melonDS/freebios/bios_common.S
CasualPokePlayer 1b7b5106e2 FreeBIOS: Ensure upper 16 bits are cleared in the initial crc16 value.
Fixes Castlevania: Dawn of Sorrow's checksumming which uses crc16 swi and has garbage in the upper 16 bits of r0.
The official BIOS would seem to implicitly clear these upper 16 bits.
2023-12-06 16:51:22 +01:00

1207 lines
35 KiB
ArmAsm
Executable File

# Custom NDS ARM7/ARM9 BIOS replacement
# Copyright (c) 2013, Gilead Kutnick
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1) Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# 2) Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
.section .text
.org 0x00000000
// Vector table
b boot_handler // 0x00 Reset
b unhandled_exception // 0x04 Undefined
b swi_handler // 0x08 SWI
b unhandled_exception // 0x0C Abort Prefetch
b unhandled_exception // 0x10 Abort Data
b unhandled_exception // 0x14 Reserved
b interrupt_handler // 0x18 IRQ
b unhandled_exception // 0x1C FIQ
#ifdef BIOS_ARM9
// ARM9 BIOS has a logo here (0x9C bytes), we don't want to include the logo
// but we'll leave a space for it.
.fill 0xe0, 0x1, 0x0
#endif
#ifdef BIOS_ARM7
// ARM7 BIOS has encryption stuff at 0x30, we don't want to include it but we'll
// leave a space for it.
.fill 0x1058, 0x1, 0x0
#endif
// TODO: This needs to be implemented. Not needed for emulators that HLE bootup.
boot_handler:
0:
b 0b
// Not sure what this should do, it's probably best to be pretty visible though.
unhandled_exception:
0:
b 0b
#ifdef BIOS_ARM7
#define swi_label(function) .word function
#define swi_label_arm7_only(function) swi_label(function)
#else
#define swi_label_arm7_only(function) swi_label(swi_invalid)
#endif
#ifdef BIOS_ARM9
#define swi_label(function) .word (function + 0xFFFF0000)
#define swi_label_arm9_only(function) swi_label(function)
#else
#define swi_label_arm9_only(function) swi_label(swi_invalid)
#endif
// SWI calling convention:
// Parameters are passed in via r0 - r3
// Called SWI can modify r0 - r3 (and return things here) and r4, r12, and r14.
// They can't modify anything else.
#define swi_comment r12
#define saved_spsr r4
#define modified_spsr r4
swi_handler:
// Save these as temporaries
stmdb sp!, { r4, r12, lr }
// get SPSR and enter system mode, interrupts on
mrs saved_spsr, SPSR
// This must be stacked and not just saved, because otherwise SWI won't
// be reentrant, which can happen if you're waiting for interrupts and the
// interrupt handler triggers the SWI.
stmdb sp!, { saved_spsr }
and modified_spsr, saved_spsr, #0x80
orr modified_spsr, modified_spsr, #0x1F
// Load comment from SWI instruction, which indicates which SWI
// to use.
ldrb swi_comment, [ lr, #-2 ]
msr CPSR_fc, modified_spsr
// We have to now save system-mode lr register as well
stmdb sp!, { lr }
// Not sure if this should be here or not, but it probably doesn't
// hurt, and is better than flooding the table with 256 entries..
// This will move in the known entry of an invalid SWI.
cmp swi_comment, #0x20
movge swi_comment, #0x01
// Branch to SWI handler
ldr pc, [ pc, swi_comment, lsl #2 ]
nop
// SWI table begins here
// If there's no entry just go straight to swi_complete
swi_label(swi_soft_reset) // 00
swi_label(swi_invalid) // 01
swi_label(swi_invalid) // 02
swi_label(swi_wait_by_loop) // 03
swi_label(swi_interrupt_wait) // 04
swi_label(swi_vblank_interrupt_wait) // 05
swi_label(swi_halt) // 06
swi_label_arm7_only(swi_stop) // 07
swi_label_arm7_only(swi_sound_bias) // 08
swi_label(swi_divide) // 09
swi_label(swi_invalid) // 0A
swi_label(swi_cpu_set) // 0B
swi_label(swi_cpu_fast_set) // 0C
swi_label(swi_sqrt) // 0D
swi_label(swi_get_crc16) // 0E
swi_label(swi_is_debugger) // 0F
swi_label(swi_bit_unpack) // 10
swi_label(swi_lz77_decompress_wram) // 11
swi_label(swi_lz77_decompress_vram) // 12
swi_label(swi_huffman_decompress) // 13
swi_label(swi_runlength_decompress_wram) // 14
swi_label(swi_runlength_decompress_vram) // 15
swi_label_arm9_only(swi_diff_8bit_unfilter_wram) // 16
swi_label(swi_invalid) // 17
swi_label_arm9_only(swi_diff_16bit_unfilter) // 18
swi_label(swi_invalid) // 19
swi_label_arm7_only(swi_get_sine_table) // 1A
swi_label_arm7_only(swi_get_pitch_table) // 1B
swi_label_arm7_only(swi_get_volume_table) // 1C
swi_label_arm7_only(swi_get_boot_procs) // 1D
swi_label(swi_custom_halt_post) // 1F
swi_invalid:
// This just passes through to completion.
