Unit PlatformARM

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Description

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Ultibo Platform Interface unit for ARM

Constants

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ARM mode ARM_MODE_*

Bits 4..0 in the ARM program status register
See: A2.2 Processor Modes of the ARM Architecture Reference Manual and also A2.5.7 The mode bits
See also: B1.3.1 ARM processor modes of the ARM Architecture Reference Manual (ARMv7-A and ARMv7-R edition)
ARM_MODE_USR = $10;	Normal User Mode
ARM_MODE_FIQ = $11;	FIQ Processing Fast Interrupts Mode
ARM_MODE_IRQ = $12;	IRQ Processing Standard Interrupts Mode
ARM_MODE_SVC = $13;	Supervisor Processing Software Interrupts Mode
ARM_MODE_MON = $16;	Secure Monitor Mode (For Secure/Non Secure Switching)
ARM_MODE_MON = $16;	Secure Monitor Mode (For Secure/Non Secure Switching)
ARM_MODE_ABT = $17;	Abort Processing memory Faults Mode
ARM_MODE_HYP = $1A;	Hypervisor Mode
ARM_MODE_UND = $1B;	Undefined Processing Undefined Instructions Mode
ARM_MODE_SYS = $1F;	System Running Priviledged Operating System Tasks Mode
ARM_MODE_BITS = $0000001F;	Mask of the mode bits in the program status register

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ARM interrupt disable ARM_I_*

Bits 7 and 6 in the ARM program status register
See: A2.5.6 "The interrupt disable bits" of the ARM Architecture Reference Manual
ARM_I_BIT = $00000080;	IRQs disabled when set to 1
ARM_F_BIT = $00000040;	FIQs disabled when set to 1

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ARM thumb and jazelle ARM_*_BIT

Bits 24 and 5 in the ARM program status register
See: A2.5.8 "The T and J bits" of the ARM Architecture Reference Manual
ARM_T_BIT = $00000020;	Thumb mode enabled when set to 1
ARM_J_BIT = $01000000;	Jazelle mode enabled when set to 1

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ARM abort ARM_A_*

Bit 8 in the ARM program status register
ARM_A_BIT = $00000100;	Data Abort masked when set to 1

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ARM boot tag ATAG_*

ATAG_NONE = $00000000;
ATAG_CORE = $54410001;
ATAG_MEM = $54410002;
ATAG_VIDEOTEXT = $54410003;
ATAG_RAMDISK = $54410004;
ATAG_INITRD = $54410005;	Deprecated
ATAG_INITRD2 = $54420005;
ATAG_SERIAL = $54410006;
ATAG_REVISION = $54410007;
ATAG_VIDEOLFB = $54410008;
ATAG_CMDLINE = $54410009;
ARMTAGS_INITIAL = $FFFFFFFF;

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Device tree blob DTB_*

DTB_SIGNATURE = $d00dfeed;

See: https://github.com/devicetree-org/devicetree-specification/releases/download/v0.3/devicetree-specification-v0.3.pdf

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ARM machine type ARM_MACHINE_*

ARM_MACHINE_VERSATILE_PB = $00000183;
ARM_MACHINE_BCM2708 = $00000C42;
ARM_MACHINE_BCM2709 = $00000C42;	BCM2709 uses the same Machine Type as BCM2708
ARM_MACHINE_BCM2710 = $00000C42;	BCM2710 uses the same Machine Type as BCM2708
ARM_MACHINE_BCM2711 = $00000C42;	BCM2711 uses the same Machine Type as BCM2708

Type definitions

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ARM boot tag header

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PARMTagHeader = ^TARMTagHeader;

TARMTagHeader = record

Note: ARM Boot Tag Structure Definitions
Size:LongWord;	Size of tag, in words (32bit), including the header
Tag:LongWord;	One of the ATAG_* values from above

ARM tag core

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PARMTagCore = ^TARMTagCore;

TARMTagCore = record

Note: Core parameters (ATAG_CORE)
Flags:LongWord;	Bit 0 = read-only
PageSize:LongWord;	Systems page size (usually 4k)
RootDev:LongWord;	Root device number

ARM tag memory

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PARMTagMemory = ^TARMTagMemory;

TARMTagMemory = record

Note: Description of memory region (ATAG_MEM)
Size:LongWord;
Start:LongWord;

