mirror of
https://github.com/devkitPro/buildscripts.git
synced 2026-04-25 07:22:27 -05:00
248 lines
9.2 KiB
ArmAsm
248 lines
9.2 KiB
ArmAsm
.section ".init"
|
|
.global _start
|
|
.align
|
|
.arm
|
|
@---------------------------------------------------------------------------------
|
|
_start:
|
|
@---------------------------------------------------------------------------------
|
|
b rom_header_end
|
|
|
|
.fill 156,1,0 @ Nintendo Logo Character Data (8000004h)
|
|
.fill 16,1,0 @ Game Title
|
|
.byte 0x30,0x31 @ Maker Code (80000B0h)
|
|
.byte 0x96 @ Fixed Value (80000B2h)
|
|
.byte 0x00 @ Main Unit Code (80000B3h)
|
|
.byte 0x00 @ Device Type (80000B4h)
|
|
.fill 7,1,0 @ unused
|
|
.byte 0x00 @ Software Version No (80000BCh)
|
|
.byte 0xf0 @ Complement Check (80000BDh)
|
|
.byte 0x00,0x00 @ Checksum (80000BEh)
|
|
|
|
@---------------------------------------------------------------------------------
|
|
rom_header_end:
|
|
@---------------------------------------------------------------------------------
|
|
b start_vector @ This branch must be here for proper
|
|
@ positioning of the following header.
|
|
|
|
.GLOBAL __boot_method, __slave_number
|
|
@---------------------------------------------------------------------------------
|
|
__boot_method:
|
|
@---------------------------------------------------------------------------------
|
|
.byte 0 @ boot method (0=ROM boot, 3=Multiplay boot)
|
|
@---------------------------------------------------------------------------------
|
|
__slave_number:
|
|
@---------------------------------------------------------------------------------
|
|
.byte 0 @ slave # (1=slave#1, 2=slave#2, 3=slave#3)
|
|
|
|
.byte 0 @ reserved
|
|
.byte 0 @ reserved
|
|
.word 0 @ reserved
|
|
.word 0 @ reserved
|
|
.word 0 @ reserved
|
|
.word 0 @ reserved
|
|
.word 0 @ reserved
|
|
.word 0 @ reserved
|
|
|
|
.global start_vector
|
|
.align
|
|
@---------------------------------------------------------------------------------
|
|
start_vector:
|
|
@---------------------------------------------------------------------------------
|
|
mov r0, #0x4000000 @ REG_BASE
|
|
add r0,r0,#0x208 @ REG_IME
|
|
strh r0,[r0]
|
|
|
|
mov r0, #0x12 @ Switch to IRQ Mode
|
|
msr cpsr, r0
|
|
ldr sp,=__sp_irq @ Set IRQ stack
|
|
mov r0, #0x1f @ Switch to System Mode
|
|
msr cpsr, r0
|
|
ldr sp,=__sp_usr @ Set user stack
|
|
|
|
@---------------------------------------------------------------------------------
|
|
@ Enter Thumb mode
|
|
@---------------------------------------------------------------------------------
|
|
add r0,pc,#1
|
|
bx r0
|
|
|
|
.thumb
|
|
|
|
ldr r0,=__text_start
|
|
lsl r0,#5 @ Was code compiled at 0x08000000 or higher?
|
|
bcs DoEWRAMClear @ yes, you can not run it in external WRAM
|
|
|
|
mov r0,pc
|
|
lsl r0,#5 @ Are we running from ROM (0x8000000 or higher) ?
|
|
bcc SkipEWRAMClear @ No, so no need to do a copy.
|
|
|
|
@---------------------------------------------------------------------------------
|
|
@ We were started in ROM, silly emulators. :P
|
|
@ So we need to copy to ExWRAM.
|
|
@---------------------------------------------------------------------------------
|
|
mov r3,#0x40
|
|
lsl r3,#12 @ r3 = 0x40000
|
|
lsl r2,r3,#7 @ r2 = 0x2000000
|
|
mov r6,r2 @ r6 = 0x2000000
|
|
lsl r1,r2,#2 @ r1 = 0x8000000
|
|
|
|
bl CopyMem
|
|
|
|
bx r6 @ Jump to the code to execute
|
|
|
|
@---------------------------------------------------------------------------------
|
|
DoEWRAMClear: @ Clear External WRAM to 0x00
|
|
@---------------------------------------------------------------------------------
|
|
mov r1,#0x40
|
|
lsl r1,#12 @ r1 = 0x40000
|
|
lsl r0,r1,#7 @ r0 = 0x2000000
|
|
bl ClearMem
|
|
|
|
@---------------------------------------------------------------------------------
|
|
SkipEWRAMClear: @ Clear Internal WRAM to 0x00
|
|
@---------------------------------------------------------------------------------
|
|
mov r0,#3
|
|
lsl r0,#24 @ r0 = 0x3000000
|
|
ldr r1,=__sp_usr_offset - 16
|
|
bl ClearMem
|
|
|
|
@---------------------------------------------------------------------------------
|
|
@ Clear BSS section to 0x00
|
|
@---------------------------------------------------------------------------------
|
|
ldr r0,=__sbss_start
|
|
ldr r1,=__sbss_end
|
|
sub r1,r0
|
|
bl ClearMem
|
|
|
|
@---------------------------------------------------------------------------------
|
|
@ Copy initialized data (data section) from LMA to VMA (ROM to RAM)
|
|
@---------------------------------------------------------------------------------
|
|
ldr r1,=__data_lma
|
|
ldr r2,=__data_start
|
|
ldr r4,=__data_end
|
|
bl CopyMemChk
|
|
|
|
@---------------------------------------------------------------------------------
|
|
@ Copy internal work ram (iwram section) from LMA to VMA (ROM to RAM)
|
|
@---------------------------------------------------------------------------------
|
|
ldr r1,=__iwram_lma
|
|
ldr r2,=__iwram_start
|
|
ldr r4,=__iwram_end
|
|
bl CopyMemChk
|
|
|
|
@---------------------------------------------------------------------------------
|
|
@ Copy internal work ram overlay 0 (iwram0 section) from LMA to VMA (ROM to RAM)
|
|
@---------------------------------------------------------------------------------
|
|
ldr r2,=__load_stop_iwram0
|
|
ldr r1,=__load_start_iwram0
|
|
sub r3,r2,r1 @ Is there any data to copy?
