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Merge pull request #90 from gwilymk/multiboot-support

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Multiboot support
This commit is contained in:
Corwin 2021-07-19 17:53:01 +01:00 committed by GitHub
parent b0afeade99 7e3b983e80
commit 97cbc8c9a6
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GPG key ID: 4AEE18F83AFDEB23
5 changed files with 254 additions and 16 deletions
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2
.github/workflows/linker-script.yml vendored
View file

@ -10,3 +10,5 @@ jobs:
uses: actions/checkout@v2
- name: Check if gba.ld files are identical
run: cmp --silent -- "agb/gba.ld" "template/gba.ld"
- name: Check if gba_mb.ld files are identical
run: cmp --silent -- "agb/gba_mb.ld" "template/gba_mb.ld"

1
agb/build.rs
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@ -2,6 +2,7 @@ use agb_image_converter::{convert_image, Colour, ImageConverterConfig, TileSize}
fn main() {
println!("cargo:rerun-if-changed=crt0.s");
println!("cargo:rerun-if-changed=gba_mb.ld");
println!("cargo:rerun-if-changed=interrupt_simple.s");
println!("cargo:rerun-if-changed=gfx/test_logo.png");

53
agb/crt0.s
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@ -6,30 +6,47 @@ __start:
@ Filled in by gbafix
.fill 188, 1, 0
@ multiboot launch point
b .Initialise_mb
.byte 0 @ boot mode, BIOS overwrites this value
.byte 0 @ slave ID number
.fill 26, 1, 0 @ unused?
.word 0 @ joybus entrypoint
.Initialise_mb:
swi 0x00250000
@ Set interrupt handler
ldr r0, =InterruptHandlerSimple
ldr r1, =0x03007FFC
str r0, [r1]
b .CommonInit
.Initialise:
@ Set interrupt handler
ldr r0, =InterruptHandlerSimple
ldr r1, =0x03007FFC
str r0, [r1]
@ copies iwram section in rom to iwram in ram
ldr r0, =__iwram_rom_start @ load memory address storing start of data for iwram in rom
ldr r1, =__iwram_data_start @ load memory address storing location of iwram in ram
ldr r2, =__iwram_rom_length_halfwords @ load number of 16 bit values to copy
swi 0x000B0000 @ call interrupt CpuSet.
@ r0: source
@ r1: destination
@ r2: length + size information
@
@ see: https://mgba-emu.github.io/gbatek/#swi-0bh-gbands7nds9dsi7dsi9---cpuset
@ copies ewram section in rom to ewram in ram
ldr r0, =__ewram_rom_start
ldr r1, =__ewram_data_start
ldr r2, =__ewram_rom_length_halfwords
swi 0x000B0000
ldr r0, =__ewram_rom_start @ load memory address storing start of data for ewram in rom
ldr r1, =__ewram_data_start @ load memory address storing location of ewram in ram
ldr r2, =__ewram_rom_length_halfwords @ load number of 16 bit values to copy
swi 0x000B0000 @ call interrupt CpuSet.
@ r0: source
@ r1: destination
@ r2: length + size information
@
@ see: https://mgba-emu.github.io/gbatek/#swi-0bh-gbands7nds9dsi7dsi9---cpuset
.CommonInit:
@ copies iwram section in rom to iwram in ram
ldr r0, =__iwram_rom_start
ldr r1, =__iwram_data_start
ldr r2, =__iwram_rom_length_halfwords
swi 0x000B0000
@ put zero in both r0 and r1
@ This corresponds to zero for argc and argv (which would technically be required for a c runtime)
@ -39,6 +56,10 @@ __start:
@ load main and branch
ldr r2, =main
bx r2
@ loop if we end up here
1:
b 1b
.pool
.include "interrupt_simple.s"

