Unit BootQEMUVPB

Return to Unit Reference

Description

---

Ultibo Initialization code for QEMU VersatilePB unit

QEMU VersatilePB

SoC: ARM926EJ-S (Emulated)

CPU: Cortex A8 (ARMv7) (1 @ ???MHz) or Cortex A53 (ARMv8) (1 @ ???MHz)

Cache: L1 16KB/L2 0KB or L1 ??KB/L2 ??KB

FPU: VFPV3 or VFP

GPU: (None)

RAM: 256MB

USB: PCI OHCI USB controller

LAN: SMC 91c111 Ethernet adapter

SD/MMC: PL181 MultiMedia Card Interface with SD card

WiFi: (None)

Bluetooth: (None)

Other:

PL190 Vectored Interrupt Controller

Four PL011 UARTs

PL110 LCD controller

PL050 KMI with PS/2 keyboard and mouse

PCI host bridge

PCI OHCI USB controller

LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices

GPIO/I2C/Watchdog/SP804 Timer

Boot QEMUVPB

The QMEU system emulator (qemu-system-arm) will load this code at address 0x00010000 onwards and set the following registers before jumping to this code.

R0 - Zero

R1 - Machine Type (Versatile_PB = 0x0183)

R2 - Address of the ARM Tags structure (Normally 0x0100)

On entry to this code the processor will be in the following state:

World - Secure

Mode - Supervisor (ARM_MODE_SVC)

MMU - Disabled

FPU - Disabled

L1 Data Cache - Disabled

L1 Instruction Cache - Disabled

Branch Predication - Disabled

Unaligned Data Access - Disabled

Ultibo switches the processor to System mode for all operations and remains in the Secure world.

The initialization process enables the MMU, FPU, L1 Cache and other performance optimizations.

Constants

---

None defined

Type definitions

---

None defined

Public variables

---

None defined

Function declarations

---

Boot functions

procedure Startup; assembler; nostackframe; [public, alias: '_START'];

Description: Entry point of Ultibo on QEMU VersatilePB, this will be the very first byte executed and will be loaded by QEMU at address 0x00010000

Note	None documented

procedure Vectors; assembler; nostackframe; 

Description: ARM exception vector table which is copied to address 0 by the StartupHandler

Note	See A2.6 "Exceptions" of the ARM Architecture Reference Manual

procedure StartupHandler; assembler; nostackframe;

Description: Startup handler routine executed to start the Ultibo kernel

Note	None documented

Return to Unit Reference