord;

Description: Get Framebuffer Virtual size from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetVirtual(var Width,Height:LongWord):LongWord;

Description: Set Framebuffer Virtual size from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferTestVirtual(var Width,Height:LongWord):LongWord;

Description: Test Framebuffer Virtual size from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetDepth(var Depth:LongWord):LongWord;

Description: Get Framebuffer Depth (Bits per pixel) from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetDepth(var Depth:LongWord):LongWord;

Description: Set Framebuffer Depth (Bits per pixel) from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferTestDepth(var Depth:LongWord):LongWord;

Description: Test Framebuffer Depth (Bits per pixel) from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetPixelOrder(var Order:LongWord):LongWord;

Description: Get Framebuffer Pixel Order (RGB) from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetPixelOrder(var Order:LongWord):LongWord;

Description: Set Framebuffer Pixel Order (RGB) from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferTestPixelOrder(var Order:LongWord):LongWord;

Description: Test Framebuffer Pixel Order (RGB) from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetAlphaMode(var Mode:LongWord):LongWord;

Description: Get Framebuffer Alpha Mode from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetAlphaMode(var Mode:LongWord):LongWord;

Description: Set Framebuffer Alpha Mode from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferTestAlphaMode(var Mode:LongWord):LongWord;

Description: Test Framebuffer Alpha Mode from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetPitch:LongWord;

Description: Get Framebuffer Pitch (Bytes per line) from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetOffset(var X,Y:LongWord):LongWord;

Description: Get Framebuffer Virtual Offset from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetOffset(var X,Y:LongWord):LongWord;

Description: Set Framebuffer Virtual Offset from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferTestOffset(var X,Y:LongWord):LongWord;

Description: Test Framebuffer Virtual Offset from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetOverscan(var Top,Bottom,Left,Right:LongWord):LongWord;

Description: Get Framebuffer Overscan from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetOverscan(var Top,Bottom,Left,Right:LongWord):LongWord;

Description: Set Framebuffer Overscan from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferTestOverscan(var Top,Bottom,Left,Right:LongWord):LongWord;

Description: Test Framebuffer Overscan from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetPalette(Buffer:Pointer;Length:LongWord):LongWord;

Description: Get Framebuffer Palette from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetPalette(Start,Count:LongWord; Buffer:Pointer; Length:LongWord):LongWord;

Description: Set Framebuffer Palette from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferTestPalette(Start,Count:LongWord; Buffer:Pointer; Length:LongWord):LongWord;

Description: Test Framebuffer Palette from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetLayer(var Layer:LongInt):LongWord;

Description: Get Framebuffer Layer from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetLayer(var Layer:LongInt):LongWord;

Description: Set Framebuffer Layer from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferTestLayer(var Layer:LongInt):LongWord;

Description: Test Framebuffer Layer from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferTestVsync:LongWord;

Description: Test Framebuffer Vertical Sync from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetVsync:LongWord;

Description: Set Framebuffer Vertical Sync from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetBacklight(Brightness:LongWord):LongWord;

Description: Set Framebuffer Backlight Brightness from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetNumDisplays(var NumDisplays:LongWord):LongWord;

Description: Get the number of displays from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetDisplayId(DisplayNum:LongWord):LongWord;

Description: Get the display id for the specified display number from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferSetDisplayNum(DisplayNum:LongWord):LongWord;

Description: Get the display number that all framebuffer requests will refer to using the Mailbox property tags channel

Note	None documented

function RPi4FramebufferGetDisplaySettings(DisplayNum:LongWord; var DisplaySettings:TDisplaySettings):LongWord;

Description: Get the display settings for the specified display number from the Mailbox property tags channel

Note	None documented

function RPi4FramebufferDisplayIdToName(DisplayId:LongWord):String;

Description: Get the name for the specified display id

Note	None documented

function RPi4TouchGetBuffer(var Address:PtrUInt):LongWord;

Description: Get the Touchscreen buffer from the Mailbox property tags channel

Note	On current firmware versions calling TouchGetBuffer will allocate a buffer from GPU memory and render subsequent calls to TouchSetBuffer ineffective. After an initial call to TouchSetBuffer calls to TouchGetBuffer will always return the CPU allocated buffer.

function RPi4TouchSetBuffer(Address:PtrUInt):LongWord;

Description: Set the Touchscreen buffer in the Mailbox property tags channel

Note	None documented

function RPi4VirtualGPIOGetBuffer(var Address:PtrUInt):LongWord;

Description: Get the Virtual GPIO buffer from the Mailbox property tags channel

Note	None documented

function RPi4VirtualGPIOSetBuffer(Address:PtrUInt):LongWord;

Description: Set the Virtual GPIO buffer in the Mailbox property tags channel

Note	None documented

function RPi4CursorSetDefault:LongWord;

Description: Set Cursor Default (Pixels) from the Mailbox property tags channel

Note	None documented

function RPi4CursorSetInfo(Width,Height,HotspotX,HotspotY:LongWord; Pixels:Pointer; Length:LongWord):LongWord;

Description: Set Cursor Info (Pixels) from the Mailbox property tags channel

Note	None documented

function RPi4CursorSetState(Enabled:Boolean; X,Y:LongWord; Relative:Boolean):LongWord;

Description: Set Cursor State (Enable, X, Y) from the Mailbox property tags channel

Relative	X, Y is relative to Display (Virtual) not Framebuffer (Physical)

function RPi4DMAGetChannels:LongWord;

Description: Get the available DMA Channels from the Mailbox property tags channel

Note	None documented

function RPi4VirtualGPIOInputGet(Pin:LongWord):LongWord;

Description: To be documented

Note	None documented

function RPi4VirtualGPIOOutputSet(Pin,Level:LongWord):LongWord;

Description: To be documented

Note	None documented

function RPi4VirtualGPIOFunctionSelect(Pin,Mode:LongWord):LongWord;

Description: To be documented

Note	None documented

RPi4 thread functions

procedure RPi4SchedulerInit;

Description: Initialize the scheduler interrupt on the boot CPU

Note	None documented

procedure RPi4SchedulerStart(CPUID:LongWord);

Description: Initialize the scheduler interrupt on the specified secondary CPU

Note	None documented

procedure RPi4SecondaryBoot(CPUID:LongWord);

Description: To be documented

Note	None documented

RPi4 SWI functions

function RPi4DispatchSWI(CPUID:LongWord; Thread:TThreadHandle; Request:PSystemCallRequest):TThreadHandle;

Description: Process an SWI request

Note	Called by ARMv7/8SoftwareInterruptHandler in PlatformARMv7/8 A DataMemoryBarrier is executed before and after calling this function.