// SWI returns here
swi_complete:
// Restore system mode lr
ldmia sp!, { lr }
// Go back to supervisor mode to get back to that stack
mov modified_spsr, #0xD3
msr CPSR_fc, modified_spsr
// SPSR has to be restored because the transition to system mode broke it
ldmia sp!, { saved_spsr }
msr SPSR, saved_spsr
// Restore stuff we saved
ldmia sp!, { r4, r12, lr }
// Return from exception handler
movs pc, lr
padding_a:
.word 0x0
swi_halt:
#ifdef BIOS_ARM7
mov r0, #0x04000000
mov r2, #0x80
strb r2, [ r0, #0x301 ]
#else
mov r0, #0x0
mcr p15, 0, r0, cr7, cr0, 4
#endif
b swi_complete
swi_wait_by_loop:
0:
subs r0, r0, #1
bgt 0b
b swi_complete
#define check_immediately r0
#define irq_wait_mask r1
#ifdef BIOS_ARM7
#define irq_flag_base r3
#else
#define irq_flag_base r2
#endif
#define io_base r3
#define const_0x1 r12
#define irq_flags r0
interrupt_check:
#ifdef BIOS_ARM9
// Get DTCM base
mrc p15, 0, irq_flag_base, cr9, cr1, 0
bic irq_flag_base, irq_flag_base, #0xFF
// Software IRQ flag is at DTCM[0x3FF8]
add irq_flag_base, irq_flag_base, #0x4000
#endif
// Load software IRQ flag
ldr irq_flags, [ irq_flag_base, #-8 ]
// Set IME (0x04000208) to 0
str io_base, [ io_base, #0x208 ]
// Check if IRQs were risen, to see if the loop can exit
tst irq_wait_mask, irq_flags
// Clear IRQs that were risen and write back
bic irq_flags, irq_flags, irq_wait_mask
str irq_flags, [ irq_flag_base, #-8 ]
mov const_0x1, #0x1
// Set IME (0x04000208) to 1 and return
str const_0x1, [ io_base, #0x208 ]
bx lr
#define halt_value r0
swi_vblank_interrupt_wait:
// Check immediately for VBLANK interrupt
mov check_immediately, #1
mov irq_wait_mask, #1
// Fall through
swi_interrupt_wait:
mov io_base, #0x4000000
// See if we should return immediately or halt
cmp check_immediately, #0
blne interrupt_check
// Perform this loop until the interrupt is risen
0:
#ifdef BIOS_ARM9
// Halt ARM9 via coprocessor instruction
mov halt_value, #0
mcr p15, 0, halt_value, cr7, cr0, 4
#else
mov halt_value, #0x80
// Set HALTCNT to 0x80
strb halt_value, [ io_base, #0x301 ]
#endif
bl interrupt_check
beq 0b
b swi_complete
swi_interrupt_check_first:
// Check for IRQ
bl interrupt_check
// If set exit.
bne swi_complete
// If not wait for interrupt.
b 0b
#ifdef BIOS_ARM7
swi_stop:
mov r0, #0x04000000
mov r1, #0xC0
strb r1, [ r0, #0x301 ]
b swi_complete
#define bias_ptr r0
#define bias_value r1
swi_sound_bias:
mov bias_ptr, #0x4000000
add bias_ptr, bias_ptr, #0x500
ldr bias_value, [ bias_ptr, #0x4 ]
cmp bias_value, #0
movne bias_value, #0x200
str bias_value, [ bias_ptr, #0x4 ]
// TODO: Needs to add delay
b swi_complete
#endif
#define numerator r0
#define denominator r1
#define accumulator r2
#define current_bit r3
#define numerator_signed r12
#define denominator_signed r3
#define sign_flip r12
#define result r0
#define remainder r1
#define result_abs r3
swi_divide:
// Set if numerator is signed, and abs numerator
ands numerator_signed, numerator, #0x80000000
rsbmi numerator, numerator, #0
// Same with denominator
ands denominator_signed, denominator, #0x80000000
rsbmi denominator, denominator, #0
// Gets set if sign(numerator) != sign(denominator)
eor sign_flip, numerator_signed, denominator_signed
mov accumulator, #0
mov current_bit, #1
// This moves out the current bit to the MSB of the denominator,
// and aligns the denominator up to the same bit-length as the
// numerator
0:
cmp denominator, numerator
movls denominator, denominator, lsl #1
movls current_bit, current_bit, lsl #1
bls 0b
// Basically the grade-school algorithm, for unsigned integers in binary
1:
cmp numerator, denominator
subcs numerator, numerator, denominator
orrcs accumulator, accumulator, current_bit
movs current_bit, current_bit, lsr #1
movcc denominator, denominator, lsr #1
bcc 1b
mov remainder, numerator
mov result_abs, accumulator
mov result, accumulator
tst sign_flip, #0x80000000
rsbmi result, result, #0
b swi_complete
#define source r0
#define dest r1
#define copy_control r2
#define value r3
#define length r12
swi_cpu_set:
// Only take 21 bits for length.
bic length, copy_control, #0xFF000000
bic length, length, #0x00E00000
tst copy_control, #(1 << 26)
bne copy_32bit
copy_16bit:
tst copy_control, #(1 << 24)
bic source, #0x1
bic dest, #0x1
bne set_16bit
0:
ldrh value, [ source ], #2
subs length, length, #1
strh value, [ dest ], #2
bne 0b
b swi_complete
set_16bit:
ldrh value, [ source ]
0:
strh value, [ dest ], #2
subs length, length, #1
bne 0b
b swi_complete
copy_32bit:
tst copy_control, #(1 << 24)
bic source, #0x3
bic dest, #0x3
bne set_32bit
0:
ldr value, [ source ], #4
subs length, length, #1
str value, [ dest ], #4
bne 0b
b swi_complete
set_32bit:
ldr value, [ source ]
0:
str value, [ dest ], #4
subs length, length, #1
bne 0b
b swi_complete
// TODO: Make this actually faster (ldm/stm)
swi_cpu_fast_set:
// Only take 21 bits for length.
