9.6+ emunand!

emunand/emuCode.s

@@ -1,155 +1,50 @@
 .nds
 
-sdmmc equ 0x80D86F0
-sdmmc_unk1 equ 0x080788C0
-aes_unk equ 0x0805F9E4
-aes_setkey equ 0x08057458
-sdmmc_unk2 equ 0x080786A0
-sdmmc_unk0 equ 0x08062890
+sdmmc equ 0x080D86F0
 
 .create "emunand.bin", 0x0801A4C0
 .org 0x0801A4C0
 .arm
-EMU_WRITE:
-	stmfd sp!, {r0-r3}
-	mov r3, r0
-	ldr r1, =orig_sector
-	ldr r2, [r3,#4]
-	str r2, [r1,#4]
-	ldr r0, =sdmmc
-	cmp r2, r0
-	ldr r2, [r3,#8]
-	str r2, [r1]
-	beq @@orig_code
-	ldr r1, =sdmmc
-	str r1, [r3,#4]
-	cmp r2, #0
-	ldr r0, =nand_offset
-	ldrne r0, [r0]
-	addne r0, r2
-	ldreq r0, [r0, #(ncsd_header_offset - nand_offset)]
-	str r0, [r3,#8]
-@@orig_code:
-	ldmfd sp!, {r0-r3}
-	movs r4, r0
-	movs r5, r1
-	movs r7, r2
-	movs r6, r3
-	movs r0, r1, lsl#23
-	beq loc_801a534
-	stmfd sp!, {r4}
-	ldr r4, =(sdmmc_unk0 + 1)
-	blx r4
-	ldmfd sp!, {r4}
-loc_801a534:
-	ldr r0, [r4,#4]
-	ldr r1, [r0]
-	ldr r1, [r1,#0x18]
-	blx r1
-	ldr r1, [r4,#4]
-	movs r3, r0
-	ldr r0, [r1,#0x20]
-	movs r2, r5, lsr#9
-	mov r12, r0
-	ldr r0, [r4,#8]
-	str r7, [sp,#4]
-	adds r0, r0, r2
-	cmp r1, #0
-	str r6, [sp,#8]
-	str r0, [sp]
-	beq loc_801a578
-	adds r1, r1, #8
-loc_801a578:
-	movs r2, r4
-	adds r2, r2, #0xc
-	mov r0, r12
-	ldr r5, =(sdmmc_unk1 + 1) ; called by the original function
-	blx r5
-	stmfd sp!, {r0-r3}
-	ldr r2, =orig_sector
-	ldr r1, [r2]
-	str r1, [r4,#8]
-	ldr r1, [r2,#4]
-	str r1, [r4,#4]
-	ldmfd sp!, {r0-r3}
-	ldmfd sp!, {r1-r7,lr}
-	bx lr
+nand_sd:
+    ; Original code that still needs to be executed.
+    mov r4, r0
+    mov r5, r1
+    mov r7, r2
+    mov r6, r3
+    ; End.
 
-EMU_READ:
-	stmfd sp!, {r0-r3}
-	mov r3, r0
-	ldr r1, =orig_sector
-	ldr r2, [r3,#4]
-	str r2, [r1,#4]
-	ldr r0, =sdmmc
-	cmp r2, r0
-	ldr r2, [r3,#8]
-	str r2, [r1]
-	beq @@orig_code
-	ldr r1, =sdmmc
-	str r1, [r3,#4]
-	cmp r2, #0
-	ldr r0, =nand_offset
-	ldrne r0, [r0]
-	addne r0, r2
-	ldreq r0, [r0, #(ncsd_header_offset - nand_offset)]
-	str r0, [r3,#8]
-@@orig_code:
-	ldmfd sp!, {r0-r3}
-	movs r4, r0
-	movs r5, r1
-	movs r7, r2
-	movs r6, r3
-	movs r0, r1, lsl#23
-	beq loc_801a624
-	stmfd sp!, {r4}
-	ldr r4, =(sdmmc_unk0 + 1)
-	blx r4
-	ldmfd sp!, {r4}
-loc_801a624:
-	ldr r0, [r4,#4]
-	ldr r1, [r0]
-	ldr r1, [r1,#0x18]
-	blx r1
-	ldr r1, [r4,#4]
-	movs r3, r0
-	ldr r0, [r1,#0x20]
-	movs r2, r5, lsr#9
-	mov r12, r0
-	ldr r0, [r4,#8]
-	str r7, [sp,#4]
-	adds r0, r0, r2
-	cmp r1, #0
-	str r6, [sp,#8]
-	str r0, [sp]
-	beq loc_801a668
-	adds r1, r1, #8
-loc_801a668:
-	movs r2, r4
-	adds r2, r2, #0xC
-	mov r0, r12
-	ldr r5, =(sdmmc_unk2 + 1)
-	blx r5
-	stmfd sp!, {r0-r3}
-	ldr r2, =orig_sector
-	ldr r1, [r2]
-	str r1, [r4,#8]
-	ldr r1, [r2,#4]
-	str r1, [r4,#4]
-	ldmfd sp!, {r0-r3}
-	ldmfd sp!, {r1-r7,lr}
-	bx lr
+    ; If we're already trying to access the SD, return.
+    ldr r2, [r0, #4]
+    ldr r1, =sdmmc
+    cmp r2, r1
+    beq nand_sd_ret
 
+    str r1, [r0, #4]  ; Set object to be SD
+    ldr r2, [r0, #8]  ; Get sector to read
+    cmp r2, #0  ; For GW compatibility, see if we're trying to read the ncsd header (sector 0)
+
+    ldr r3, =nand_offset
+    ldr r3, [r3]
+    add r2, r3  ; Add the offset to the NAND in the SD.
+
+    ldreq r3, =ncsd_header_offset
+    ldreq r3, [r3]
+    addeq r2, r3  ; If we're reading the ncsd header, add the offset of that sector.
+
+    str r2, [r0, #8]  ; Store sector to read
+
+    nand_sd_ret:
+        ; Restore registers.
+        mov r1, r5
+        mov r2, r7
+        mov r3, r6
+
+        ; Return 4 bytes behind where we got called,
+        ;   due to the offset of this function being stored there.
+        mov r0, lr
+        add r0, #4
+        bx r0
 .pool
-orig_sector:		.word 0x00000000
-orig_ptr:			.word 0x00000000
 nand_offset:		.ascii "NAND"       ; for rednand this should be 1
 ncsd_header_offset:	.ascii "NCSD"       ; depends on nand manufacturer + emunand type (GW/RED)
-;ncsd_header_offset: .word 0x1D7800
-;ncsd_header_offset: .word 0x1DD000
-slot0x25keyX:
-    .word 0xABD8E7CE 
-    .word 0xAE0DC030 
-    .word 0xE3F50E85 
-    .word 0xF35AAC82
 .close