RPi4 clock functions

procedure RPi4ClockInterrupt(Parameter:Pointer);

Description: Interrupt handler function for the clock interrupt

Note	This schedules another clock interrupt to occur CLOCK_CYCLES_PER_TICK in the future, then updates ClockTicks and ClockSeconds and checks for timers to trigger.

procedure RPi4ClockUpdate(Cycles:LongWord; var Last:LongWord);

Description: Setup a clock interrupt to trigger after the specified number of clock cycles

Cycles	Number of cycles after which the timer interrupt is to be triggered
Note	This refers to native clock cycles as specified by CLOCK_FREQUENCY

RPi4 scheduler functions

function RPi4SchedulerInterrupt(CPUID:LongWord; Thread:TThreadHandle; Parameter:Pointer):TThreadHandle;

Description: Interrupt handler function for the scheduler interrupt

Note	This schedules another scheduler interrupt to occur SCHEDULER_CLOCKS_PER_INTERRUPT in the future, then checks for threads to wakeup or timeout and the next thread to schedule.

procedure RPi4SchedulerUpdate(Cycles:LongWord; var Last:LongWord);

Description: Setup a scheduler interrupt to trigger after the specified number of clock cycles

Cycles	Number of cycles after which the scheduler interrupt is to be triggered
Note	This refers to native clock cycles as specified by RPI4_GENERIC_TIMER_FREQUENCY

procedure RPi4SchedulerSystemCall(Request:PSystemCallRequest);

Description: System Call handler for the scheduler

Note	This is registered to receive requests for the SYSTEM_CALL_CONTEXT_SWITCH and will perform a context switch from within an SWI

RPi4 framebuffer functions

function RPi4FramebufferDeviceAllocate(Framebuffer:PFramebufferDevice; Properties:PFramebufferProperties):LongWord;

Description: Allocate a framebuffer using the Mailbox Property Tags

Note	None documented

function RPi4FramebufferDeviceAllocateAlt(Framebuffer:PFramebufferDevice; Properties:PFramebufferProperties):LongWord;

Description: Allocate a framebuffer using a simple Mailbox Call

Note	None documented

function RPi4FramebufferDeviceRelease(Framebuffer:PFramebufferDevice):LongWord;

Description: To be documented

Note	None documented

function RPi4FramebufferDeviceBlank(Framebuffer:PFramebufferDevice; Blank:Boolean):LongWord;

Description: To be documented

Note	None documented

function RPi4FramebufferDeviceCommit(Framebuffer:PFramebufferDevice; Address:PtrUInt; Size,Flags:LongWord):LongWord;

Description: To be documented

Note	None documented

function RPi4FramebufferDeviceSetBacklight(Framebuffer:PFramebufferDevice; Brightness:LongWord):LongWord;

Description: To be documented

Note	None documented

RPi4 helper functions

procedure RPi4Wait;

Description: To be documented

Note	None documented

procedure RPi4LongWait;

Description: To be documented

Note	None documented

procedure RPi4ShortWait;

Description: To be documented

Note	None documented

procedure RPi4SlowBlink;

Description: To be documented

Note	None documented

procedure RPi4FastBlink;

Description: To be documented

Note	None documented

procedure RPi4BootBlink;

Description: Blink the Activity LED without dependency on any other RTL setup

Note	None documented

procedure RPi4BootOutput(Value:LongWord);

Description: Output characters to UART0 without dependency on any other RTL setup

Note	This function is primarily intended for testing QEMU boot because it doesn't initialize the UART and won't work on real hardware. Based on hexstrings() function by dwelch67 (https://github.com/dwelch67)

procedure RPi4BootConsoleStart;

Description: To be documented

Note	None documented

procedure RPi4BootConsoleWrite(const Value:String);

Description: To be documented

Note	None documented

procedure RPi4BootConsoleWriteEx(const Value:String; X,Y:LongWord);

Description: To be documented

Note	None documented

function RPi4BootConsoleGetX:LongWord;

Description: To be documented

Note	None documented

function RPi4BootConsoleGetY:LongWord;

Description: To be documented

Note	None documented

function RPi4ConvertPowerIdRequest(PowerId:LongWord):LongWord;

Description: Convert Ultibo Power Id to BCM2838 Power Id

Note	None documented

function RPi4ConvertPowerStateRequest(PowerState:LongWord):LongWord;

Description: Convert Ultibo Power State to BCM2838 Power State

Note	None documented

function RPi4ConvertPowerStateResponse(PowerState:LongWord):LongWord;

Description: Convert BCM2838 Power State to Ultibo Power State

Note	None documented

function RPi4ConvertClockIdRequest(ClockId:LongWord):LongWord;

Description: Convert Ultibo Clock Id to BCM2838 Clock Id

Note	None documented

function RPi4ConvertClockStateRequest(ClockState:LongWord):LongWord;

Description: Convert Ultibo Clock State to BCM2838 Clock State

Note	None documented

function RPi4ConvertClockStateResponse(ClockState:LongWord):LongWord;

Description: Convert BCM2838 Clock State to Ultibo Clock State

Note	None documented

function RPi4ConvertVoltageIdRequest(VoltageId:LongWord):LongWord;

Description: Convert Ultibo Voltage Id to BCM2838 Voltage Id

Note	None documented

function RPi4ConvertTemperatureIdRequest(TemperatureId:LongWord):LongWord;

Description: Convert Ultibo Temperature Id to BCM2838 Temperature Id

Note	None documented

Return to Unit Reference

Difference between revisions of "Unit PlatformRPi4"