bic length, copy_control, #0xFF000000
bic length, length, #0x00E00000
tst copy_control, #(1 << 24)
bic source, #0x3
bic dest, #0x3
bne fast_set_32bit
0:
ldr value, [ source ], #4
subs length, length, #1
str value, [ dest ], #4
bne 0b
b swi_complete
fast_set_32bit:
ldr value, [ source ]
0:
str value, [ dest ], #4
subs length, length, #1
bne 0b
b swi_complete
#undef remainder
#define sqrt_value r0
#define remainder r0
#define result r0
#define square_index r1
#define root r2
#define root_check r3
swi_sqrt:
mov square_index, #0x40000000
mov root, #0x0
0:
orr root_check, square_index, root
cmp remainder, root_check
subge remainder, remainder, root_check
mov root, root, lsr #1
orrge root, root, square_index
movs square_index, square_index, lsr #2
bne 0b
mov result, root
b swi_complete
#undef current_value
#define crc_value r0
#define crc_ptr r1
#define crc_length r2
#define current_value r3
#define const_0x1E r4
#define crc_index r5
#define crc_table_ptr r14
#define crc_lookup r12
#define crc_nibble(shift) ;\
and crc_index, const_0x1E, crc_value, lsl #1 ;\
ldrh crc_lookup, [ crc_table_ptr, crc_index ] ;\
mov crc_value, crc_value, lsr #4 ;\
eor crc_value, crc_value, crc_lookup ;\
;\
and crc_index, const_0x1E, current_value, shift ;\
ldrh crc_lookup, [ crc_table_ptr, crc_index ] ;\
eor crc_value, crc_value, crc_lookup ;\
crc_table:
.hword 0x0000, 0xCC01, 0xD801, 0x1400, 0xF001, 0x3C00, 0x2800, 0xE401
.hword 0xA001, 0x6C00, 0x7800, 0xB401, 0x5000, 0x9C01, 0x8801, 0x4400
swi_get_crc16:
stmdb sp!, { r5 }
mov const_0x1E, #0x1E
adr crc_table_ptr, crc_table
bic crc_value, crc_value, #0xFF000000
bic crc_value, crc_value, #0x00FF0000
movs crc_length, crc_length, lsr #1
beq 1f
0:
ldrh current_value, [ crc_ptr ], #2
crc_nibble(lsl #1)
crc_nibble(lsr #3)
crc_nibble(lsr #7)
crc_nibble(lsr #11)
subs crc_length, crc_length, #1
bne 0b
1:
ldmia sp!, { r5 }
b swi_complete
swi_is_debugger:
mov r0, #0
b swi_complete
#undef length
#define source r0
#define dest r1
#define unpack_data r2
#define length r3
#define source_bit_width r12
#define dest_bit_width r14
#define data_offset r4
#define offset_zero r2
#define source_mask r5
#define source_bit_buffer r6
#define dest_bit_buffer r7
#define dest_bits_loaded r8
#define source_value r9
swi_bit_unpack:
stmdb sp!, { r5 - r9 }
ldrh length, [ unpack_data, #0 ]
ldrb source_bit_width, [ unpack_data, #2 ]
ldrb dest_bit_width, [ unpack_data, #3 ]
ldr data_offset, [ unpack_data, #4 ]
// TODO: Check that bits are <= 32 and a power of 2?
mov offset_zero, data_offset, lsr #31
bic data_offset, data_offset, #0x80000000
mov source_mask, #0x1
mov source_mask, source_mask, lsl source_bit_width
sub source_mask, source_mask, #1
mov source_bit_buffer, #0x1
mov dest_bit_buffer, #0
mov dest_bits_loaded, #0
cmp source_bit_width, #1
moveq length, length, lsl #3
cmp source_bit_width, #2
moveq length, length, lsl #2
cmp source_bit_width, #4
moveq length, length, lsl #1
0:
// Reload bit buffer if necessary
cmp source_bit_buffer, #0x1
ldreqb source_bit_buffer, [ source ], #1
orreq source_bit_buffer, source_bit_buffer, #0x100
// Get next from source
and source_value, source_bit_buffer, source_mask
mov source_bit_buffer, source_bit_buffer, lsr source_bit_width
cmp source_value, #0
tsteq offset_zero, #0x1
addne source_value, source_value, data_offset
// Put it on dest buffer
orr dest_bit_buffer, dest_bit_buffer, source_value, lsl dest_bits_loaded
add dest_bits_loaded, dest_bits_loaded, dest_bit_width
// If dest buffer is full write out
cmp dest_bits_loaded, #32
streq dest_bit_buffer, [ dest ], #4
moveq dest_bit_buffer, #0
moveq dest_bits_loaded, #0
subs length, length, #1
bne 0b
ldmia sp!, { r5 - r9 }
b swi_complete
#undef length
#define source r0
#define dest r1
#define length r2
#define header r3
#define lz77_control r3
#define lz77_value r4
#define lz77_vram_tmp r5
#define lz77_value_b r14
#define window_length r14
#define window_offset r12
#define window_ptr r12
swi_lz77_decompress_wram:
ldr header, [ source ], #4
movs length, header, lsr #8
beq swi_complete
0:
ldrb lz77_control, [ source ], #1
// This will hit the MSB after 8 iterations
orr lz77_control, lz77_control, #(1 << 23)
1:
tst lz77_control, #0x80
beq 2f
// Load a window of data that was loaded before
// Read 16-bit unaligned value
ldrb lz77_value, [ source ], #1
ldrb lz77_value_b, [ source ], #1
orr lz77_value, lz77_value_b, lz77_value, lsl #8
