nuclear@0: @ vi:set filetype=armasm:
nuclear@0: 	.section ".crt0","ax"
nuclear@0: 	.global _start
nuclear@0: 	.align	4
nuclear@0: 	.arm
nuclear@0: _start:
nuclear@0: 	mov	r0, #0x04000000		@ IME = 0;
nuclear@0: 	mov	r1, #0
nuclear@0: 	str	r1, [r0, #0x208]
nuclear@0: 
nuclear@0: 	mov	r0, #0x12		@ Switch to IRQ Mode
nuclear@0: 	msr	cpsr, r0
nuclear@0: 	ldr	sp, =__sp_irq		@ Set IRQ stack
nuclear@0: 
nuclear@0: 	mov	r0, #0x13		@ Switch to SVC Mode
nuclear@0: 	msr	cpsr, r0
nuclear@0: 	ldr	sp, =__sp_svc		@ Set SVC stack
nuclear@0: 
nuclear@0: 	mov	r0, #0x1F		@ Switch to System Mode
nuclear@0: 	msr	cpsr, r0
nuclear@0: 	ldr	sp, =__sp_usr		@ Set user stack
nuclear@0: 
nuclear@0: #ifndef VRAM
nuclear@0: 	adr	r1, __sync_start	@ Perform ARM7<->ARM9 sync code
nuclear@0: 	ldr	r2, =__arm7_start__
nuclear@0: 	mov	r3, #(__sync_end-__sync_start)
nuclear@0: 	mov	r8, r2
nuclear@0: 	bl	CopyMem
nuclear@0: 	mov	r3, r8
nuclear@0: 	bl	_blx_r3_stub
nuclear@0: 
nuclear@0: @ Copy arm7 binary from LMA to VMA (EWRAM to IWRAM)
nuclear@0: 	adr	r0, arm7lma		@ Calculate ARM7 LMA
nuclear@0: 	ldr	r1, [r0]
nuclear@0: 	add	r1, r1, r0
nuclear@0: 	ldr	r2, =__arm7_start__
nuclear@0: 	ldr	r4, =__arm7_end__
nuclear@0: 	bl	CopyMemCheck
nuclear@0: 
nuclear@0: #else
nuclear@0: 	bl	__sync_start
nuclear@0: #endif
nuclear@0: 
nuclear@0: 	ldr	r0, =__bss_start__	@ Clear BSS section to 0x00
nuclear@0: 	ldr	r1, =__bss_end__
nuclear@0: 	sub	r1, r1, r0
nuclear@0: 	bl	ClearMem
nuclear@0: 
nuclear@0: #ifndef VRAM
nuclear@0: 	cmp	r10, #1
nuclear@0: 	bne	NotTWL
nuclear@0: 	ldr	r1, =__dsimode		@ set DSi mode flag
nuclear@0: 	strb	r10, [r1]
nuclear@0: 
nuclear@0: 	ldr	r1, =0x02ffe1d8		@ Get ARM7i LMA from header
nuclear@0: 	ldr	r1, [r1]
nuclear@0: 	ldr	r2, =__arm7i_start__
nuclear@0: 	ldr	r4, =__arm7i_end__
nuclear@0: 	bl	CopyMemCheck
nuclear@0: 
nuclear@0: 	ldr	r0, =__twl_bss_start__	@ Clear TWL BSS section to 0x00
nuclear@0: 	ldr	r1, =__twl_bss_end__
nuclear@0: 	sub	r1, r1, r0
nuclear@0: 	bl	ClearMem
nuclear@0: #endif
nuclear@0: 
nuclear@0: NotTWL:
nuclear@0: 	mov	r0, #0			@ int argc
nuclear@0: 	mov	r1, #0			@ char *argv[]
nuclear@0: 	ldr	r3, =main
nuclear@0: 	mov	r12, #0x4000000		@ tell arm9 we are ready
nuclear@0: 	mov	r9, #0
nuclear@0: 	str	r9, [r12, #0x180]
nuclear@0: _blx_r3_stub:
nuclear@0: 	bx	r3
nuclear@0: infloop:
nuclear@0: 	b infloop
nuclear@0: 
nuclear@0: #ifndef VRAM
nuclear@0: arm7lma:
nuclear@0: 	.word	__arm7_lma__ - .