Latest revision as of 05:08, 23 November 2022

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@@ Line 5: / Line 5: @@
 ----
-'''Ultibo Platform interface unit for Raspberry Pi 4'''
+'''Ultibo Platform Interface unit for Raspberry Pi 4'''
-This unit extends the Platform ARMv7 unit to provide support for implementations using the Large Physical Address Extensions (LPAE) to access greater than 4GB of memory in 32-bit environments.
+Note: The RPi4B has the Activity LED connected to GPIO Pin 42 (Power LED is only accessible via the GPIO expander driver)
-The LPAE defines a new page table descriptor format along with new memory region attributes and memory attribute indirection registers (MAIR0/1) as well as extending the TTBR0, TTBR1 and TTBCR registers with additional information.
+'''Detecting the GIC or legacy interrupt controller'''
+The Raspberry Pi 4 contains a new GIC interrupt controller which includes modern features like the ability to service interrupts on all available cores, a full set of software generated processor to processor interrupts and complete FIQ handling for all interrupt sources.
+The Pi 4 also retains and expands the legacy interrupt controller used on earlier Pi models with support for routing interrupts to any core and FIQ handling for all interrupt sources.
+The documentation at https://www.raspberrypi.org/documentation/configuration/config-txt/boot.md states that the setting enable_gic=0 or 1 can be used to select between the legacy and GIC interrupt controllers and that the GIC (enable_gic=1) is the default.
+Testing however shows this is not completely correct, if no config.txt file exists and no device tree DTB files are present then the current firmware appears to enable the legacy interrupt controller by default.
+If device tree DTB files containing a compatible GIC node are available on the SD card during boot the firmware will enable the GIC, this appears to happen regardless of the setting in config.txt and a value of enable_gic=0 will be ignored in favour of the device tree setting.
+If the legacy interrupt controller is enabled and Ultibo configures the GIC controller during boot it will receive no interrupts and appear to hang (four color screen).
+While it might be possible to read the SD card during boot, check for a config.txt and parse it to determine the value of the enable_gic setting, to be fully functional this process would also need to parse the device tree information (if available) and check for a compatible GIC node. Even then that doesn't account for booting from USB, network or some other source and all of that would have to happen very early in the boot sequence to be usable.
+To make matters worse there doesn't appear to be a documented way to detect which interrupt controller is enabled by reading a register value, the GIC even behaves as though it is working when the legacy controller is enabled but no interrupts are received.
+To ensure a level of reliability regardless of what firmware and files and configuration settings are present Ultibo implements drivers for both the GIC and legacy interrupt controllers and includes a detection mechanism during early stage boot.
+In simple terms the boot process configures the GIC and then installs an interrupt handler for the generic virtual timer and configures the timer to fire in 1ms before enabling interrupts. It then waits 2ms and disables interrupts, unconfigures the timer and deregisters the interrupt handler.
+If the test worked the local variable GICAvailable will have been set by the handler to RPI4_GIC_AVAILABLE, if not the variable will remain at RPI4_GIC_UNAVAILABLE and the boot process will proceed to configure the legacy interrupt controller for use.
-The LPAE extensions allow addressing of up to 40 bits of physical address space (1TB) by mapping it into the 32-bit virtual address space.
+This is not an ideal mechanism and could potentially fail for other reasons (although it is carefully constructed to avoid many potential failures) but at present is the best option for allowing the boot process to succeed regardless of the firmware behavior.
-For 64-bit environments the Platform ARMv8 unit provides the equivalent functionality as LPAE is not required and the processor can address up to 48 bits of address space directly. All functionality not directly related to LPAE is provided from the Platform ARMv7 unit.
 === Constants ===
 ----
-''To be documented''
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi ARM physical to VC IO mapping''' <code> RPI4_VCIO_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_VCIO_ALIAS = BCM2838_VCIO_ALIAS;</code>
+| style="width: 50%;"|The VCIO Alias (For ARM Physcial to VC IO translation)
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi ARM physical to VC bus mapping''' <code> RPI4_VCBUS_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_VCBUS_ALIAS = BCM2838_VCBUS_C_ALIAS;</code>
+| style="width: 50%;"|The currently selected VCBUS Alias (For ARM Physcial to VC Bus translation)
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi secure world boot''' <code> RPI4_SECURE_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_SECURE_BOOT = $00000001;</code>
+| style="width: 50%;"|If 1 then startup will attempt to switch back to secure world during boot process (Moved to ARMSecureBoot)
+|-
+| <code>RPI4_SECURE_BOOT_OFFSET = $000000D4;</code>
+| The address of the Secure Boot marker in the ARM boot stub
+|-
+| <code>RPI4_SECURE_BOOT_MARKER = $58495052;</code>
+| The Secure Boot marker (ASCII "RPIX")
+|-
+| <code>RPI4_SECURE_BOOT_CIRCLE = $53514946;</code>
+| The alternate Secure Boot marker (ASCII "FIQS") (As used by Circle)
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi address of StartupHandler on reset''' <code> RPI4_STARTUP_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_STARTUP_ADDRESS = $00008000;</code>
+| style="width: 50%;"|Obtain from linker
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi page directory address and size''' <code> RPI4_PAGE_DIRECTORY_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_PAGE_DIRECTORY_BASE = $00002000;</code>
+| style="width: 50%;"|Place the first level Page Directory after the interrupt vectors at 0x00001000 and before the first level Page Table at 0x00004000
+|-
+| <code>RPI4_PAGE_DIRECTORY_SIZE = SIZE_4K;</code>
+| ARM Cortex A72 first level Page Table is up to 4KB in size (512 64 bit (8 byte) entries)
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi page table address and size''' <code> RPI4_PAGE_TABLE_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_PAGE_TABLE_BASE = $00004000;</code>
+| style="width: 50%;"|Place the second level Page Table after the first level Page Directory at 0x00002000 and before the code start at 0x00008000
+|-
+| <code>RPI4_PAGE_TABLE_SIZE = SIZE_16K;</code>
+| ARM Cortex A72 second level Page Table is exactly 16KB in size (4 x 512 64 bit (8 byte) entries)
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi vector table address and size''' <code> RPI4_VECTOR_TABLE_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_VECTOR_TABLE_BASE = $00001000;</code>
+| style="width: 50%;"|Place the Interrupt Vector Table at 0x00001000 before the code start at 0x00008000
+|-
+| <code>RPI4_VECTOR_TABLE_SIZE = SIZE_64;</code>
+| The Interrupt Vector Table is exactly 64 bytes (16 32 bit (4 byte) entries)
+|-
+| <code>RPI4_VECTOR_TABLE_COUNT = 8;</code>
+| The Interrupt Vector Table contains 8 entries on an ARMv7 device
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi CPU count''' <code> RPI4_CPU_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_CPU_COUNT = BCM2838_CPU_COUNT;</code>
+| style="width: 50%;"|&nbsp;
+|-
+| <code>RPI4_CPU_BOOT = CPU_ID_0;</code>
+| &nbsp;
+|-
+|colspan="2"|<code>RPI4_CPU_MASK = CPU_AFFINITY_0 or CPU_AFFINITY_1 or CPU_AFFINITY_2 or CPU_AFFINITY_3;</code>
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi SWI''' <code> RPI4_SWI_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_SWI_COUNT = 256;</code>
+| style="width: 50%;"|Number of available SWI entries
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi interrupt''' <code> RPI4_GIC_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_GIC_UNAVAILABLE = 0;</code>
+| style="width: 50%;"|&nbsp;
+|-