// Get length and offset from lz77 value
mov window_length, lz77_value, lsr #12
bic window_offset, lz77_value, #0xF000
add window_length, window_length, #3
sub window_ptr, dest, window_offset
sub window_ptr, window_ptr, #1
3:
ldrb lz77_value, [ window_ptr ], #1
subs length, length, #1
strb lz77_value, [ dest ], #1
beq swi_complete
subs window_length, window_length, #1
bne 3b
movs lz77_control, lz77_control, lsl #1
bpl 1b
b 0b
// Load a single value
2:
ldrb lz77_value, [ source ], #1
subs length, length, #1
strb lz77_value, [ dest ], #1
beq swi_complete
movs lz77_control, lz77_control, lsl #1
bpl 1b
b 0b
swi_lz77_decompress_vram:
ldr header, [ source ], #4
movs length, header, lsr #8
beq swi_complete
stmdb sp!, { r5 }
mov r5, #0
0:
ldrb lz77_control, [ source ], #1
// This will hit the MSB after 8 iterations
orr lz77_control, lz77_control, #(1 << 23)
1:
tst lz77_control, #0x80
beq 2f
// Load a window of data that was loaded before
// Read 16-bit unaligned value
ldrb lz77_value, [ source ], #1
ldrb lz77_value_b, [ source ], #1
orr lz77_value, lz77_value_b, lz77_value, lsl #8
// Get length and offset from lz77 value
mov window_length, lz77_value, lsr #12
bic window_offset, lz77_value, #0xF000
add window_length, window_length, #3
sub window_ptr, dest, window_offset
sub window_ptr, window_ptr, #1
3:
tst dest, #1
ldreqb lz77_vram_tmp, [ window_ptr ], #1
ldrneb lz77_value, [ window_ptr ], #1
orrne lz77_value, lz77_vram_tmp, lz77_value, lsl #8
strneh lz77_value, [ dest, #-1 ]
add dest, dest, #1
subs length, length, #1
ldmeqia sp!, { r5 }
beq swi_complete
subs window_length, window_length, #1
bne 3b
movs lz77_control, lz77_control, lsl #1
bpl 1b
b 0b
// Load a single value
2:
tst dest, #1
ldreqb lz77_vram_tmp, [ source ], #1
ldrneb lz77_value, [ source ], #1
orrne lz77_value, lz77_vram_tmp, lz77_value, lsl #8
strneh lz77_value, [ dest, #-1 ]
add dest, dest, #1
subs length, length, #1
ldmeqia sp!, { r5 }
beq swi_complete
movs lz77_control, lz77_control, lsl #1
bpl 1b
b 0b
// TODO: Needs to be implemented
swi_huffman_decompress:
b swi_complete
#define source r0
#define dest r1
#define length r2
#define header r3
#define rle_control r3
#define run_length r3
#define rle_value r12
// TODO: Make a safe one for VRAM.
swi_runlength_decompress_vram:
swi_runlength_decompress_wram:
ldr header, [ source ], #4
mov length, header, lsr #8
0:
ldrb rle_control, [ source ], #1
tst rle_control, #0x80
and run_length, rle_control, #0x7F
beq 1f
ldrb rle_value, [ source ], #1
add run_length, run_length, #3
2:
strb rle_value, [ dest ], #1
subs length, length, #1
beq swi_complete
subs run_length, run_length, #1
bne 2b
b 0b
1:
add run_length, run_length, #1
2:
ldrb rle_value, [ source ], #1
subs length, length, #1
strb rle_value, [ dest ], #1
beq swi_complete
subs run_length, run_length, #1
bne 2b
b 0b
#ifdef BIOS_ARM9
#undef accumulator
#undef length
#define source r0
#define dest r1
#define length r2
#define header r3
#define accumulator r12
#define current_value r3
swi_diff_8bit_unfilter_wram:
ldr header, [ source ], #4
ldrb accumulator, [ source ], #1
mov length, header, lsr #8
strb accumulator, [ dest ], #1
sub length, length, #1
0:
ldrb current_value, [ source ], #1
subs length, length, #1
add accumulator, accumulator, current_value
strb accumulator, [ dest ], #1
bne 0b
b swi_complete
swi_diff_16bit_unfilter:
ldr header, [ source ], #4
ldrh accumulator, [ source ], #2
mov length, header, lsr #8
strh accumulator, [ dest ], #2
bic length, length, #0x1
sub length, length, #2
0:
ldrh current_value, [ source ], #2
subs length, length, #2
add accumulator, accumulator, current_value
strh accumulator, [ dest ], #2
bne 0b
b swi_complete
#endif
#ifdef BIOS_ARM7
sine_table:
.hword 0x0000, 0x0324, 0x0648, 0x096A, 0x0C8C, 0x0FAB, 0x12C8, 0x15E2
.hword 0x18F9, 0x1C0B, 0x1F1A, 0x2223, 0x2528, 0x2826, 0x2B1F, 0x2E11
.hword 0x30FB, 0x33DF, 0x36BA, 0x398C, 0x3C56, 0x3F17, 0x41CE, 0x447A
.hword 0x471C, 0x49B4, 0x4C3F, 0x4EBF, 0x5133, 0x539B, 0x55F5, 0x5842
.hword 0x5A82, 0x5CB3, 0x5ED7, 0x60EB, 0x62F1, 0x64E8, 0x66CF, 0x68A6
.hword 0x6A6D, 0x6C23, 0x6DC9, 0x6F5E, 0x70E2, 0x7254, 0x73B5, 0x7504
.hword 0x7641, 0x776B, 0x7884, 0x7989, 0x7A7C, 0x7B5C, 0x7C29, 0x7CE3
.hword 0x7D89, 0x7E1D, 0x7E9C, 0x7F09, 0x7F61, 0x7FA6, 0x7FD8, 0x7FF5
swi_get_sine_table:
add r0, r0, r0
adr r1, sine_table
// Should some protection be here?
