rockbox/utils/hwstub/stub/stmp/crt0.S

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969 B
ArmAsm
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.section .text,"ax",%progbits
.code 32
.align 0x04
.global start
start:
sub r7, pc, #8 /* Copy running address */
msr cpsr_c, #0xd3 /* enter supervisor mode, disable IRQ/FIQ */
/* Disable MMU, disable caching and buffering;
* use low exception range address */
mrc p15, 0, r0, c1, c0, 0
ldr r1, =0x3005
bic r0, r1
mcr p15, 0, r0, c1, c0, 0
/* Relocate to right address */
mov r2, r7
ldr r3, =_copystart
ldr r4, =_copyend
1:
cmp r4, r3
ldrhi r5, [r2], #4
strhi r5, [r3], #4
bhi 1b
mov r2, #0
mcr p15, 0, r2, c7, c5, 0 @ Invalidate ICache
/* Jump to real location */
ldr pc, =remap
remap:
/* clear bss */
ldr r2, =bss_start
ldr r3, =bss_end
mov r4, #0
1:
cmp r3, r2
strhi r4, [r2], #4
bhi 1b
/* jump to C code */
ldr sp, =oc_stackend
b main