+| <code>RPI4_GIC_AVAILABLE = 1;</code>
+| &nbsp;
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi core timer''' <code> RPI4_CORE_TIMER_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_CORE_TIMER_PRESCALER = $25ED098;</code>
+| style="width: 50%;"|Divide the Crystal Clock by 54 to give a 1MHz Core Timer
+|-
+| <code>RPI4_CORE_TIMER_FREQUENCY = 1000000;</code>
+| The Core Timer frequency from the prescaler setting above
+|-
+| <code>RPI4_GENERIC_TIMER_FREQUENCY = 1000000;</code>
+| The ARM Generic Timer frequency from the prescaler setting above
+|-
+|colspan="2"|&nbsp;
+|-
+| <code>RPI4_CORE_TIMER_PRESCALER = $80000000;</code>
+| Divide the Crystal Clock by 1 to give a 54MHz Core Timer
+|-
+| <code>RPI4_CORE_TIMER_FREQUENCY = 54000000;</code>
+| The Core Timer frequency from the prescaler setting above
+|-
+| <code>RPI4_GENERIC_TIMER_FREQUENCY = 54000000;</code>
+| The ARM Generic Timer frequency from the prescaler setting above
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi kernel image name''' <code> RPI4_KERNEL_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_KERNEL_NAME = 'kernel7l.img';</code>
+| style="width: 50%;"|&nbsp;
+|-
+| <code>RPI4_KERNEL_NAME = 'kernel8.img';</code>
+| &nbsp;
+|-
+| <code>RPI4_KERNEL_CONFIG = 'config.txt';</code>
+| &nbsp;
+|-
+| <code>RPI4_KERNEL_COMMAND = 'cmdline.txt';</code>
+| &nbsp;
+|-
+|colspan="2"|<code>RPI4_FIRMWARE_FILES = 'start4.elf,fixup4.dat,armstub32-rpi4.bin,armstub64-rpi4.bin';</code>
+|-
+|colspan="2"|<code>RPI4_DTB_FILES = 'bcm2711-rpi-4-b.dtb,bcm2711-rpi-400.dtb,bcm2711-rpi-cm4.dtb,bcm2711-rpi-cm4s.dtb';</code>
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi GPIO activity LED (GPIO Pin 42)''' <code> RPI4_GPIO_ACTLED_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_GPIO_ACTLED_GPFSEL = BCM2838_GPFSEL4;</code>
+| style="width: 50%;"|GPFSEL register for ACT LED
+|-
+| <code>RPI4_GPIO_ACTLED_GPSET = BCM2838_GPSET1;</code>
+| GPSET register for ACT LED
+|-
+| <code>RPI4_GPIO_ACTLED_GPCLR = BCM2838_GPCLR1;</code>
+| GPCLR register for ACT LED
+|-
+| <code>RPI4_GPIO_ACTLED_GPPUD = BCM2838_GPPUD2;</code>
+| GPPUD register for ACT LED
+|-
+|colspan="2"|&nbsp;
+|-
+| <code>RPI4_GPIO_ACTLED_GPFSHIFT = 6;</code>
+| GPFSEL register shift for ACT LED
+|-
+| <code>RPI4_GPIO_ACTLED_GPFMASK = BCM2838_GPFSEL_MASK;</code>
+| GPFSEL register mask for ACT LED
+|-
+|colspan="2"|&nbsp;
+|-
+| <code>RPI4_GPIO_ACTLED_GPSHIFT = (42 - 32);</code>
+| GPSET/GPCLR register shift for ACT LED
+|-
+| <code>RPI4_GPIO_ACTLED_GPMASK = BCM2838_GPSET_MASK;</code>
+| GPSET/GPCLR register mask for ACT LED
+|-
+|colspan="2"|&nbsp;
+|-
+| <code>RPI4_GPIO_ACTLED_GPPUDSHIFT = 20;</code>
+| GPPUD register shift for ACT LED
+|-
+| <code>RPI4_GPIO_ACTLED_GPPUDMASK = BCM2838_GPPUD_MASK;</code>
+| GPPUD register mask for ACT LED
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi mailbox timeout''' <code> RPI4_MAILBOX_TIMEOUT_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_MAILBOX_TIMEOUT = 100;</code>
+| style="width: 50%;"|Default timeout to wait for mailbox calls to complete (Milliseconds)
+|-
+| <code>RPI4_MAILBOX_TIMEOUT_EX = 1000;</code>
+| Extended timeout to wait for mailbox calls to complete (Milliseconds)
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi local mailbox''' <code> RPI4_LOCAL_MAILBOX_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_LOCAL_MAILBOX_TIMEOUT = 100;</code>
+| style="width: 50%;"|Default timeout to wait for local mailbox calls to complete (Milliseconds)
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 20px; padding-bottom: 15px;">
+<div style="font-size: 14px; padding-left: 12px;">'''RPi framebuffer''' <code> RPI4_FRAMEBUFFER_* </code></div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+| <code>RPI4_FRAMEBUFFER_DESCRIPTION = 'BCM2838 Framebuffer';</code>
+| style="width: 50%;"|&nbsp;
+|-
+|}
+</div></div>
+<br />
 === Type definitions ===
 ----
-''To be documented''
+'''RPi4 framebuffer'''
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial;">
+<code>PRPi4Framebuffer = ^TRPi4Framebuffer;</code>
+<code>TRPi4Framebuffer = record</code>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+|colspan="2"|''Framebuffer Properties''
+|-
+| <code>Framebuffer:TFramebufferDevice;</code>
+| style="width: 50%;"|&nbsp;
+|-
+|colspan="2"|''RPi4 Properties''
+|-
+| <code>MultiDisplay:LongBool;</code>
+| &nbsp;
+|-
+| <code>DisplayNum:LongWord;</code>
+| &nbsp;
+|-
+| <code>DisplaySettings:TDisplaySettings;</code>
+| &nbsp;
+|-
+|}
+</div></div>
+<br />
 === Public variables ===
 ----
-''To be documented''
+'''RPi4 specific Ultibo variables'''
+{| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>RPi4Initialized:Boolean;</code>
+| style="width: 40%;"|
+|-
+|}
+{| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>RPi4CNTVOFFLow:LongWord = 0;</code>
+| style="width: 40%;"|The low 32 bits of the Virtual Counter Offset register at boot time (CPU0 only) (Set by Startup) Must be initialized to remain in .data or else rewritten to zero with .bss
+|-
+|}
+{| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>RPi4CNTVOFFHigh:LongWord = 0;</code>
+| style="width: 40%;"|The high 32 bits of the Virtual Counter Offset register at boot time (CPU0 only) (Set by Startup) Must be initialized to remain in .data or else rewritten to zero with .bss
+|-
+|}
+'''Timer register'''
+{| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>TimerRegisters:PBCM2838SystemTimerRegisters;</code>
+| style="width: 40%;"|
+|-
+|}
+'''Mailbox register'''
+{| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>Mailbox0Registers:PBCM2838Mailbox0Registers;</code>
+| style="width: 40%;"|
+|-
+|}
+ {| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>Mailbox1Registers:PBCM2838Mailbox1Registers;</code>
+| style="width: 40%;"|
+|-
+|}
+'''Interrupt device'''
+{| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>GICDevice:PGICDevice;</code>
+| style="width: 40%;"|
+|-
+|}
+{| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>GICAvailable:LongWord = RPI4_GIC_AVAILABLE;</code>
+| style="width: 40%;"|The status of the GIC interrupt controller, determined during boot.
+|-
+|}
+'''System call'''
+{| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>SystemCallEntries:array[0..RPI4_SWI_COUNT - 1] of TSystemCallEntry;</code>
+| style="width: 40%;"|
+|-
+|}
+'''Watchdog register'''
+{| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>WatchdogRegisters:PBCM2838PMWatchdogRegisters;</code>
+| style="width: 40%;"|
+|-
+|}
+'''ARM local register'''
+{| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>ARMLocalRegisters:PBCM2838ARMLocalRegisters;</code>
+| style="width: 40%;"|
+|-
+|}
+'''Virtual GPIO'''
+{| class="wikitable" style="font-size: 14px; text-align: left; width: 100%; height: 50px;"
+|-
+| <code>VirtualGPIOBuffer:TBCM2838VirtualGPIOBuffer;</code>
+| style="width: 40%;"|
+|-
+|}
+<br />
 === Function declarations ===
 ----
-''To be documented''
+'''Initialization functions'''
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4Init;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4SecondarySwitch;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Secondary CPU switch from HYP mode handler</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4SecondarySecure;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Secondary CPU switch to secure mode handler</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4SecondaryHandler;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Secondary CPU startup handler routine</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+'''RPi4 platform functions'''