ldrh r0, [ r1, r0 ]
b swi_complete
pitch_table:
.hword 0x0000, 0x003B, 0x0076, 0x00B2, 0x00ED, 0x0128, 0x0164, 0x019F
.hword 0x01DB, 0x0217, 0x0252, 0x028E, 0x02CA, 0x0305, 0x0341, 0x037D
.hword 0x03B9, 0x03F5, 0x0431, 0x046E, 0x04AA, 0x04E6, 0x0522, 0x055F
.hword 0x059B, 0x05D8, 0x0614, 0x0651, 0x068D, 0x06CA, 0x0707, 0x0743
.hword 0x0780, 0x07BD, 0x07FA, 0x0837, 0x0874, 0x08B1, 0x08EF, 0x092C
.hword 0x0969, 0x09A7, 0x09E4, 0x0A21, 0x0A5F, 0x0A9C, 0x0ADA, 0x0B18
.hword 0x0B56, 0x0B93, 0x0BD1, 0x0C0F, 0x0C4D, 0x0C8B, 0x0CC9, 0x0D07
.hword 0x0D45, 0x0D84, 0x0DC2, 0x0E00, 0x0E3F, 0x0E7D, 0x0EBC, 0x0EFA
.hword 0x0F39, 0x0F78, 0x0FB6, 0x0FF5, 0x1034, 0x1073, 0x10B2, 0x10F1
.hword 0x1130, 0x116F, 0x11AE, 0x11EE, 0x122D, 0x126C, 0x12AC, 0x12EB
.hword 0x132B, 0x136B, 0x13AA, 0x13EA, 0x142A, 0x146A, 0x14A9, 0x14E9
.hword 0x1529, 0x1569, 0x15AA, 0x15EA, 0x162A, 0x166A, 0x16AB, 0x16EB
.hword 0x172C, 0x176C, 0x17AD, 0x17ED, 0x182E, 0x186F, 0x18B0, 0x18F0
.hword 0x1931, 0x1972, 0x19B3, 0x19F5, 0x1A36, 0x1A77, 0x1AB8, 0x1AFA
.hword 0x1B3B, 0x1B7D, 0x1BBE, 0x1C00, 0x1C41, 0x1C83, 0x1CC5, 0x1D07
.hword 0x1D48, 0x1D8A, 0x1DCC, 0x1E0E, 0x1E51, 0x1E93, 0x1ED5, 0x1F17
.hword 0x1F5A, 0x1F9C, 0x1FDF, 0x2021, 0x2064, 0x20A6, 0x20E9, 0x212C
.hword 0x216F, 0x21B2, 0x21F5, 0x2238, 0x227B, 0x22BE, 0x2301, 0x2344
.hword 0x2388, 0x23CB, 0x240E, 0x2452, 0x2496, 0x24D9, 0x251D, 0x2561
.hword 0x25A4, 0x25E8, 0x262C, 0x2670, 0x26B4, 0x26F8, 0x273D, 0x2781
.hword 0x27C5, 0x280A, 0x284E, 0x2892, 0x28D7, 0x291C, 0x2960, 0x29A5
.hword 0x29EA, 0x2A2F, 0x2A74, 0x2AB9, 0x2AFE, 0x2B43, 0x2B88, 0x2BCD
.hword 0x2C13, 0x2C58, 0x2C9D, 0x2CE3, 0x2D28, 0x2D6E, 0x2DB4, 0x2DF9
.hword 0x2E3F, 0x2E85, 0x2ECB, 0x2F11, 0x2F57, 0x2F9D, 0x2FE3, 0x302A
.hword 0x3070, 0x30B6, 0x30FD, 0x3143, 0x318A, 0x31D0, 0x3217, 0x325E
.hword 0x32A5, 0x32EC, 0x3332, 0x3379, 0x33C1, 0x3408, 0x344F, 0x3496
.hword 0x34DD, 0x3525, 0x356C, 0x35B4, 0x35FB, 0x3643, 0x368B, 0x36D3
.hword 0x371A, 0x3762, 0x37AA, 0x37F2, 0x383A, 0x3883, 0x38CB, 0x3913
.hword 0x395C, 0x39A4, 0x39ED, 0x3A35, 0x3A7E, 0x3AC6, 0x3B0F, 0x3B58
.hword 0x3BA1, 0x3BEA, 0x3C33, 0x3C7C, 0x3CC5, 0x3D0E, 0x3D58, 0x3DA1
.hword 0x3DEA, 0x3E34, 0x3E7D, 0x3EC7, 0x3F11, 0x3F5A, 0x3FA4, 0x3FEE
.hword 0x4038, 0x4082, 0x40CC, 0x4116, 0x4161, 0x41AB, 0x41F5, 0x4240
.hword 0x428A, 0x42D5, 0x431F, 0x436A, 0x43B5, 0x4400, 0x444B, 0x4495
.hword 0x44E1, 0x452C, 0x4577, 0x45C2, 0x460D, 0x4659, 0x46A4, 0x46F0
.hword 0x473B, 0x4787, 0x47D3, 0x481E, 0x486A, 0x48B6, 0x4902, 0x494E
.hword 0x499A, 0x49E6, 0x4A33, 0x4A7F, 0x4ACB, 0x4B18, 0x4B64, 0x4BB1
.hword 0x4BFE, 0x4C4A, 0x4C97, 0x4CE4, 0x4D31, 0x4D7E, 0x4DCB, 0x4E18
.hword 0x4E66, 0x4EB3, 0x4F00, 0x4F4E, 0x4F9B, 0x4FE9, 0x5036, 0x5084
.hword 0x50D2, 0x5120, 0x516E, 0x51BC, 0x520A, 0x5258, 0x52A6, 0x52F4
.hword 0x5343, 0x5391, 0x53E0, 0x542E, 0x547D, 0x54CC, 0x551A, 0x5569
.hword 0x55B8, 0x5607, 0x5656, 0x56A5, 0x56F4, 0x5744, 0x5793, 0x57E2
.hword 0x5832, 0x5882, 0x58D1, 0x5921, 0x5971, 0x59C1, 0x5A10, 0x5A60
.hword 0x5AB0, 0x5B01, 0x5B51, 0x5BA1, 0x5BF1, 0x5C42, 0x5C92, 0x5CE3
.hword 0x5D34, 0x5D84, 0x5DD5, 0x5E26, 0x5E77, 0x5EC8, 0x5F19, 0x5F6A
.hword 0x5FBB, 0x600D, 0x605E, 0x60B0, 0x6101, 0x6153, 0x61A4, 0x61F6
.hword 0x6248, 0x629A, 0x62EC, 0x633E, 0x6390, 0x63E2, 0x6434, 0x6487
.hword 0x64D9, 0x652C, 0x657E, 0x65D1, 0x6624, 0x6676, 0x66C9, 0x671C