|
|
beq CIW0Skip @ no
|
|
|
|
ldr r2,=__iwram_overlay_start
|
|
bl CopyMem
|
|
@---------------------------------------------------------------------------------
|
|
CIW0Skip:
|
|
@---------------------------------------------------------------------------------
|
|
@ Copy external work ram (ewram section) from LMA to VMA (ROM to RAM)
|
|
@---------------------------------------------------------------------------------
|
|
ldr r1,=__ewram_lma
|
|
ldr r2,=__ewram_start
|
|
ldr r4,=__ewram_end
|
|
bl CopyMemChk
|
|
|
|
@---------------------------------------------------------------------------------
|
|
@ Copy external work ram overlay 0 (ewram0 section) from LMA to VMA (ROM to RAM)
|
|
@---------------------------------------------------------------------------------
|
|
ldr r2,=__load_stop_ewram0
|
|
ldr r1,=__load_start_ewram0
|
|
sub r3,r2,r1 @ Is there any data to copy?
|
|
beq CEW0Skip @ no
|
|
|
|
ldr r2,=__ewram_overlay_start
|
|
bl CopyMem
|
|
@---------------------------------------------------------------------------------
|
|
CEW0Skip:
|
|
@---------------------------------------------------------------------------------
|
|
@ set heap end
|
|
@---------------------------------------------------------------------------------
|
|
ldr r1,=fake_heap_end
|
|
ldr r0,=__eheap_end
|
|
str r0,[r1]
|
|
@---------------------------------------------------------------------------------
|
|
@ global constructors
|
|
@---------------------------------------------------------------------------------
|
|
ldr r3,=_init
|
|
bl _call_via_r3
|
|
@---------------------------------------------------------------------------------
|
|
@ Jump to user code
|
|
@---------------------------------------------------------------------------------
|
|
mov r0,#0 @ int argc
|
|
mov r1,#0 @ char *argv[]
|
|
ldr r3,=main
|
|
bl _call_via_r3
|
|
@---------------------------------------------------------------------------------
|
|
@ Clear memory to 0x00 if length != 0
|
|
@---------------------------------------------------------------------------------
|
|
@ r0 = Start Address
|
|
@ r1 = Length
|
|
@---------------------------------------------------------------------------------
|
|
ClearMem:
|
|
@---------------------------------------------------------------------------------
|
|
mov r2,#3 @ These commands are used in cases where
|
|
add r1,r2 @ the length is not a multiple of 4,
|
|
bic r1,r2 @ even though it should be.
|
|
|
|
beq ClearMX @ Length is zero so exit
|
|
|
|
mov r2,#0
|
|
@---------------------------------------------------------------------------------
|
|
ClrLoop:
|
|
@---------------------------------------------------------------------------------
|
|
stmia r0!,{r2}
|
|
sub r1,#4
|
|
bne ClrLoop
|
|
@---------------------------------------------------------------------------------
|
|
ClearMX:
|
|
@---------------------------------------------------------------------------------
|
|
bx lr
|
|
|
|
@---------------------------------------------------------------------------------
|
|
@ Copy memory if length != 0
|
|
@---------------------------------------------------------------------------------
|
|
@ r1 = Source Address
|
|
@ r2 = Dest Address
|
|
@ r4 = Dest Address + Length
|
|
@---------------------------------------------------------------------------------
|
|
CopyMemChk:
|
|
@---------------------------------------------------------------------------------
|
|
sub r3,r4,r2 @ Is there any data to copy?
|
|
@---------------------------------------------------------------------------------
|
|
@ Copy memory
|
|
@---------------------------------------------------------------------------------
|
|
@ r1 = Source Address
|
|
@ r2 = Dest Address
|
|
@ r3 = Length
|
|
@---------------------------------------------------------------------------------
|
|
CopyMem:
|
|
@---------------------------------------------------------------------------------
|
|
mov r0,#3 @ These commands are used in cases where
|
|
add r3,r0 @ the length is not a multiple of 4,
|
|
bic r3,r0 @ even though it should be.
|
|
beq CIDExit @ Length is zero so exit
|
|
|
|
@---------------------------------------------------------------------------------
|
|
CIDLoop:
|
|
@---------------------------------------------------------------------------------
|
|
ldmia r1!,{r0}
|
|
stmia r2!,{r0}
|
|
sub r3,#4
|
|
bne CIDLoop
|
|
@---------------------------------------------------------------------------------
|
|
CIDExit:
|
|
@---------------------------------------------------------------------------------
|
|
bx lr
|
|
|
|
.align
|
|
.pool
|
|
.end
|
|
|