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4SMPInit;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4BoardInit;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4MemoryInit;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4ClockInit;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4PowerInit;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4MailboxInit;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4InterruptInit;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4PeripheralInit;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4FramebufferInit;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4PageTableInit;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Initialize the Hardware Page Tables before enabling the MMU (LPAE version)</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4PageTableInitLegacy;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Initialize the Hardware Page Tables before enabling the MMU (Legacy version)</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4PowerLEDEnable;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4PowerLEDOn;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4PowerLEDOff;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4ActivityLEDEnable;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4ActivityLEDOn;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4ActivityLEDOff;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4MailboxReceive(Mailbox,Channel:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Receive from specified mailbox on specified channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| Data = first 28 bits, Channel = last 4 bits
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4MailboxSend(Mailbox,Channel,Data:LongWord);</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Send to specified mailbox on specified channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| Data = first 28 bits, Channel = last 4 bits
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4MailboxCall(Mailbox,Channel,Data:LongWord; var Response:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Perform a transaction (Send/Receive) to specified mailbox on specified channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| Data = first 28 bits, Channel = last 4 bits
+Data pointer must be 16 byte aligned to allow for the 4 bit channel number
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4MailboxCallEx(Mailbox,Channel,Data:LongWord; var Response:LongWord; Timeout:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Perform a transaction (Send/Receive) to specified mailbox on specified channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| Data = first 28 bits, Channel = last 4 bits
+Data pointer must be 16 byte aligned to allow for the 4 bit channel number
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4MailboxPropertyCall(Mailbox,Channel:LongWord; Data:Pointer; var Response:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Perform a property tag transaction (Send/Receive) to specified mailbox on specified channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| Data = first 28 bits, Channel = last 4 bits
+Data pointer must be 16 byte aligned to allow for the 4 bit channel number
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4MailboxPropertyCallEx(Mailbox,Channel:LongWord; Data:Pointer; var Response:LongWord; Timeout:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Perform a property tag transaction (Send/Receive) to specified mailbox on specified channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| Data = first 28 bits, Channel = last 4 bits
+Data pointer must be 16 byte aligned to allow for the 4 bit channel number
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4MailboxPropertyTag(Tag:LongWord; Data:Pointer; Size:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Request a property tag (Get/Set) from the mailbox property channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Data
+| Data does not need to include mailbox property channel header or footer. Data pointer does not need any specific alignment or caching attributes.
+|-
+! Size
+| Size must be a multiple of 4 bytes. Size must include the size of the request and response which use the same buffer.
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4RequestExIRQ(CPUID,Number:LongWord; Handler:TInterruptHandler; HandlerEx:TInterruptExHandler; Parameter:Pointer):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Request registration of the supplied extended handler to the specified IRQ number</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ReleaseExIRQ(CPUID,Number:LongWord; Handler:TInterruptHandler; HandlerEx:TInterruptExHandler; Parameter:Pointer):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Request deregistration of the supplied extended handler from the specified IRQ number</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4RequestExFIQ(CPUID,Number:LongWord; Handler:TInterruptHandler; HandlerEx:TInterruptExHandler; Parameter:Pointer):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Request registration of the supplied extended handler to the specified FIQ number</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ReleaseExFIQ(CPUID,Number:LongWord; Handler:TInterruptHandler; HandlerEx:TInterruptExHandler; Parameter:Pointer):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Request deregistration of the supplied extended handler from the specified FIQ number</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4RequestIPI(CPUID,Number:LongWord; Handler:TIPIHandler; Parameter:Pointer):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Request registration of the supplied handler to the specified IPI number</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ReleaseIPI(CPUID,Number:LongWord; Handler:TIPIHandler; Parameter:Pointer):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Request deregistration of the supplied handler from the specified IPI number</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4RegisterInterrupt(Number,Mask,Priority,Flags:LongWord; Handler:TSharedInterruptHandler; Parameter:Pointer):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Request registration of the supplied handler to the specified interrupt number (Where Applicable)</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Number
+| The interrupt number to register the hanlder for
+|-
+! Mask
+| The mask of CPUs to register the handler for (eg CPU_MASK_0, CPU_MASK_1) (Where Applicable)
+|-
+! Priority
+| The priroty level of the interrupt to be registered (eg INTERRUPT_PRIORITY_MAXIMUM) (Where Applicable)
+|-
+! Flags
+| The flags to control the registration of the interrupt (eg INTERRUPT_FLAG_SHARED) (Where Applicable)
+|-
+! Handler
+| The shared interrupt handler to be called when the interrupt occurs
+|-
+! Parameter
+| A pointer to be passed to the handler when the interrupt occurs (Optional)
+|-
+! Return
+| ERROR_SUCCESS if the callback was scheduled successfully or another error code on failure
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4DeregisterInterrupt(Number,Mask,Priority,Flags:LongWord; Handler:TSharedInterruptHandler; Parameter:Pointer):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Request deregistration of the supplied handler from the specified interrupt number (Where Applicable)</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Number
+| The interrupt number to deregister the hanlder for
+|-
+! Mask
+| The mask of CPUs to deregister the handler for (eg CPU_MASK_0, CPU_MASK_1) (Where Applicable)
+|-
+! Priority
+| The priroty level of the interrupt to be deregistered (eg INTERRUPT_PRIORITY_MAXIMUM) (Where Applicable)
+|-
+! Flags
+| The flags to control the deregistration of the interrupt (eg INTERRUPT_FLAG_SHARED, INTERRUPT_FLAG_LOCAL, INTERRUPT_FLAG_FIQ) (Where Applicable)
+|-
+! Handler
+| The shared interrupt handler to be called when the interrupt occurs
+|-
+! Parameter
+| A pointer to be passed to the handler when the interrupt occurs (Optional)
+|-
+! Return
+| ERROR_SUCCESS if the callback was scheduled successfully or another error code on failure
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4RegisterSystemCallEx(CPUID,Number:LongWord; Handler:TSystemCallHandler; HandlerEx:TSystemCallExHandler):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Request registration of the supplied extended handler to the specified System Call number</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! CPUID
+| The CPU ID to register the System Call against (or CPU_ID_ALL)
+|-
+! Number
+| The System Call number to be registered
+|-
+! Handler
+| The handler function to be registered
+|-
+! HandlerEx
+| The extended handler function to be registered
+|-
+! Note
+| Only one of Handler or HandlerEx can be specified