.hword 0x676F, 0x67C2, 0x6815, 0x6869, 0x68BC, 0x690F, 0x6963, 0x69B6
.hword 0x6A0A, 0x6A5E, 0x6AB1, 0x6B05, 0x6B59, 0x6BAD, 0x6C01, 0x6C55
.hword 0x6CAA, 0x6CFE, 0x6D52, 0x6DA7, 0x6DFB, 0x6E50, 0x6EA4, 0x6EF9
.hword 0x6F4E, 0x6FA3, 0x6FF8, 0x704D, 0x70A2, 0x70F7, 0x714D, 0x71A2
.hword 0x71F7, 0x724D, 0x72A2, 0x72F8, 0x734E, 0x73A4, 0x73FA, 0x7450
.hword 0x74A6, 0x74FC, 0x7552, 0x75A8, 0x75FF, 0x7655, 0x76AC, 0x7702
.hword 0x7759, 0x77B0, 0x7807, 0x785E, 0x78B4, 0x790C, 0x7963, 0x79BA
.hword 0x7A11, 0x7A69, 0x7AC0, 0x7B18, 0x7B6F, 0x7BC7, 0x7C1F, 0x7C77
.hword 0x7CCF, 0x7D27, 0x7D7F, 0x7DD7, 0x7E2F, 0x7E88, 0x7EE0, 0x7F38
.hword 0x7F91, 0x7FEA, 0x8042, 0x809B, 0x80F4, 0x814D, 0x81A6, 0x81FF
.hword 0x8259, 0x82B2, 0x830B, 0x8365, 0x83BE, 0x8418, 0x8472, 0x84CB
.hword 0x8525, 0x857F, 0x85D9, 0x8633, 0x868E, 0x86E8, 0x8742, 0x879D
.hword 0x87F7, 0x8852, 0x88AC, 0x8907, 0x8962, 0x89BD, 0x8A18, 0x8A73
.hword 0x8ACE, 0x8B2A, 0x8B85, 0x8BE0, 0x8C3C, 0x8C97, 0x8CF3, 0x8D4F
.hword 0x8DAB, 0x8E07, 0x8E63, 0x8EBF, 0x8F1B, 0x8F77, 0x8FD4, 0x9030
.hword 0x908C, 0x90E9, 0x9146, 0x91A2, 0x91FF, 0x925C, 0x92B9, 0x9316
.hword 0x9373, 0x93D1, 0x942E, 0x948C, 0x94E9, 0x9547, 0x95A4, 0x9602
.hword 0x9660, 0x96BE, 0x971C, 0x977A, 0x97D8, 0x9836, 0x9895, 0x98F3
.hword 0x9952, 0x99B0, 0x9A0F, 0x9A6E, 0x9ACD, 0x9B2C, 0x9B8B, 0x9BEA
.hword 0x9C49, 0x9CA8, 0x9D08, 0x9D67, 0x9DC7, 0x9E26, 0x9E86, 0x9EE6
.hword 0x9F46, 0x9FA6, 0xA006, 0xA066, 0xA0C6, 0xA127, 0xA187, 0xA1E8
.hword 0xA248, 0xA2A9, 0xA30A, 0xA36B, 0xA3CC, 0xA42D, 0xA48E, 0xA4EF
.hword 0xA550, 0xA5B2, 0xA613, 0xA675, 0xA6D6, 0xA738, 0xA79A, 0xA7FC
.hword 0xA85E, 0xA8C0, 0xA922, 0xA984, 0xA9E7, 0xAA49, 0xAAAC, 0xAB0E
.hword 0xAB71, 0xABD4, 0xAC37, 0xAC9A, 0xACFD, 0xAD60, 0xADC3, 0xAE27
.hword 0xAE8A, 0xAEED, 0xAF51, 0xAFB5, 0xB019, 0xB07C, 0xB0E0, 0xB145
.hword 0xB1A9, 0xB20D, 0xB271, 0xB2D6, 0xB33A, 0xB39F, 0xB403, 0xB468
.hword 0xB4CD, 0xB532, 0xB597, 0xB5FC, 0xB662, 0xB6C7, 0xB72C, 0xB792
.hword 0xB7F7, 0xB85D, 0xB8C3, 0xB929, 0xB98F, 0xB9F5, 0xBA5B, 0xBAC1
.hword 0xBB28, 0xBB8E, 0xBBF5, 0xBC5B, 0xBCC2, 0xBD29, 0xBD90, 0xBDF7
.hword 0xBE5E, 0xBEC5, 0xBF2C, 0xBF94, 0xBFFB, 0xC063, 0xC0CA, 0xC132
.hword 0xC19A, 0xC202, 0xC26A, 0xC2D2, 0xC33A, 0xC3A2, 0xC40B, 0xC473
.hword 0xC4DC, 0xC544, 0xC5AD, 0xC616, 0xC67F, 0xC6E8, 0xC751, 0xC7BB
.hword 0xC824, 0xC88D, 0xC8F7, 0xC960, 0xC9CA, 0xCA34, 0xCA9E, 0xCB08
.hword 0xCB72, 0xCBDC, 0xCC47, 0xCCB1, 0xCD1B, 0xCD86, 0xCDF1, 0xCE5B
.hword 0xCEC6, 0xCF31, 0xCF9C, 0xD008, 0xD073, 0xD0DE, 0xD14A, 0xD1B5
.hword 0xD221, 0xD28D, 0xD2F8, 0xD364, 0xD3D0, 0xD43D, 0xD4A9, 0xD515
.hword 0xD582, 0xD5EE, 0xD65B, 0xD6C7, 0xD734, 0xD7A1, 0xD80E, 0xD87B
.hword 0xD8E9, 0xD956, 0xD9C3, 0xDA31, 0xDA9E, 0xDB0C, 0xDB7A, 0xDBE8
.hword 0xDC56, 0xDCC4, 0xDD32, 0xDDA0, 0xDE0F, 0xDE7D, 0xDEEC, 0xDF5B
.hword 0xDFC9, 0xE038, 0xE0A7, 0xE116, 0xE186, 0xE1F5, 0xE264, 0xE2D4
.hword 0xE343, 0xE3B3, 0xE423, 0xE493, 0xE503, 0xE573, 0xE5E3, 0xE654
.hword 0xE6C4, 0xE735, 0xE7A5, 0xE816, 0xE887, 0xE8F8, 0xE969, 0xE9DA
.hword 0xEA4B, 0xEABC, 0xEB2E, 0xEB9F, 0xEC11, 0xEC83, 0xECF5, 0xED66
.hword 0xEDD9, 0xEE4B, 0xEEBD, 0xEF2F, 0xEFA2, 0xF014, 0xF087, 0xF0FA
.hword 0xF16D, 0xF1E0, 0xF253, 0xF2C6, 0xF339, 0xF3AD, 0xF420, 0xF494
.hword 0xF507, 0xF57B, 0xF5EF, 0xF663, 0xF6D7, 0xF74C, 0xF7C0, 0xF834
.hword 0xF8A9, 0xF91E, 0xF992, 0xFA07, 0xFA7C, 0xFAF1, 0xFB66, 0xFBDC