ARM tag video text

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PARMTagVideoText = ^TARMTagVideoText;

TARMTagVideoText = record

Note: Description of VGA text type displays (ATAG_VIDEOTEXT)
X:Byte;	Width of display
Y:Byte;	Height of display
Video_page:Word;
Video_mode:Byte;
Video_cols:Byte;
Video_ega_bx:Word;
Video_lines:Byte;
Video_isvga:Byte;
Video_points:Word;

ARM tag ramdisk

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PARMTagRamdisk = ^TARMTagRamdisk;

TARMTagRamdisk = record

Note: Description of how the ramdisk will be used by the kernel (ATAG_RAMDISK)
Flags:LongWord;	Bit 0 = load, Bit 1 = prompt
Size:LongWord;	Decompressed ramdisk size in _kilo_ bytes
Start:LongWord;	Starting block of floppy-based RAM disk image

Tag initialize RD

TagInitRdCount:LongWord;

Number of ARM INITRD Tags found during parse (Deprecated)

Tag initialize RD2

TagInitRd2Count:LongWord;

Number of ARM INITRD2 Tags found during parse

TagInitRd2Start:LongWord;

TagInitRd2Size:LongWord;

ARM tag serial

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PARMTagSerial = ^TARMTagSerial;

TARMTagSerial = record

Note: Board serial number (ATAG_SERIAL)
Low:LongWord;
High:LongWord;

ARM tag revision

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PARMTagRevision = ^TARMTagRevision;

TARMTagRevision = record

Note: Board revision (ATAG_REVISION)
Revision:LongWord;

ARM tag video framebuffer

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PARMTagVideoFB = ^TARMTagVideoFB;

TARMTagVideoFB = record

Note: Description of the parameters for a linear framebuffer type display (ATAG_VIDEOLFB)
Lfb_width:Word;
Lfb_height:Word;
Lfb_depth:Word;
Lfb_linelength:Word;
Lfb_base:LongWord;
Lfb_size:LongWord;
Red_size:Byte;
Red_pos:Byte;
Green_size:Byte;
Green_pos:Byte;
Blue_size:Byte;
Blue_pos:Byte;
Rsvd_size:Byte;
Rsvd_pos:Byte;

ARM tag command

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PARMTagCommand = ^TARMTagCommand;

TARMTagCommand = record

Note: Commandline for the kernel (ATAG_CMDLINE)
Cmdline:array[0..0] of AnsiChar;	This is the minimum size

ARM boot tag

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PARMTag = ^TARMTag;

TARMTag = record

Note: Format of ARM Boot Tag
Header:TARMTagHeader;
case Integer of
0:(Core:TARMTagCore);
1:(Memory:TARMTagMemory);
2:(VideoText:TARMTagVideoText);
3:(Ramdisk:TARMTagRamdisk);
4:(InitRd2:TARMTagInitRd2);
5:(Serial:TARMTagSerial);
6:(Revision:TARMTagRevision);
7:(VideoFB:TARMTagVideoFB);
8:(Command:TARMTagCommand)

Device tree blob header

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PDTBHeader = ^TDTBHeader;

TDTBHeader = packed record

Magic:LongWord;	The value 0xd00dfeed (big-endian)
TotalSize:LongWord;	The total size in bytes of the devicetree data structure (big-endian)
StructureOffset:LongWord;	The offset in bytes of the structure block from the beginning of the header (big-endian)
StringsOffset:LongWord;	The offset in bytes of the strings block from the beginning of the header (big-endian)
ReservationOffset:LongWord;	The offset in bytes of the memory reservation block from the beginning of the header (big-endian)
Version:LongWord;	The version of the devicetree data structure (big-endian)
CompatibleVersion:LongWord;	The lowest version of the devicetree data structure with which the version used is backwards compatible (big-endian)
BootCPUID:LongWord;	The physical ID of the system’s boot CPU (big-endian)
StringsSize:LongWord;	The length in bytes of the strings block section of the devicetree blob (big-endian)
StructureSize:LongWord;	The length in bytes of the structure block section of the devicetree blob (big-endian)

ARM wait

TARMWait = procedure;

ARM long wait

TARMLongWait = procedure;

ARM short wait

TARMShortWait = procedure;