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4DeregisterSystemCallEx(CPUID,Number:LongWord; Handler:TSystemCallHandler; HandlerEx:TSystemCallExHandler):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Request deregistration of the supplied extended handler from the specified System Call number</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! CPUID
+| The CPU ID to deregister the System Call from (or CPU_ID_ALL)
+|-
+! Number
+| The System Call number to be deregistered
+|-
+! Handler
+| The handler function to be deregistered
+|-
+! HandlerEx
+| The extended handler function to be deregistered
+|-
+! Note
+| Only one of Handler or HandlerEx can be specified
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4GetInterruptEntry(Number,Instance:LongWord; var Interrupt:TInterruptEntry):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the interrupt entry for the specified interrupt number and instance</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4GetLocalInterruptEntry(CPUID,Number,Instance:LongWord; var Interrupt:TInterruptEntry):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the local interrupt entry for the specified interrupt number and instance</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4GetSoftwareInterruptEntry(CPUID,Number,Instance:LongWord; var Interrupt:TInterruptEntry):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the software interrupt entry for the specified interrupt number and instance</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4GetSystemCallEntry(Number:LongWord):TSystemCallEntry;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the system call entry for the specified system call number</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4SystemRestart(Delay:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4SystemShutdown(Delay:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4SystemGetCommandLine:String;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Command Line from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4CPUGetMemory(var Address:PtrUInt; var Length:UInt64):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the CPU Memory from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4GPUGetState:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4GPUGetMemory(var Address:PtrUInt; var Length:UInt64):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the GPU Memory from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4BoardGetModel:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Board Model from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4BoardGetSerial:Int64;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Board Serial from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4BoardGetRevision:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Board Revision from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4BoardGetMACAddress:String;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Board MAC Address from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ChipGetRevision:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Chip Revision from the revision register</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FirmwareGetRevision:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Firmware Revision from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FirmwareGetThrottled:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Firmware Throttling state from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4PowerGetWait(PowerId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Power Wait from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4PowerGetState(PowerId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Power State from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4PowerSetState(PowerId,State:LongWord; Wait:Boolean):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the Power State in the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| Power Lock not required due to Mailbox Property Call serialization
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ClockGetCount:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Gets the current system clock count (32 least significant bits of total)</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| On the Raspberry Pi this comes from the System Timer free running counter which runs at 1MHz and therefore overflows every 4295 seconds
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ClockGetTotal:Int64;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Gets the total system clock count</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| On the Raspberry Pi this comes from the System Timer free running counter which runs at 1MHz, the clock interrupt also uses this timer to increment the clock every second and therefore keep time.
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ClockGetRate(ClockId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Clock Rate from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ClockSetRate(ClockId,Rate:LongWord; Turbo:Boolean):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the Clock Rate in the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ClockGetState(ClockId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Clock State from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ClockSetState(ClockId,State:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the Clock State in the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ClockGetMinRate(ClockId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Clock Min Rate from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ClockGetMaxRate(ClockId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Clock Max Rate from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4TurboGetState(TurboId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Turbo State from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4TurboSetState(TurboId,State:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the Turbo State in the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4VoltageGetValue(VoltageId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Voltage Value from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4VoltageSetValue(VoltageId,Value:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the Voltage Value in the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4VoltageGetMinValue(VoltageId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Voltage Min Value from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4VoltageGetMaxValue(VoltageId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Voltage Max Value from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4TemperatureGetCurrent(TemperatureId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Temperature Current from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4TemperatureGetMaximum(TemperatureId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Temperature Maximum Model from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4GPUMemoryAllocate(Length,Alignment,Flags:LongWord):THandle;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Allocate GPU Memory from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4GPUMemoryRelease(Handle:THandle):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Release GPU Memory from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4GPUMemoryLock(Handle:THandle):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Lock GPU Memory from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4GPUMemoryUnlock(Handle:THandle):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Unlock GPU Memory from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4GPUExecuteCode(Address:Pointer; R0,R1,R2,R3,R4,R5:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Execute GPU Code from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4DispmanxHandleGet(Resource:THandle):THandle;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Dispmanx Memory Handle from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4EDIDBlockGet(Block:LongWord; Buffer:Pointer; Length:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get EDID Block from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferAllocate(Alignment:LongWord; var Address,Length:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Allocate