.hword 0xFC51, 0xFCC7, 0xFD3C, 0xFDB2, 0xFE28, 0xFE9E, 0xFF14, 0xFF8A
pitch_table_ptr:
.word pitch_table
swi_get_pitch_table:
add r0, r0, r0
ldr r1, pitch_table_ptr
// Should some protection be here?
ldrh r0, [ r1, r0 ]
b swi_complete
volume_table:
.byte 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01
.byte 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02
.byte 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02
.byte 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02
.byte 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02
.byte 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02
.byte 0x02, 0x02, 0x02, 0x02, 0x02, 0x03, 0x03, 0x03
.byte 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03
.byte 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03
.byte 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03
.byte 0x03, 0x03, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04
.byte 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04
.byte 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04
.byte 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05
.byte 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05
.byte 0x05, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06
.byte 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06
.byte 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07
.byte 0x07, 0x07, 0x07, 0x07, 0x08, 0x08, 0x08, 0x08
.byte 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x09
.byte 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09
.byte 0x09, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A
.byte 0x0A, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B
.byte 0x0B, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C, 0x0C
.byte 0x0C, 0x0D, 0x0D, 0x0D, 0x0D, 0x0D, 0x0D, 0x0E
.byte 0x0E, 0x0E, 0x0E, 0x0E, 0x0E, 0x0E, 0x0F, 0x0F
.byte 0x0F, 0x0F, 0x0F, 0x10, 0x10, 0x10, 0x10, 0x10
.byte 0x10, 0x11, 0x11, 0x11, 0x11, 0x11, 0x12, 0x12
.byte 0x12, 0x12, 0x12, 0x13, 0x13, 0x13, 0x13, 0x14
.byte 0x14, 0x14, 0x14, 0x14, 0x15, 0x15, 0x15, 0x15
.byte 0x16, 0x16, 0x16, 0x16, 0x17, 0x17, 0x17, 0x18
.byte 0x18, 0x18, 0x18, 0x19, 0x19, 0x19, 0x19, 0x1A
.byte 0x1A, 0x1A, 0x1B, 0x1B, 0x1B, 0x1C, 0x1C, 0x1C
.byte 0x1D, 0x1D, 0x1D, 0x1E, 0x1E, 0x1E, 0x1F, 0x1F
.byte 0x1F, 0x20, 0x20, 0x20, 0x21, 0x21, 0x22, 0x22
.byte 0x22, 0x23, 0x23, 0x24, 0x24, 0x24, 0x25, 0x25
.byte 0x26, 0x26, 0x27, 0x27, 0x27, 0x28, 0x28, 0x29
.byte 0x29, 0x2A, 0x2A, 0x2B, 0x2B, 0x2C, 0x2C, 0x2D
.byte 0x2D, 0x2E, 0x2E, 0x2F, 0x2F, 0x30, 0x31, 0x31
.byte 0x32, 0x32, 0x33, 0x33, 0x34, 0x35, 0x35, 0x36
.byte 0x36, 0x37, 0x38, 0x38, 0x39, 0x3A, 0x3A, 0x3B
.byte 0x3C, 0x3C, 0x3D, 0x3E, 0x3F, 0x3F, 0x40, 0x41
.byte 0x42, 0x42, 0x43, 0x44, 0x45, 0x45, 0x46, 0x47
.byte 0x48, 0x49, 0x4A, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E
.byte 0x4F, 0x50, 0x51, 0x52, 0x52, 0x53, 0x54, 0x55
.byte 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5D, 0x5E
.byte 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x67
.byte 0x68, 0x69, 0x6A, 0x6B, 0x6D, 0x6E, 0x6F, 0x71
.byte 0x72, 0x73, 0x75, 0x76, 0x77, 0x79, 0x7A, 0x7B
.byte 0x7D, 0x7E, 0x7F, 0x20, 0x21, 0x21, 0x21, 0x22
.byte 0x22, 0x23, 0x23, 0x23, 0x24, 0x24, 0x25, 0x25
.byte 0x26, 0x26, 0x26, 0x27, 0x27, 0x28, 0x28, 0x29
.byte 0x29, 0x2A, 0x2A, 0x2B, 0x2B, 0x2C, 0x2C, 0x2D
.byte 0x2D, 0x2E, 0x2E, 0x2F, 0x2F, 0x30, 0x30, 0x31