ARM slow blink

TARMSlowBlink = procedure;

ARM fast blink

TARMFastBlink = procedure;

Public variables

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ARM specific variables

ARMInitialized:Boolean;

ARMBootMode:LongWord = 0;

The ARM Mode that the processor was in at boot time (Set by Startup)

ARMBootVectors:LongWord = 0;

The Vector Base Address that was current at boot time (Set by Startup)

ARMTagsAddress:PtrUInt = ARMTAGS_INITIAL;

Pointer to the ARM TAGS provided by the bootloader at startup (Set by Startup)

ARMMachineType:LongWord = 0;

ARM Machine Type provided by the bootloader at startup (Set by Startup)

ARMSecureBoot:LongWord = 1;

If 1 then startup will attempt to switch back to secure world during boot process (If supported by the ARM boot stub)

ARMEmulatorMode:LongWord = 0;

If 1 then startup detected that the machine is running in an emulator (If applicable) Note: These variables must be initialized to remain in .data or else they are rewritten to zero with .bss

ARM tags

ARMTagsCount:LongWord;

Number of ARM Tags found during parse

Tag none variables

TagNoneCount:LongWord;

Number of ARM NONE Tags found during parse

Tag core

TagCoreCount:LongWord;

Number of ARM CORE Tags found during parse

TagCoreFlags:LongWord;

TagCorePageSize:LongWord;

TagCoreRootDevice:LongWord;

Tag memory

TagMemoryCount:LongWord;

Number of ARM MEM Tags found during parse

TagMemorySize:LongWord;

Size of the last block reported by ARM Tags

TagMemoryStart:PtrUInt;

Start of the last block reported by ARM Tags

TagMemoryLength:LongWord;

Adjusted Size of the last block reported by ARM Tags

TagMemoryAddress:PtrUInt;

Adjusted Address of the last block reported by ARM Tags

Tag video text

TagVideoTextCount:LongWord;

Number of ARM VIDEOTEXT Tags found during parse

Tag ramdisk

TagRamdiskCount:LongWord;

Number of ARM RAMDISK Tags found during parse

Tag initialize RD2

TagInitRd2Count:LongWord;

Number of ARM INITRD2 Tags found during parse

Tag serial

TagSerialCount:LongWord;

Number of ARM SERIAL Tags found during parse

TagSerialNoLow:LongWord;

TagSerialNoHigh:LongWord;

Tag revision

TagRevisionCount:LongWord;

Number of ARM REVISION Tags found during parse

TagRevisionNo:LongWord;

Tag video framebuffer

TagVideoFBCount:LongWord;

Number of ARM VIDEOLFB Tags found during parse

Tag command

TagCmdCount:LongWord;

Number of ARM CMDLINE Tags found during parse

TagCommandSize:LongWord;

Length of the command line in characters (Including null terminator)

TagCommandCount:LongInt;

Count of parameters (space delimited) in the command line

TagCommandAddress:PAnsiChar;

Pointer to the start of the command line

Wait handlers

ARMWaitHandler:TARMWait;

ARMLongWaitHandler:TARMLongWait;

ARMShortWaitHandler:TARMShortWait;

Blink handlers

ARMSlowBlinkHandler:TARMSlowBlink;

ARMFastBlinkHandler:TARMFastBlink;

Function declarations

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Initialization functions

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procedure ARMInit;

Description: To be documented

Note	None documented

ARM platform functions

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procedure ARMParseBootTags;

Description: Extract some information from the ARM boot tag list and use it to load the memory manager, some other information is stored in variables for future use

Note	None documented

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function ExtractCommandLine(Value:PAnsiChar):Boolean;

Description: To be documented

Note	None documented

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function ExtractMemoryBlock(Address,Size:LongWord):Boolean;

Description: To be documented

Note	None documented

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function ExtractInitialRamdisk(Address,Size:LongWord):Boolean;

Description: To be documented

Note	None documented

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procedure ARMParseCommandLine;

Description: Setup argc, argv and cmdline and process known command line options

Note	None documented

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procedure ARMParseEnvironment;

Description: Setup envp and process known environment options

Note	None documented

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function ARMGetSP:PtrUInt; assembler; nostackframe;

Description: Get the current stack pointer (SP)

Note	None documented

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function ARMGetPC:PtrUInt; assembler; nostackframe;

Description: Get the current program counter (PC)

Note	None documented

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function ARMGetIRQ:Boolean; assembler; nostackframe;

Description: Get Interrupts (IRQ) state

Return	True is enabled, False if disabled (Returned in R0).