Framebuffer from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferRelease:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Release Framebuffer from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetState(State:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer State (Blank Screen) from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetDimensions(var Width,Height,Top,Bottom,Left,Right:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Framebuffer Dimensions from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetPhysical(var Width,Height:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Framebuffer Physical size from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetPhysical(var Width,Height:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer Physical size from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferTestPhysical(var Width,Height:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Test Framebuffer Physical size from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetVirtual(var Width,Height:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Framebuffer Virtual size from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetVirtual(var Width,Height:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer Virtual size from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferTestVirtual(var Width,Height:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Test Framebuffer Virtual size from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetDepth(var Depth:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Framebuffer Depth (Bits per pixel) from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetDepth(var Depth:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer Depth (Bits per pixel) from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferTestDepth(var Depth:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Test Framebuffer Depth (Bits per pixel) from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetPixelOrder(var Order:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Framebuffer Pixel Order (RGB) from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetPixelOrder(var Order:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer Pixel Order (RGB) from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferTestPixelOrder(var Order:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Test Framebuffer Pixel Order (RGB) from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetAlphaMode(var Mode:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Framebuffer Alpha Mode from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetAlphaMode(var Mode:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer Alpha Mode from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferTestAlphaMode(var Mode:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Test Framebuffer Alpha Mode from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetPitch:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Framebuffer Pitch (Bytes per line) from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetOffset(var X,Y:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Framebuffer Virtual Offset from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetOffset(var X,Y:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer Virtual Offset from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferTestOffset(var X,Y:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Test Framebuffer Virtual Offset from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetOverscan(var Top,Bottom,Left,Right:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Framebuffer Overscan from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetOverscan(var Top,Bottom,Left,Right:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer Overscan from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferTestOverscan(var Top,Bottom,Left,Right:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Test Framebuffer Overscan from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetPalette(Buffer:Pointer;Length:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Framebuffer Palette from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetPalette(Start,Count:LongWord; Buffer:Pointer; Length:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer Palette from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferTestPalette(Start,Count:LongWord; Buffer:Pointer; Length:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Test Framebuffer Palette from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetLayer(var Layer:LongInt):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get Framebuffer Layer from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetLayer(var Layer:LongInt):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer Layer from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferTestLayer(var Layer:LongInt):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Test Framebuffer Layer from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferTestVsync:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Test Framebuffer Vertical Sync from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetVsync:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer Vertical Sync from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetBacklight(Brightness:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Framebuffer Backlight Brightness from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetNumDisplays(var NumDisplays:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the number of displays from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetDisplayId(DisplayNum:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the display id for the specified display number from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferSetDisplayNum(DisplayNum:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the display number that all framebuffer requests will refer to using the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferGetDisplaySettings(DisplayNum:LongWord; var DisplaySettings:TDisplaySettings):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the display settings for the specified display number from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferDisplayIdToName(DisplayId:LongWord):String;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the name for the specified display id</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4TouchGetBuffer(var Address:PtrUInt):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Touchscreen buffer from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| On current firmware versions calling TouchGetBuffer will allocate a buffer from GPU memory and render subsequent calls to TouchSetBuffer ineffective.
+After an initial call to TouchSetBuffer calls to TouchGetBuffer will always return the CPU allocated buffer.
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4TouchSetBuffer(Address:PtrUInt):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the Touchscreen buffer in the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4VirtualGPIOGetBuffer(var Address:PtrUInt):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the Virtual GPIO buffer from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4VirtualGPIOSetBuffer(Address:PtrUInt):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set the Virtual GPIO buffer in the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4CursorSetDefault:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Cursor Default (Pixels) from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4CursorSetInfo(Width,Height,HotspotX,HotspotY:LongWord; Pixels:Pointer; Length:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Cursor Info (Pixels) from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4CursorSetState(Enabled:Boolean; X,Y:LongWord; Relative:Boolean):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Set Cursor State (Enable, X, Y) from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Relative
+| X, Y is relative to Display (Virtual) not Framebuffer (Physical)
