first commit

1 files changed, 227 insertions, 0 deletions

diff --git a/asm/crt0.s b/asm/crt0.s
new file mode 100644
index 000000000..37c7ef502
--- /dev/null
+++ b/asm/crt0.s
@@ -0,0 +1,227 @@
+	.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
+
+	.space 6
+
+@ 80000D0
+
+@ TODO: figure out what this data is
+
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte          4
+	.4byte          2
+	.ascii "pokemon red version"
+	.space 13
+	.4byte  0x82350AC @ gMonFrontPicTable
+	.4byte  0x823654C @ gMonBackPicTable
+	.4byte  0x823730C @ gMonPaletteTable
+	.4byte  0x82380CC @ gMonShinyPaletteTable
+	.4byte  0x83D37A0 @ gMonIconTable
+	.4byte  0x83D3E80 @ gMonIconPaletteIndices
+	.4byte  0x83D4038 @ gMonIconPaletteTable
+	.4byte  0x8245EE0 @ gSpeciesNames
+	.4byte  0x8247094 @ gMoveNames
+	.4byte  0x84556F8 @ gDecorations
+	.4byte      0xEE0
+	.4byte     0x1000
+	.4byte       0x18
+	.4byte      0x5F8
+	.4byte     0x3A18
+	.4byte       0x3C
+	.4byte      0x838
+	.4byte      0x839
+	.4byte      0x182
+	.4byte  0xA0A0A07
+	.4byte  0xC060C0C
+	.4byte  0xC121006
+	.4byte  0x8010B0F
+	.4byte        0xC
+	.4byte      0xF24
+	.4byte     0x3D68
+	.4byte       0x34
+	.4byte       0x38
+	.4byte          9
+	.4byte        0xA
+	.4byte          0
+	.4byte          8
+	.4byte       0xAD
+	.4byte       0xAD
+	.4byte     0x30BB
+	.4byte     0x30A7
+	.4byte          0
+	.4byte  0x8254784
+	.4byte  0x824FC40
+	.4byte  0x824FB08
+	.4byte  0x83DB028
+	.4byte  0x8250C04
+	.4byte  0x826056C
+	.4byte  0x82605CC
+	.4byte       0xA8
+	.4byte      0x82C
+	.4byte      0x83B
+	.4byte 0x3A0D1E2A
+	.4byte     0x1E2B
+	.4byte      0x298
+	.4byte     0x309C
+	.4byte     0x30EC
+	.4byte       0x34
+	.4byte          0
+	.4byte 0xFFFFFFFF
+
+	.arm
+	.align 2, 0
+	.global Init
+Init:
+	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, IntrMain
+	str r0, [r1]
+	ldr r1, =AgbMain
+	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 IntrMain
+IntrMain:
+	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 IntrMain_FoundIntr
+	add r12, r12, 0x4
+	mov r0, 0x1
+	strh r0, [r3, OFFSET_REG_IME - 0x200]
+	ands r0, r1, INTR_FLAG_SERIAL
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_TIMER3
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_HBLANK
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_VBLANK
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_TIMER0
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_TIMER1
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_TIMER2
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_DMA0
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_DMA1
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_DMA2
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_DMA3
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_KEYPAD
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_GAMEPAK
+	strbne r0, [r3, OFFSET_REG_SOUNDCNT_X - 0x200]
+	bne . @ spin
+IntrMain_FoundIntr:
+	strh r0, [r3, OFFSET_REG_IF - 0x200]
+	bic r2, r2, r0
+	ldr r0, =gRfuState
+	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, =gIntrTable
+	add r1, r1, r12
+	ldr r0, [r1]
+	stmdb sp!, {lr}
+	adr lr, IntrMain_RetAddr
+	bx r0
+IntrMain_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.