pmd-red/asm/crt0.s
mid-kid 99a038284b Translate all .include to #include
This decision was made to reduce the complexity of using .include whilst
juggling with tools/scaninc and tools/preproc:
- tools/scaninc doesn't apply the proper search rules for .include (it
  assumes #include behavior). In particular, it doesn't consider paths
  starting from $PWD, and doesn't scan the included files as a result.
- .include had to be processed before #include by preproc in many cases,
  as code was being included that had to be preprocessed by CPP (think
  of #define). This contradicts standard GCC behavior.

To make include paths consistent across the asm/ data/ and src/
directories, the following files were moved:
- constants/ → include/asm/constants/
- asm/macros/ → include/asm/macros/
- asm/macros.inc → include/asm/macros.inc
- include/macros/m4a.inc → include/asm/macros/m4a.inc

As part of the necessary changes for this to work, the scaninc method in
the makefile was improved to generate .d files that don't choke when
files are missing.
2021-12-20 16:29:12 +01:00

104 lines
1.9 KiB
ArmAsm

#include "asm/constants/gba_constants.inc"
.syntax unified
.global Start
.text
.arm
Start: @ 8000000
b Init
#include "rom_header.inc"
.arm
.align 2, 0
.global Init
Init: @ 80000C0
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 - 0x100
sp_irq: .word IWRAM_END - 0x60
.pool
.arm
.align 2, 0
.global IntrMain
IntrMain: @ 8000104
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, 1
strh r0, [r3, OFFSET_REG_IME - 0x200]
and r1, r2, r2, lsr 16
mov r12, 0
ands r0, r1, INTR_FLAG_SERIAL | INTR_FLAG_TIMER3
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_VCOUNT
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_TIMER3
bne IntrMain_FoundIntr
add r12, r12, 0x4
ands r0, r1, INTR_FLAG_GAMEPAK
strbne r0, [r3, OFFSET_REG_SOUNDCNT_X - 0x200]
IntrMain_Loop:
bne IntrMain_Loop
IntrMain_FoundIntr:
strh r0, [r3, OFFSET_REG_IF - 0x200]
mov r1, INTR_FLAG_GAMEPAK | INTR_FLAG_SERIAL
bic r2, r2, r0
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.