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4DMAGetChannels:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Get the available DMA Channels from the Mailbox property tags channel</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4VirtualGPIOInputGet(Pin:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4VirtualGPIOOutputSet(Pin,Level:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4VirtualGPIOFunctionSelect(Pin,Mode:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+'''RPi4 thread functions'''
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4SchedulerInit;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Initialize the scheduler interrupt on the boot CPU</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4SchedulerStart(CPUID:LongWord);</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Initialize the scheduler interrupt on the specified secondary CPU</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4SecondaryBoot(CPUID:LongWord);</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+'''RPi4 SWI functions'''
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4DispatchSWI(CPUID:LongWord; Thread:TThreadHandle; Request:PSystemCallRequest):TThreadHandle;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Process an SWI request</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| Called by ARMv7/8SoftwareInterruptHandler in PlatformARMv7/8
+A DataMemoryBarrier is executed before and after calling this function.
+|-
+|}
+</div></div>
+<br />
+'''RPi4 clock functions'''
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4ClockInterrupt(Parameter:Pointer);</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Interrupt handler function for the clock interrupt</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| This schedules another clock interrupt to occur CLOCK_CYCLES_PER_TICK in the future, then updates ClockTicks and ClockSeconds and checks for timers to trigger.
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4ClockUpdate(Cycles:LongWord; var Last:LongWord);</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Setup a clock interrupt to trigger after the specified number of clock cycles</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Cycles
+| Number of cycles after which the timer interrupt is to be triggered
+|-
+! Note
+| This refers to native clock cycles as specified by CLOCK_FREQUENCY
+|-
+|}
+</div></div>
+<br />
+'''RPi4 scheduler functions'''
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4SchedulerInterrupt(CPUID:LongWord; Thread:TThreadHandle; Parameter:Pointer):TThreadHandle;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Interrupt handler function for the scheduler interrupt</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| This schedules another scheduler interrupt to occur SCHEDULER_CLOCKS_PER_INTERRUPT in the future, then checks for threads to wakeup or timeout and the next thread to schedule.
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4SchedulerUpdate(Cycles:LongWord; var Last:LongWord);</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Setup a scheduler interrupt to trigger after the specified number of clock cycles</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Cycles
+| Number of cycles after which the scheduler interrupt is to be triggered
+|-
+! Note
+| This refers to native clock cycles as specified by RPI4_GENERIC_TIMER_FREQUENCY
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4SchedulerSystemCall(Request:PSystemCallRequest);</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' System Call handler for the scheduler</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| This is registered to receive requests for the SYSTEM_CALL_CONTEXT_SWITCH and will perform a context switch from within an SWI
+|-
+|}
+</div></div>
+<br />
+'''RPi4 framebuffer functions'''
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferDeviceAllocate(Framebuffer:PFramebufferDevice; Properties:PFramebufferProperties):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Allocate a framebuffer using the Mailbox Property Tags</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferDeviceAllocateAlt(Framebuffer:PFramebufferDevice; Properties:PFramebufferProperties):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Allocate a framebuffer using a simple Mailbox Call</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferDeviceRelease(Framebuffer:PFramebufferDevice):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferDeviceBlank(Framebuffer:PFramebufferDevice; Blank:Boolean):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferDeviceCommit(Framebuffer:PFramebufferDevice; Address:PtrUInt; Size,Flags:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4FramebufferDeviceSetBacklight(Framebuffer:PFramebufferDevice; Brightness:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+'''RPi4 helper functions'''
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4Wait;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4LongWait;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4ShortWait;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4SlowBlink;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4FastBlink;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4BootBlink;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Blink the Activity LED without dependency on any other RTL setup</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4BootOutput(Value:LongWord);</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Output characters to UART0 without dependency on any other RTL setup</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| This function is primarily intended for testing QEMU boot because it doesn't initialize the UART and won't work on real hardware.
+Based on hexstrings() function by dwelch67 (https://github.com/dwelch67)
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4BootConsoleStart;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4BootConsoleWrite(const Value:String);</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">procedure RPi4BootConsoleWriteEx(const Value:String; X,Y:LongWord);</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4BootConsoleGetX:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4BootConsoleGetY:LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' To be documented</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ConvertPowerIdRequest(PowerId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Convert Ultibo Power Id to BCM2838 Power Id</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ConvertPowerStateRequest(PowerState:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Convert Ultibo Power State to BCM2838 Power State</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ConvertPowerStateResponse(PowerState:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Convert BCM2838 Power State to Ultibo Power State</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ConvertClockIdRequest(ClockId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Convert Ultibo Clock Id to BCM2838 Clock Id</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ConvertClockStateRequest(ClockState:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Convert Ultibo Clock State to BCM2838 Clock State</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ConvertClockStateResponse(ClockState:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Convert BCM2838 Clock State to Ultibo Clock State</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ConvertVoltageIdRequest(VoltageId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Convert Ultibo Voltage Id to BCM2838 Voltage Id</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
+<div class="toccolours mw-collapsible mw-collapsed" style="border: 1; font-family: arial; padding-top: 0px; padding-bottom: 15px;">
+<pre style="border: 0; padding-bottom:0px;">function RPi4ConvertTemperatureIdRequest(TemperatureId:LongWord):LongWord;</pre>
+<div style="font-size: 14px; padding-left: 12px;">'''Description:''' Convert Ultibo Temperature Id to BCM2838 Temperature Id</div>
+<div class="mw-collapsible-content" style="text-align: left; padding-left: 5px;">
+{| class="wikitable" style="font-size: 14px; background: white;"
+|-
+! Note
+| None documented
+|-
+|}
+</div></div>
+<br />
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