nuclear@0: #endif
nuclear@0: 	.pool
nuclear@0: 
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: @ ARM7<->ARM9 synchronization code
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: 
nuclear@0: __sync_start:
nuclear@0: 	push	{lr}
nuclear@0: 	mov	r12, #0x4000000
nuclear@0: 	mov	r9, #0x0
nuclear@0: 	bl	IPCSync
nuclear@0: 	mov	r9, #(0x9<<8)
nuclear@0: 	str	r9, [r12, #0x180]
nuclear@0: 	mov	r9, #0xA
nuclear@0: 	bl	IPCSync
nuclear@0: 	mov	r9, #(0xB<<8)
nuclear@0: 	str	r9, [r12, #0x180]
nuclear@0: 	mov	r9, #0xC
nuclear@0: 	bl	IPCSync
nuclear@0: 	mov	r9, #(0xD<<8)
nuclear@0: 	str	r9, [r12, #0x180]
nuclear@0: IPCRecvFlag:
nuclear@0: 	ldr	r10, [r12, #0x180]
nuclear@0: 	and	r10, r10, #0xF
nuclear@0: 	cmp	r10, #0xC
nuclear@0: 	beq	IPCRecvFlag
nuclear@0: 	pop	{pc}
nuclear@0: IPCSync:
nuclear@0: 	ldr	r10, [r12, #0x180]
nuclear@0: 	and	r10, r10, #0xF
nuclear@0: 	cmp	r10, r9
nuclear@0: 	bne	IPCSync
nuclear@0: 	bx	lr
nuclear@0: __sync_end:
nuclear@0: 
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: @ Clear memory to 0x00 if length != 0
nuclear@0: @  r0 = Start Address
nuclear@0: @  r1 = Length
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: ClearMem:
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: 	mov	r2, #3			@ Round down to nearest word boundary
nuclear@0: 	add	r1, r1, r2		@ Shouldn't be needed
nuclear@0: 	bics	r1, r1, r2		@ Clear 2 LSB (and set Z)
nuclear@0: 	bxeq	lr			@ Quit if copy size is 0
nuclear@0: 
nuclear@0: 	mov	r2, #0
nuclear@0: ClrLoop:
nuclear@0: 	stmia	r0!, {r2}
nuclear@0: 	subs	r1, r1, #4
nuclear@0: 	bne	ClrLoop
nuclear@0: 	bx	lr
nuclear@0: 
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: @ Copy memory if length	!= 0
nuclear@0: @  r1 = Source Address
nuclear@0: @  r2 = Dest Address
nuclear@0: @  r4 = Dest Address + Length
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: CopyMemCheck:
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: 	cmp	r1, r2
nuclear@0: 	bxeq	lr
nuclear@0: 
nuclear@0: 	sub	r3, r4, r2		@ Is there any data to copy?
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: @ Copy memory
nuclear@0: @  r1 = Source Address
nuclear@0: @  r2 = Dest Address
nuclear@0: @  r3 = Length
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: CopyMem:
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: 	mov	r0, #3			@ These commands are used in cases where
nuclear@0: 	add	r3, r3, r0		@ the length is not a multiple of 4,
nuclear@0: 	bics	r3, r3, r0		@ even though it should be.
nuclear@0: 	bxeq	lr			@ Length is zero, so exit
nuclear@0: CIDLoop:
nuclear@0: 	ldmia	r1!, {r0}
nuclear@0: 	stmia	r2!, {r0}
nuclear@0: 	subs	r3, r3, #4
nuclear@0: 	bne	CIDLoop
nuclear@0: 	bx	lr
nuclear@0: 
nuclear@0: @---------------------------------------------------------------------------------
nuclear@0: 	.align
nuclear@0: 	.pool
nuclear@0: 
nuclear@0: 	.global __dsimode
nuclear@0: __dsimode: .word
nuclear@0: 	.end
nuclear@0: @---------------------------------------------------------------------------------