1 files changed, 99 insertions, 2 deletions

diff --git a/rtl/nds/prt07.as b/rtl/nds/prt07.as
index 7d59f23686..69a479d217 100644
--- a/rtl/nds/prt07.as
+++ b/rtl/nds/prt07.as
@@ -1,5 +1,11 @@
+/*--------------------------------------------------------------------------------
+	This Source Code Form is subject to the terms of the Mozilla Public License,
+	v. 2.0. If a copy of the MPL was not distributed with this file, You can
+	obtain one at https://mozilla.org/MPL/2.0/.
+--------------------------------------------------------------------------------*/
+
 @---------------------------------------------------------------------------------
-	.section ".init"
+	.section ".crt0","ax"
 	.global _start
 @---------------------------------------------------------------------------------
 	.align	4
@@ -23,17 +29,105 @@ _start:
 	msr	cpsr, r0
 	ldr	sp, =__sp_usr		@ Set user stack
 
+#ifndef VRAM
+	adr	r1, __sync_start	@ Perform ARM7<->ARM9 sync code
+	ldr	r2, =__arm7_start__
+	mov	r3, #(__sync_end-__sync_start)
+	mov	r8, r2
+	bl	CopyMem
+	mov	r3, r8
+	bl	_blx_r3_stub
+
+@---------------------------------------------------------------------------------
+@ Copy arm7 binary from LMA to VMA (EWRAM to IWRAM)
+@---------------------------------------------------------------------------------
+	adr	r0, arm7lma		@ Calculate ARM7 LMA
+	ldr	r1, [r0]
+	add	r1, r1, r0
+	ldr	r2, =__arm7_start__
+	ldr	r4, =__arm7_end__
+	bl	CopyMemCheck
+
+#else
+	bl	__sync_start
+#endif
+
 	ldr	r0, =__bss_start__	@ Clear BSS section to 0x00
 	ldr	r1, =__bss_end__
 	sub	r1, r1, r0
 	bl	ClearMem
 
+	cmp	r10, #1
+	bne	NotTWL
+	ldr	r1, =__dsimode		@ set DSi mode flag
+	strb	r10, [r1]
+
+#ifndef VRAM
+	ldr	r1, =0x02ffe1d8		@ Get ARM7i LMA from header
+	ldr	r1, [r1]
+	ldr	r2, =__arm7i_start__
+	ldr	r4, =__arm7i_end__
+	bl	CopyMemCheck
+
+	ldr	r0, =__twl_bss_start__	@ Clear TWL BSS section to 0x00
+	ldr	r1, =__twl_bss_end__
+	sub	r1, r1, r0
+	bl	ClearMem
+#endif
+
+NotTWL:
+	ldr	r3, =__libc_init_array	@ global constructors
+	bl	_blx_r3_stub
+
 	mov	r0, #0			@ int argc
 	mov	r1, #0			@ char *argv[]
 	ldr	r3, =main
 	ldr	lr,=__libnds_exit
+	mov	r12, #0x4000000		@ tell arm9 we are ready
+	mov	r9, #0
+	str	r9, [r12, #0x180]
+_blx_r3_stub:
 	bx	r3
 
+#ifndef VRAM
+arm7lma:
+	.word	__arm7_lma__ - .
+#endif
+	.pool
+
+@---------------------------------------------------------------------------------
+@ ARM7<->ARM9 synchronization code
+@---------------------------------------------------------------------------------
+
+__sync_start:
+	push	{lr}
+	mov	r12, #0x4000000
+	mov	r9, #0x0
+	bl	IPCSync
+	mov	r9, #(0x9<<8)
+	str	r9, [r12, #0x180]
+	mov	r9, #0xA
+	bl	IPCSync
+	mov	r9, #(0xB<<8)
+	str	r9, [r12, #0x180]
+	mov	r9, #0xC
+	bl	IPCSync
+	mov	r9, #(0xD<<8)
+	str	r9, [r12, #0x180]
+IPCRecvFlag:
+	ldr	r10, [r12, #0x180]
+	and	r10, r10, #0xF
+	cmp	r10, #0xC
+	beq	IPCRecvFlag
+	pop	{pc}
+IPCSync:
+	ldr	r10, [r12, #0x180]
+	and	r10, r10, #0xF
+	cmp	r10, r9
+	bne	IPCSync
+	bx	lr
+__sync_end:
+
 @---------------------------------------------------------------------------------
 @ Clear memory to 0x00 if length != 0
 @  r0 = Start Address
@@ -61,6 +155,9 @@ ClrLoop:
 @---------------------------------------------------------------------------------
 CopyMemCheck:
 @---------------------------------------------------------------------------------
+	cmp	r1, r2
+	bxeq	lr
+
 	sub	r3, r4, r2		@ Is there any data to copy?
 @---------------------------------------------------------------------------------
 @ Copy memory
@@ -85,4 +182,4 @@ CIDLoop:
 	.align
 	.pool
 	.end
-@---------------------------------------------------------------------------------
+@---------------------------------------------------------------------------------
\ No newline at end of file