split out files and add build batch file

7 files changed, 236 insertions, 206 deletions

diff --git a/asm/crt0.s b/asm/crt0.s
new file mode 100644
index 000000000..544c3b173
--- /dev/null
+++ b/asm/crt0.s
@@ -0,0 +1,133 @@
+	.include "rom_header.s"
+
+_080000C0:
+	.long 0
+
+_080000C4:
+	.short 0
+
+_080000C6:
+	.short 0
+
+_080000C8:
+	.long 0
+
+	.incbin "base_emerald.gba", 0xCC, 0x204 - 0xCC
+
+	arm_func_start 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, InterruptMain
+	str r0, [r1]
+	ldr r1, =Main + 1
+	mov lr, pc
+	bx r1
+	b Init
+
+	.align 2, 0
+sp_sys: .4byte IWRAM_END - 0x1c0
+sp_irq: .4byte IWRAM_END - 0x60
+
+	.pool
+
+	arm_func_end Init
+
+	arm_func_start InterruptMain
+InterruptMain:
+	mov r3, 0x4000000
+	add r3, r3, 0x200
+	ldr r2, [r3]
+	ldrh r1, [r3, 0x8]
+	mrs r0, spsr
+	stmdb sp!, {r0-r3,lr}
+	mov r0, 0
+	strh r0, [r3, 0x8]
+	and r1, r2, r2, lsr 16
+	mov r12, 0
+	ands r0, r1, 0x4
+	bne _08000320
+	add r12, r12, 0x4
+	mov r0, 0x1
+	strh r0, [r3, 0x8]
+	ands r0, r1, 0x80
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x40
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x2
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x1
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x8
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x10
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x20
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x100
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x200
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x400
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x800
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x1000
+	bne _08000320
+	add r12, r12, 0x4
+	ands r0, r1, 0x2000
+	strbne r0, [r3, -0x17C]
+_0800031C:
+	bne _0800031C
+_08000320:
+	strh r0, [r3, 0x2]
+	bic r2, r2, r0
+	ldr r0, =0x03007868
+	ldr r0, [r0]
+	ldrb r0, [r0, 0xA]
+	mov r1, 0x8
+	mov r0, r1, lsl r0
+	orr r0, r0, 0x2000
+	orr r1, r0, 0xC6
+	and r1, r1, r2
+	strh r1, [r3]
+	mrs r3, cpsr
+	bic r3, r3, 0xDF
+	orr r3, r3, 0x1F
+	msr cpsr_cf, r3
+	ldr r1, =0x03002710
+	add r1, r1, r12
+	ldr r0, [r1]
+	stmdb sp!, {lr}
+	add lr, pc, 0
+	bx r0
+	ldmia sp!, {lr}
+	mrs r3, cpsr
+	bic r3, r3, 0xDF
+	orr r3, r3, 0x92
+	msr cpsr_cf, r3
+	ldmia sp!, {r0-r3,lr}
+	strh r2, [r3]
+	strh r1, [r3, 0x8]
+	msr spsr_cf, r0
+	bx lr
+
+	.pool
+
+	arm_func_end InterruptMain
diff --git a/asm/defines.s b/asm/defines.s
new file mode 100644
index 000000000..bc18a616c
--- /dev/null
+++ b/asm/defines.s
@@ -0,0 +1,14 @@
+	.set PSR_USR_MODE, 0x00000010
+	.set PSR_FIQ_MODE, 0x00000011
+	.set PSR_IRQ_MODE, 0x00000012
+	.set PSR_SVC_MODE, 0x00000013
+	.set PSR_ABT_MODE, 0x00000017
+	.set PSR_UND_MODE, 0x0000001b
+	.set PSR_SYS_MODE, 0x0000001f
+
+	.set EWRAM_START, 0x02000000
+	.set EWRAM_END,   EWRAM_START + 0x40000
+	.set IWRAM_START, 0x03000000
+	.set IWRAM_END,   IWRAM_START + 0x8000
+
+	.set INTR_VECTOR, IWRAM_END - 0x4
diff --git a/asm/emerald.s b/asm/emerald.s
index 91f75383e..96f032a55 100644
--- a/asm/emerald.s
+++ b/asm/emerald.s
@@ -1,214 +1,20 @@
-	.macro arm_func_start name
-	.align 2, 0
-	.global \name
-	.arm
-	.type \name, %function
-	.endm
-
-	.macro arm_func_end name
-	.size \name, .-\name
-	.endm
-
-	.macro thumb_func_start name
-	.align 2, 0
-	.global \name
-	.thumb
-	.thumb_func
-	.type \name, %function
-	.endm
-
-	.macro non_word_aligned_thumb_func_start name
-	.global \name
-	.thumb
-	.thumb_func
-	.type \name, %function
-	.endm
-
-	.macro thumb_func_end name
-	.size \name, .-\name
-	.endm
+	.include "defines.s"
+	.include "macros.s"
 
