3d9d6198c8
How To Run:
see TencentOS-tiny\board\ALPHA_I.MX_emmc_256ddr\README.md
TODO Next:
1. VFP support
2. fault diagnosis support
3. qemu vexpress ca9 support
4. raspberry pi support
5. SMP support
151 lines
2.9 KiB
ArmAsm
151 lines
2.9 KiB
ArmAsm
.equ MODE_USR, 0x10
|
|
.equ MODE_FIQ, 0x11
|
|
.equ MODE_IRQ, 0x12
|
|
.equ MODE_SVC, 0x13
|
|
.equ MODE_ABT, 0x17
|
|
.equ MODE_UND, 0x1B
|
|
.equ MODE_SYS, 0x1F
|
|
|
|
.equ BIT_I, 0x80 @ when I bit is set, IRQ is disabled
|
|
.equ BIT_F, 0x40 @ when F bit is set, FIQ is disabled
|
|
|
|
.equ STACK_SIZE_USR, 0x00000100
|
|
.equ STACK_SIZE_FIQ, 0x00000100
|
|
.equ STACK_SIZE_IRQ, 0x00001000
|
|
.equ STACK_SIZE_ABT, 0x00000100
|
|
.equ STACK_SIZE_UND, 0x00000100
|
|
.equ STACK_SIZE_SYS, 0x00000800
|
|
.equ STACK_SIZE_SVC, 0x00001000
|
|
|
|
.syntax unified
|
|
|
|
.section ".text.vector", "ax"
|
|
.code 32
|
|
.align 0
|
|
.global _start
|
|
_start:
|
|
_vector:
|
|
ldr pc, vector_reset
|
|
ldr pc, vector_undefined
|
|
ldr pc, vector_swi
|
|
ldr pc, vector_prefetch_abort
|
|
ldr pc, vector_data_abort
|
|
ldr pc, vector_reserved
|
|
ldr pc, vector_irq
|
|
ldr pc, vector_fiq
|
|
|
|
.align 3
|
|
|
|
vector_reset:
|
|
.word arm_reset
|
|
|
|
vector_undefined:
|
|
.word arm_undefined
|
|
|
|
vector_swi:
|
|
.word arm_syscall
|
|
|
|
vector_prefetch_abort:
|
|
.word arm_prefetch_abort
|
|
|
|
vector_data_abort:
|
|
.word arm_data_abort
|
|
|
|
vector_reserved:
|
|
.word arm_reserved
|
|
|
|
vector_irq:
|
|
.word arm_irq
|
|
|
|
vector_fiq:
|
|
.word arm_fiq
|
|
|
|
.section ".text", "ax"
|
|
.global arm_reset
|
|
arm_reset:
|
|
.L__cache_disable:
|
|
mrc p15, 0, r12, c1, c0, 0 /* read SCTLR */
|
|
bic r12, #(1 << 12) /* i-cache disable */
|
|
bic r12, #(1 << 2 | 1 << 0) /* d-cache, mmu disable */
|
|
mcr p15, 0, r12, c1, c0, 0 /* write SCTLR */
|
|
|
|
/* set up the stack */
|
|
.L__stack_setup:
|
|
cpsid i, #MODE_IRQ /* irq */
|
|
ldr sp, =__irq_stack_limit
|
|
|
|
cpsid i, #MODE_FIQ /* fiq */
|
|
ldr sp, =__fiq_stack_limit
|
|
|
|
cpsid i, #MODE_ABT /* abort */
|
|
ldr sp, =__abt_stack_limit
|
|
|
|
cpsid i, #MODE_UND /* undefined */
|
|
ldr sp, =__und_stack_limit
|
|
|
|
cpsid i, #MODE_SYS /* system */
|
|
ldr sp, =__sys_stack_limit
|
|
|
|
cpsid i, #MODE_SVC /* supervisor */
|
|
ldr sp, =__svc_stack_limit
|
|
|
|
/* init vector table */
|
|
.L__vector_setup:
|
|
dsb
|
|
isb
|
|
ldr r0, =_vector
|
|
mcr p15, 0, r0, c12, c0, #0 /* write VBAR */
|
|
dsb
|
|
isb
|
|
|
|
/* clear bss */
|
|
.L__bss_clear:
|
|
ldr r0, =__bss_start__
|
|
ldr r1, =__bss_end__
|
|
mov r2, #0
|
|
|
|
.L__bss_loop:
|
|
cmp r0, r1
|
|
strlt r2, [r0], #4
|
|
blt .L__bss_loop
|
|
|
|
bl main
|
|
b .
|
|
|
|
.section ".bss.prebss.exc_stk", "wa"
|
|
.bss
|
|
.align 2
|
|
|
|
__usr_stack_base:
|
|
.space STACK_SIZE_USR
|
|
__usr_stack_limit:
|
|
|
|
__fiq_stack_base:
|
|
.space STACK_SIZE_FIQ
|
|
__fiq_stack_limit:
|
|
|
|
__irq_stack_base:
|
|
.space STACK_SIZE_IRQ
|
|
__irq_stack_limit:
|
|
|
|
__abt_stack_base:
|
|
.space STACK_SIZE_ABT
|
|
__abt_stack_limit:
|
|
|
|
__und_stack_base:
|
|
.space STACK_SIZE_UND
|
|
__und_stack_limit:
|
|
|
|
__sys_stack_base:
|
|
.space STACK_SIZE_SYS
|
|
__sys_stack_limit:
|
|
|
|
__svc_stack_base:
|
|
.space STACK_SIZE_SVC
|
|
__svc_stack_limit:
|
|
|
|
.size __usr_stack_base, . - __usr_stack_base
|
|
|
|
.end
|
|
|