pokeemerald/asm/crt0.s
2016-11-01 12:10:55 -07:00

153 lines
3.1 KiB
ArmAsm

.include "constants/gba_constants.inc"
.syntax unified
.global Start
.text
.arm
Start: @ 8000000
b Init
.include "asm/rom_header.inc"
@ 80000C0
.word 0
.global GPIOPortData
GPIOPortData: @ 80000C4
.hword 0
.global GPIOPortDirection
GPIOPortDirection: @ 80000C6
.hword 0
.global GPIOPortReadEnable
GPIOPortReadEnable: @ 80000C8
.hword 0
.incbin "baserom.gba", 0xCA, 0x204 - 0xCA
.arm
.align 2, 0
.global Init
Init: @ 8000204
mov r0, PSR_IRQ_MODE
msr cpsr_cf, r0
ldr sp, sp_irq
mov r0, PSR_SYS_MODE
msr cpsr_cf, r0
ldr sp, sp_sys
ldr r1, =INTR_VECTOR
adr r0, InterruptMain
str r0, [r1]
ldr r1, =Main + 1
mov lr, pc
bx r1
b Init
.align 2, 0
sp_sys: .word IWRAM_END - 0x1c0
sp_irq: .word IWRAM_END - 0x60
.pool
.arm
.align 2, 0
.global InterruptMain
InterruptMain: @ 8000248
mov r3, REG_BASE
add r3, r3, 0x200
ldr r2, [r3, OFFSET_REG_IE - 0x200]
ldrh r1, [r3, OFFSET_REG_IME - 0x200]
mrs r0, spsr
stmdb sp!, {r0-r3,lr}
mov r0, 0
strh r0, [r3, OFFSET_REG_IME - 0x200]
and r1, r2, r2, lsr 16
mov r12, 0
ands r0, r1, INTR_FLAG_VCOUNT
bne InterruptMain_FoundIntr
add r12, r12, 0x4
mov r0, 0x1
strh r0, [r3, OFFSET_REG_IME - 0x200]
ands r0, r1, INTR_FLAG_SERIAL
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_TIMER3
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_HBLANK
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_VBLANK
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_TIMER0
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_TIMER1
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_TIMER2
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_DMA0
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_DMA1
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_DMA2
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_DMA3
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_KEYPAD
bne InterruptMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_GAMEPAK
strbne r0, [r3, OFFSET_REG_SOUNDCNT_X - 0x200]
InterruptMain_Loop:
bne InterruptMain_Loop
InterruptMain_FoundIntr:
strh r0, [r3, OFFSET_REG_IF - 0x200]
bic r2, r2, r0
ldr r0, =gUnknown_03007868
ldr r0, [r0]
ldrb r0, [r0, 0xA]
mov r1, 0x8
mov r0, r1, lsl r0
orr r0, r0, INTR_FLAG_GAMEPAK
orr r1, r0, INTR_FLAG_SERIAL | INTR_FLAG_TIMER3 | INTR_FLAG_VCOUNT | INTR_FLAG_HBLANK
and r1, r1, r2
strh r1, [r3, OFFSET_REG_IE - 0x200]
mrs r3, cpsr
bic r3, r3, PSR_I_BIT | PSR_F_BIT | PSR_MODE_MASK
orr r3, r3, PSR_SYS_MODE
msr cpsr_cf, r3
ldr r1, =gUnknown_03002710
add r1, r1, r12
ldr r0, [r1]
stmdb sp!, {lr}
adr lr, InterruptMain_RetAddr
bx r0
InterruptMain_RetAddr:
ldmia sp!, {lr}
mrs r3, cpsr
bic r3, r3, PSR_I_BIT | PSR_F_BIT | PSR_MODE_MASK
orr r3, r3, PSR_I_BIT | PSR_IRQ_MODE
msr cpsr_cf, r3
ldmia sp!, {r0-r3,lr}
strh r2, [r3, OFFSET_REG_IE - 0x200]
strh r1, [r3, OFFSET_REG_IME - 0x200]
msr spsr_cf, r0
bx lr
.pool
.align 2, 0 @ Don't pad with nop.