.byte 0x31, 0x32, 0x33, 0x33, 0x34, 0x34, 0x35, 0x36
.byte 0x36, 0x37, 0x37, 0x38, 0x39, 0x39, 0x3A, 0x3B
.byte 0x3B, 0x3C, 0x3D, 0x3E, 0x3E, 0x3F, 0x40, 0x40
.byte 0x41, 0x42, 0x43, 0x43, 0x44, 0x45, 0x46, 0x47
.byte 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4D
.byte 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55
.byte 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D
.byte 0x5E, 0x5F, 0x60, 0x62, 0x63, 0x64, 0x65, 0x66
.byte 0x67, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6F, 0x70
.byte 0x71, 0x73, 0x74, 0x75, 0x77, 0x78, 0x79, 0x7B
.byte 0x7C, 0x7E, 0x7E, 0x40, 0x41, 0x42, 0x43, 0x43
.byte 0x44, 0x45, 0x46, 0x47, 0x47, 0x48, 0x49, 0x4A
.byte 0x4B, 0x4C, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51
.byte 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59
.byte 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61
.byte 0x62, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6B
.byte 0x6C, 0x6D, 0x6E, 0x70, 0x71, 0x72, 0x74, 0x75
.byte 0x76, 0x78, 0x79, 0x7B, 0x7C, 0x7D, 0x7E, 0x40
.byte 0x41, 0x42, 0x42, 0x43, 0x44, 0x45, 0x46, 0x46
.byte 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4B, 0x4C, 0x4D
.byte 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55
.byte 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D
.byte 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x65, 0x66
.byte 0x67, 0x68, 0x69, 0x6A, 0x6C, 0x6D, 0x6E, 0x6F
.byte 0x71, 0x72, 0x73, 0x75, 0x76, 0x77, 0x79, 0x7A
.byte 0x7C, 0x7D, 0x7E, 0x7F
padding_b:
.word 0x0
swi_get_boot_procs:
mov r0, #0x2E
mov r1, #0x3C
mov r2, #0xFF
orr r0, r0, #0x0A00
orr r1, r1, #0x2C00
orr r2, r2, #0x0500
b swi_complete
#endif
swi_custom_halt_post:
mov r1, #0x4000000
#ifdef BIOS_ARM7
strb r0, [ r1, #0x301 ]
#else
strb r0, [ r1, #0x300 ]
#endif
b swi_complete
interrupt_handler:
// Save these registers, IRQ functions will be allowed to modify them w/o
// saving.
stmdb sp!, { r0 - r3, r12, lr }
#ifdef BIOS_ARM9
// Get DTCM base
mrc p15, 0, r0, cr9, cr1, 0
bic r0, r0, #0xFF
// Pointer to IRQ handler is in DTCM[0x3FFC]
add r0, r0, #0x4000
#else
// Pointer to IRQ handler is at 0x03FFFFFC (mirrored WRAM)
mov r0, #0x4000000
#endif
// Store return address and branch to handler
mov lr, pc
ldr pc, [ r0, #-4 ]
// Return from IRQ
ldmia sp!, { r0 - r3, r12, lr }
subs pc, lr, #4
#ifdef BIOS_ARM7
swi_get_volume_table:
adr r1, volume_table
// Should some protection be here?
ldrb r0, [ r1, r0 ]
b swi_complete
#endif
stack_pointer_irq:
.word 0x0380ffdc
swi_soft_reset:
// set r0 to 0x3FFFE00 (points to stack space)
mov r0, #0x4000000
mov r1, #0x80
mov r2, #0
// Clear stack space
0:
str r2, [ r0, #-4 ]!
subs r1, r1, #1
bne 0b
// Stack pointer base
ldr r1, stack_pointer_irq
// Initialize supervisor SPSR, LR, and SP (disable interrupts)
mov r3, #0xd3
msr CPSR_fsxc, r3
// sp_svc = 0x0380ffdc
mov sp, r1
mov lr, r2
msr SPSR_fsxc, r2
// Initialize IRQ SPSR, LR, and SP (disable interrupts)
mov r3, #0xd2
msr CPSR_fsxc, r3
// sp_irq = 0x0380ffb0
sub sp, r1, #(0xdc - 0xb0)
mov lr, r2
msr SPSR_fsxc, r2
// Initialize system SPSR, LR, and SP (enable interrupts)
mov r3, #0x5f
msr CPSR_fsxc, r3
// sp = 0x0380ff00
sub sp, r1, #0xdc
// Set r0-r12 to 0, r0 still points to initialized stack space
ldmia r0, { r0 - r12 }
movs pc, lr
// Pad out
#ifdef BIOS_ARM7
.org 16384
#endif
#ifdef BIOS_ARM9
.org 4096
#endif