 	.syntax unified
 
-	.global RomBase
+	.global Start
 
 	.text
 
 	.arm
 
-RomBase:
-    b start_loop
-
-CartridgeHeaderNintendoLogo:
-	.incbin "base_emerald.gba", 0x4, 0xA0 - 0x4
-
-CartridgeHeaderGameTitle:
-	.ascii "POKEMON EMER"
-
-CartridgeHeaderGameCode:
-	.ascii "BPEE"
-
-CartridgeHeaderMakerCode:
-	.ascii "01"
-
-CartridgeHeaderMagic:
-	.byte 0x96
-
-CartridgeHeaderMainUnitCode:
-	.byte 0
-
-CartridgeHeaderDeviceType:
-	.byte 0
-
-CartridgeHeaderReserved1:
-	.rept 7
-	.byte 0
-	.endr
-
-CartridgeHeaderSoftwareVersion:
-	.byte 0
-
-CartridgeHeaderChecksum:
-	.byte 0x72
-
-CartridgeHeaderReserved2:
-	.rept 2
-	.byte 0
-	.endr
-
-_080000C0:
-	.long 0
-
-_080000C4:
-	.short 0
-
-_080000C6:
-	.short 0
-
-_080000C8:
-	.long 0
-
-	.incbin "base_emerald.gba", 0xCC, 0x204 - 0xCC
-
-	arm_func_start start_loop
-start_loop: @ 8000204
-	mov r0, 0x12
-	msr cpsr_cf, r0
-	ldr sp, _0800023C
-	mov r0, 0x1F
-	msr cpsr_cf, r0
-	ldr sp, _08000238
-	ldr r1, _08000240
-	add r0, pc, 0x20
-	str r0, [r1]
-	ldr r1, _08000244
-	mov lr, pc
-	bx r1
-	b start_loop
-	.align 2, 0
-_08000238: .4byte 0x03007e40
-_0800023C: .4byte 0x03007fa0
-_08000240: .4byte 0x03007ffc
-_08000244: .4byte main_loop + 1
-	arm_func_end start_loop
-
-	arm_func_start irq_handler
-irq_handler: @ 8000248
-	mov r3, 0x4000000
-	add r3, r3, 0x200
-	ldr r2, [r3]
-	ldrh r1, [r3, 0x8]
-	mrs r0, spsr
-	stmdb sp!, {r0-r3,lr}
-	mov r0, 0
-	strh r0, [r3, 0x8]
-	and r1, r2, r2, lsr 16
-	mov r12, 0
-	ands r0, r1, 0x4
-	bne _08000320
-	add r12, r12, 0x4
-	mov r0, 0x1
-	strh r0, [r3, 0x8]
-	ands r0, r1, 0x80
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x40
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x2
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x1
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x8
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x10
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x20
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x100
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x200
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x400
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x800
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x1000
-	bne _08000320
-	add r12, r12, 0x4
-	ands r0, r1, 0x2000
-	strbne r0, [r3, -0x17C]
-_0800031C:
-	bne _0800031C
-_08000320:
-	strh r0, [r3, 0x2]
-	bic r2, r2, r0
-	ldr r0, _0800039C
-	ldr r0, [r0]
-	ldrb r0, [r0, 0xA]
-	mov r1, 0x8
-	mov r0, r1, lsl r0
-	orr r0, r0, 0x2000
-	orr r1, r0, 0xC6
-	and r1, r1, r2
-	strh r1, [r3]
-	mrs r3, cpsr
-	bic r3, r3, 0xDF
-	orr r3, r3, 0x1F
-	msr cpsr_cf, r3
-	ldr r1, _080003A0
-	add r1, r1, r12
-	ldr r0, [r1]
-	stmdb sp!, {lr}
-	add lr, pc, 0
-	bx r0
-	ldmia sp!, {lr}
-	mrs r3, cpsr
-	bic r3, r3, 0xDF
-	orr r3, r3, 0x92
-	msr cpsr_cf, r3
-	ldmia sp!, {r0-r3,lr}
-	strh r2, [r3]
-	strh r1, [r3, 0x8]
-	msr spsr_cf, r0
-	bx lr
-	.align 2, 0
-_0800039C: .4byte 0x03007868
-_080003A0: .4byte 0x03002710
-	arm_func_end irq_handler
+Start:
+	.include "crt0.s"
 