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procedure ARMEnableIRQ; assembler; nostackframe;

Description: Enable Interrupts (IRQ) unconditionally

Note	None documented

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procedure ARMDisableIRQ; assembler; nostackframe;

Description: Disable Interrupts (IRQ) unconditionally

Note	None documented

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function ARMSaveIRQ:TIRQMask; assembler; nostackframe;

Description: Disable Interrupts (IRQ) and return the previous state

Return	IRQ state when called (Returned in R0)

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function ARMRestoreIRQ(IRQMask:TIRQMask):TIRQMask; assembler; nostackframe;

Description: Restore Interrupts (IRQ) to a previous state

IRQMask	IRQ state to restore (Passed in R0)
Return	IRQ state when called (Returned in R0)

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function ARMGetFIQ:Boolean; assembler; nostackframe;

Description: Get Fast Interrupts (FIQ) state

Return	True is enabled, False if disabled (Returned in R0).

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procedure ARMEnableFIQ; assembler; nostackframe;

Description: Enable Fast Interrupts (FIQ) unconditionally

Note	None documented

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procedure ARMDisableFIQ; assembler; nostackframe;

Description: Disable Fast Interrupts (FIQ) unconditionally

Note	None documented

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function ARMSaveFIQ:TFIQMask; assembler; nostackframe;

Description: Disable Fast Interrupts (FIQ) and return the previous state

Return	FIQ state when called (Returned in R0)

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function ARMRestoreFIQ(FIQMask:TFIQMask):TFIQMask; assembler; nostackframe;

Description: Restore Fast Interrupts (FIQ) to a previous state

FIQMask	FIQ state to restore (Passed in R0)
Return	FIQ state when called (Returned in R0)

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procedure ARMEnableIRQFIQ; assembler; nostackframe;

Description: Enable Interrupts and Fast Interrupts (IRQ/FIQ) unconditionally

Note	None documented

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procedure ARMDisableIRQFIQ; assembler; nostackframe;

Description: Disable Interrupts and Fast Interrupts (IRQ/FIQ) unconditionally

Note	None documented

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function ARMSaveIRQFIQ:TIRQFIQMask; assembler; nostackframe;

Description: Disable Interrupts and Fast Interrupts (IRQ/FIQ) and return the previous state

Return	IRQ/FIQ state when called (Returned in R0)

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function ARMRestoreIRQFIQ(IRQFIQMask:TIRQFIQMask):TIRQFIQMask; assembler; nostackframe;

Description: Restore Interrupts and Fast Interrupts (IRQ/FIQ) to a previous state

IRQFIQMask	IRQ/FIQ state to restore (Passed in R0)
Return	IRQ/FIQ state when called (Returned in R0)

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function ARMGetAbort:Boolean; assembler; nostackframe;

Description: Get Abort state

Return	True is enabled, False if disabled (Returned in R0).

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procedure ARMEnableAbort; assembler; nostackframe;

Description: Enable Aborts unconditionally

Note	None documented

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procedure ARMDisableAbort; assembler; nostackframe;

Description: Disable Aborts unconditionally

Note	None documented

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function ARMSaveAbort:TAbortMask; assembler; nostackframe;

Description: Disable Aborts and return the previous state

Return	Abort state when called (Returned in R0)

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function ARMRestoreAbort(AbortMask:TAbortMask):TAbortMask; assembler; nostackframe;

Description: Restore Aborts to a previous state

AbortMask	Abort state to restore (Passed in R0)
Return	Abort state when called (Returned in R0)

ARM helper functions

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procedure ARMWait; inline;

Description: To be documented

Note	None documented

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procedure ARMLongWait; inline;

Description: To be documented

Note	None documented

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procedure ARMShortWait; inline;

Description: To be documented

Note	None documented

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procedure ARMSlowBlink; inline;

Description: To be documented

Note	None documented

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procedure ARMFastBlink; inline;

Description: To be documented

Note	None documented

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function ARMModeToString(ARMMode:LongWord):String;

Description: To be documented

Note	None documented

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