diff options
Diffstat (limited to 'asm')
| -rwxr-xr-x | asm/ewram.s | 6 | ||||
| -rwxr-xr-x | asm/macros.inc | 1 | ||||
| -rwxr-xr-x | asm/macros/label.inc | 4 | ||||
| -rwxr-xr-x | asm/rom.s | 3 | ||||
| -rwxr-xr-x | asm/start.s | 111 |
5 files changed, 123 insertions, 2 deletions
diff --git a/asm/ewram.s b/asm/ewram.s index 2bc030e..0857a08 100755 --- a/asm/ewram.s +++ b/asm/ewram.s @@ -1 +1,7 @@ + .include "asm/macros.inc" + .section ewram + +.space 0x3060 + +ds gIntrTable @ 0x2003060 diff --git a/asm/macros.inc b/asm/macros.inc new file mode 100755 index 0000000..75ebd12 --- /dev/null +++ b/asm/macros.inc @@ -0,0 +1 @@ + .include "asm/macros/label.inc" diff --git a/asm/macros/label.inc b/asm/macros/label.inc new file mode 100755 index 0000000..9812a85 --- /dev/null +++ b/asm/macros/label.inc @@ -0,0 +1,4 @@ + .macro ds name + .global \name + \name\(): + .endm @@ -1,4 +1,3 @@ .text -start: - .incbin "baserom.gba" +.incbin "baserom.gba", 0x23C, 0x7FFDC4 diff --git a/asm/start.s b/asm/start.s new file mode 100755 index 0000000..b23c4c8 --- /dev/null +++ b/asm/start.s @@ -0,0 +1,111 @@ + .include "constants/gba_constants.inc" + + .syntax unified + .arm + +Start: @ 8000000 + b Init + +.incbin "baserom.gba", 0x4, 0xBC + + .arm + .align 2 +Init: @ 80000C0 + mov r0, #0x12 + msr cpsr_cf, r0 + ldr sp, sp_irq + mov r0, #0x1F + msr cpsr_cf, r0 + ldr sp, sp_sys + ldr r1, =INTR_VECTOR + adr r0, IntrMain + str r0, [r1] + ldr r1, =0x800095C + 1 + mov lr, pc + bx r1 + b Init +sp_sys: .4byte IWRAM_END - 0x100 +sp_irq: .4byte IWRAM_END - 0x60 + .pool + +IntrMain: @ 8000104 + mov r3, REG_BASE + add r3, r3, OFFSET_REG_IE + ldr r2, [r3] + ldrh r1, [r3, OFFSET_REG_IME - OFFSET_REG_IE] + mrs r0, spsr + stmdb sp!, {r0-r3,lr} + mov r0, 1 + strh r0, [r3, OFFSET_REG_IME - OFFSET_REG_IE] + and r1, r2, r2, lsr 16 + mov r12, 0 + ands r0, r1, INTR_FLAG_SERIAL + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_TIMER3 + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_VBLANK + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_HBLANK + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_VCOUNT + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_TIMER0 + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_TIMER1 + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_TIMER2 + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_DMA0 + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_DMA1 + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_DMA2 + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_DMA3 + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_KEYPAD + bne IntrMain_FoundIntr + add r12, r12, 4 + ands r0, r1, INTR_FLAG_GAMEPAK + strbne r0, [r3, OFFSET_REG_SOUNDCNT_X - OFFSET_REG_IE] + bne . @ spin +IntrMain_FoundIntr: @ 80001D4 + strh r0, [r3, OFFSET_REG_IF - OFFSET_REG_IE] + mov r1, INTR_FLAG_GAMEPAK | INTR_FLAG_TIMER3 | INTR_FLAG_SERIAL + bic r2, r2, r0 + and r1, r1, r2 + strh r1, [r3] + 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, =gIntrTable + add r1, r1, r12 + ldr r0, [r1] + stmdb sp!, {lr} + adr lr, IntrMain_RetAddr + bx r0 +IntrMain_RetAddr: @ 8000210 + ldmfd 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 + ldmfd sp!, {r0-r3,lr} + strh r2, [r3] + strh r1, [r3, OFFSET_REG_IME - OFFSET_REG_IE] + msr spsr_cf, r0 + bx lr + .pool |