 	.thumb
-	thumb_func_start main_loop
-main_loop: @ 80003A4
+	thumb_func_start Main
+Main:
 	push {r4-r7,lr}
 	mov r7, r8
 	push {r7}
@@ -321,7 +127,7 @@ _080004B2:
 	b _0800042A
 	.align 2, 0
 _080004C0: .4byte 0x030022b4
-	thumb_func_end main_loop
+	thumb_func_end Main
 
 	thumb_func_start call_callbacks_wrapper
 call_callbacks_wrapper: @ 80004C4
@@ -605,7 +411,7 @@ _08000690:
 	pop {r0}
 	bx r0
 	.align 2, 0
-_080006D0: .4byte irq_handler
+_080006D0: .4byte InterruptMain
 _080006D4: .4byte 0x03002750
 _080006D8: .4byte 0x082e9548
 _080006DC: .4byte 0x03002710
@@ -56771,8 +56577,8 @@ _0801B688: .4byte 0x03005d90
 _0801B68C: .4byte 0x03005d8c
 _0801B690: .4byte 0x00003564
 _0801B694: .4byte 0x00002bb0
-_0801B698: .4byte CartridgeHeaderGameCode
-_0801B69C: .4byte CartridgeHeaderSoftwareVersion
+_0801B698: .4byte RomHeaderGameCode
+_0801B69C: .4byte RomHeaderSoftwareVersion
 	thumb_func_end sub_801B580
 
 	thumb_func_start sub_801B6A0
@@ -972091,7 +971897,7 @@ _082DEE76:
 	.align 2, 0
 _082DEE78: .4byte 0x0000a1c1
 _082DEE7C: .4byte 0x6177614b
-_082DEE80: .4byte CartridgeHeaderNintendoLogo
+_082DEE80: .4byte RomHeaderNintendoLogo
 	thumb_func_end sub_82DED84
 
 	thumb_func_start sub_82DEE84
diff --git a/asm/macros.s b/asm/macros.s
new file mode 100644
index 000000000..b109595df
--- /dev/null
+++ b/asm/macros.s
@@ -0,0 +1,29 @@
+	.macro arm_func_start name
+	.align 2, 0
+	.global \name
+	.arm
+	.type \name, %function
+	.endm
+
+	.macro arm_func_end name
+	.size \name, .-\name
+	.endm
+
+	.macro thumb_func_start name
+	.align 2, 0
+	.global \name
+	.thumb
+	.thumb_func
+	.type \name, %function
+	.endm
+
+	.macro non_word_aligned_thumb_func_start name
+	.global \name
+	.thumb
+	.thumb_func
+	.type \name, %function
+	.endm
+
+	.macro thumb_func_end name
+	.size \name, .-\name
+	.endm
diff --git a/asm/rom_header.s b/asm/rom_header.s
new file mode 100644
index 000000000..a9cbf9429
--- /dev/null
+++ b/asm/rom_header.s
@@ -0,0 +1,38 @@
+    b Init
+
+RomHeaderNintendoLogo:
+	.incbin "base_emerald.gba", 0x4, 0xA0 - 0x4
+
+RomHeaderGameTitle:
+	.ascii "POKEMON EMER"
+
+RomHeaderGameCode:
+	.ascii "BPEE"
+
+RomHeaderMakerCode:
+	.ascii "01"
+
+RomHeaderMagic:
+	.byte 0x96
+
+RomHeaderMainUnitCode:
+	.byte 0
+
+RomHeaderDeviceType:
+	.byte 0
+
+RomHeaderReserved1:
+	.rept 7
+	.byte 0
+	.endr
+
+RomHeaderSoftwareVersion:
+	.byte 0
+
+RomHeaderChecksum:
+	.byte 0x72
+
+RomHeaderReserved2:
+	.rept 2
+	.byte 0
+	.endr
diff --git a/build.bat b/build.bat
new file mode 100644
index 000000000..c459340a3
--- /dev/null
+++ b/build.bat
@@ -0,0 +1,4 @@
+as -mcpu=arm7tdmi asm/emerald.s -Iasm
+ld -T ld_script.txt -o emerald.o a.out
+objcopy -O binary emerald.o emerald.gba
+fc /b base_emerald.gba emerald.gba
diff --git a/ld_script.txt b/ld_script.txt
new file mode 100644
index 000000000..48982d49d
--- /dev/null
+++ b/ld_script.txt
@@ -0,0 +1,6 @@
+ENTRY(Start)
+
+SECTIONS {
+    . = 0x8000000;
+    .text : { *(.text); }
+}