107
agb/gba_mb.ld Normal file
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@ -0,0 +1,107 @@
OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm", "elf32-littlearm")
OUTPUT_ARCH(arm)
ENTRY(__start)
MEMORY {
ewram (w!x) : ORIGIN = 0x02000000, LENGTH = 256K
iwram (w!x) : ORIGIN = 0x03000000, LENGTH = 32K
}
__text_start = ORIGIN(ewram);
SECTIONS {
. = __text_start;
.crt0 : {
KEEP (crt0.o(.text));
. = ALIGN(4);
} > ewram
.text : {
*(.text .text*);
. = ALIGN(4);
} > ewram
__text_end = .;
.rodata : {
*(.rodata .rodata.*);
. = ALIGN(4);
} > ewram
__iwram_rom_start = .;
.iwram : {
__iwram_data_start = ABSOLUTE(.);
*(.iwram .iwram.*);
. = ALIGN(4);
*(.text_iwram .text_iwram.*);
. = ALIGN(4);
__iwram_data_end = ABSOLUTE(.);
} > iwram AT>ewram
. = __iwram_rom_start + (__iwram_data_end - __iwram_data_start);
__ewram_rom_start = .;
.ewram : {
__ewram_data_start = ABSOLUTE(.);
*(.ewram .ewram.*);
. = ALIGN(4);
*(.data .data.*);
. = ALIGN(4);
__ewram_data_end = ABSOLUTE(.);
} > ewram AT>ewram
.bss : {
*(.bss .bss.*);
. = ALIGN(4);
} > iwram
__iwram_rom_length_bytes = __iwram_data_end - __iwram_data_start;
__iwram_rom_length_halfwords = (__iwram_rom_length_bytes + 1) / 2;
__ewram_rom_length_bytes = __ewram_data_end - __ewram_data_start;
__ewram_rom_length_halfwords = (__ewram_rom_length_bytes + 1) / 2;
/* debugging sections */
/* Stabs */
.stab 0 : { *(.stab) }
.stabstr 0 : { *(.stabstr) }
.stab.excl 0 : { *(.stab.excl) }
.stab.exclstr 0 : { *(.stab.exclstr) }
.stab.index 0 : { *(.stab.index) }
.stab.indexstr 0 : { *(.stab.indexstr) }
.comment 0 : { *(.comment) }
/* DWARF 1 */
.debug 0 : { *(.debug) }
.line 0 : { *(.line) }
/* GNU DWARF 1 extensions */
.debug_srcinfo 0 : { *(.debug_srcinfo) }
.debug_sfnames 0 : { *(.debug_sfnames) }
/* DWARF 1.1 and DWARF 2 */
.debug_aranges 0 : { *(.debug_aranges) }
.debug_pubnames 0 : { *(.debug_pubnames) }
/* DWARF 2 */
.debug_info 0 : { *(.debug_info) }
.debug_abbrev 0 : { *(.debug_abbrev) }
.debug_line 0 : { *(.debug_line) }
.debug_frame 0 : { *(.debug_frame) }
.debug_str 0 : { *(.debug_str) }
.debug_loc 0 : { *(.debug_loc) }
.debug_macinfo 0 : { *(.debug_macinfo) }
/* SGI/MIPS DWARF 2 extensions */
.debug_weaknames 0 : { *(.debug_weaknames) }
.debug_funcnames 0 : { *(.debug_funcnames) }
.debug_typenames 0 : { *(.debug_typenames) }
.debug_varnames 0 : { *(.debug_varnames) }
.debug_ranges 0 : { *(.debug_ranges) }
/* discard anything not already mentioned */
/DISCARD/ : { *(*) }
}

107
template/gba_mb.ld Normal file
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@ -0,0 +1,107 @@
OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm", "elf32-littlearm")
OUTPUT_ARCH(arm)
ENTRY(__start)
MEMORY {
ewram (w!x) : ORIGIN = 0x02000000, LENGTH = 256K
iwram (w!x) : ORIGIN = 0x03000000, LENGTH = 32K
}
__text_start = ORIGIN(ewram);
SECTIONS {
. = __text_start;
.crt0 : {
KEEP (crt0.o(.text));
. = ALIGN(4);
} > ewram
.text : {
*(.text .text*);
. = ALIGN(4);
} > ewram
__text_end = .;
.rodata : {
*(.rodata .rodata.*);
. = ALIGN(4);
} > ewram
__iwram_rom_start = .;
.iwram : {
__iwram_data_start = ABSOLUTE(.);
*(.iwram .iwram.*);
. = ALIGN(4);
*(.text_iwram .text_iwram.*);
. = ALIGN(4);
__iwram_data_end = ABSOLUTE(.);
} > iwram AT>ewram
. = __iwram_rom_start + (__iwram_data_end - __iwram_data_start);
__ewram_rom_start = .;
.ewram : {
__ewram_data_start = ABSOLUTE(.);
*(.ewram .ewram.*);
. = ALIGN(4);
*(.data .data.*);
. = ALIGN(4);
__ewram_data_end = ABSOLUTE(.);
} > ewram AT>ewram
.bss : {
*(.bss .bss.*);
. = ALIGN(4);
} > iwram
__iwram_rom_length_bytes = __iwram_data_end - __iwram_data_start;
__iwram_rom_length_halfwords = (__iwram_rom_length_bytes + 1) / 2;
__ewram_rom_length_bytes = __ewram_data_end - __ewram_data_start;
__ewram_rom_length_halfwords = (__ewram_rom_length_bytes + 1) / 2;
/* debugging sections */
/* Stabs */
.stab 0 : { *(.stab) }
.stabstr 0 : { *(.stabstr) }
.stab.excl 0 : { *(.stab.excl) }
.stab.exclstr 0 : { *(.stab.exclstr) }
.stab.index 0 : { *(.stab.index) }
.stab.indexstr 0 : { *(.stab.indexstr) }
.comment 0 : { *(.comment) }
/* DWARF 1 */
.debug 0 : { *(.debug) }
.line 0 : { *(.line) }
/* GNU DWARF 1 extensions */
.debug_srcinfo 0 : { *(.debug_srcinfo) }
.debug_sfnames 0 : { *(.debug_sfnames) }
/* DWARF 1.1 and DWARF 2 */
.debug_aranges 0 : { *(.debug_aranges) }
.debug_pubnames 0 : { *(.debug_pubnames) }
/* DWARF 2 */
.debug_info 0 : { *(.debug_info) }
.debug_abbrev 0 : { *(.debug_abbrev) }
.debug_line 0 : { *(.debug_line) }
.debug_frame 0 : { *(.debug_frame) }
.debug_str 0 : { *(.debug_str) }
.debug_loc 0 : { *(.debug_loc) }
.debug_macinfo 0 : { *(.debug_macinfo) }
/* SGI/MIPS DWARF 2 extensions */
.debug_weaknames 0 : { *(.debug_weaknames) }
.debug_funcnames 0 : { *(.debug_funcnames) }
.debug_typenames 0 : { *(.debug_typenames) }
.debug_varnames 0 : { *(.debug_varnames) }
.debug_ranges 0 : { *(.debug_ranges) }
/* discard anything not already mentioned */
/DISCARD/ : { *(*) }
}