import agb_sram library

12 files changed, 125 insertions, 264 deletions

diff --git a/Makefile b/Makefile
index 94bfc73..f6b6a80 100755
--- a/Makefile
+++ b/Makefile
@@ -112,6 +112,9 @@ $(C_BUILDDIR)/m4a_2.o: CC1 := tools/agbcc/bin/old_agbcc
 $(C_BUILDDIR)/m4a_4.o: CC1 := tools/agbcc/bin/old_agbcc
 $(C_BUILDDIR)/m4a.o: CC1 := tools/agbcc/bin/old_agbcc
 
+$(C_BUILDDIR)/agb_sram.o: CFLAGS := -mthumb-interwork -Wimplicit -Wparentheses -Werror -O1
+$(C_BUILDDIR)/agb_sram.o: CC1 := tools/agbcc/bin/old_agbcc
+
 ifeq ($(NODEP),)
 $(C_BUILDDIR)/%.o: c_dep = $(shell $(SCANINC) -I include $(C_SUBDIR)/$*.c)
 else
diff --git a/asm/rom_3219C.s b/asm/rom_3219C.s
index 270885e..af67f74 100755
--- a/asm/rom_3219C.s
+++ b/asm/rom_3219C.s
@@ -49099,7 +49099,7 @@ sub_4B654: @ 0x0804B654
 	str r1, [r0]
 	ldr r1, _0804B670 @ =0x0E000544
 	ldr r2, _0804B674 @ =0x00001410
-	bl sub_55654
+	bl WriteAndVerifySramFast
 	pop {r0}
 	bx r0
 	.align 2, 0
@@ -49119,7 +49119,7 @@ sub_4B678: @ 0x0804B678
 	mov r8, r0
 	cmp r0, #1
 	bne _0804B6B0
-	ldr r3, _0804B6A0 @ =gUnknown_02032FF0
+	ldr r3, _0804B6A0 @ =ReadSramFast
 	ldr r0, _0804B6A4 @ =0x0E000544
 	ldr r1, _0804B6A8 @ =gUnknown_020314E0
 	ldr r1, [r1]
@@ -49128,7 +49128,7 @@ sub_4B678: @ 0x0804B678
 	bl _call_via_r3
 	b _0804B746
 	.align 2, 0
-_0804B6A0: .4byte gUnknown_02032FF0
+_0804B6A0: .4byte ReadSramFast
 _0804B6A4: .4byte 0x0E000544
 _0804B6A8: .4byte gUnknown_020314E0
 _0804B6AC: .4byte 0x00001410
@@ -49779,7 +49779,7 @@ _0804BBCC:
 	ldr r1, _0804BC30 @ =0x0E000544
 	adds r0, r6, #0
 	movs r2, #4
-	bl sub_55654
+	bl WriteAndVerifySramFast
 _0804BC14:
 	pop {r3, r4, r5}
 	mov r8, r3
diff --git a/asm/rom_528AC.s b/asm/rom_528AC.s
index f5f2b88..171370b 100755
--- a/asm/rom_528AC.s
+++ b/asm/rom_528AC.s
@@ -189,7 +189,7 @@ _08052A14: .4byte gUnknown_08533F60
 	thumb_func_start sub_52A18
 sub_52A18: @ 0x08052A18
 	push {r4, lr}
-	bl sub_555BC
+	bl SetSramFastFunc
 	ldr r4, _08052A4C @ =gMain
 	movs r0, #0
 	strb r0, [r4, #0xc]
@@ -232,7 +232,7 @@ sub_52A68: @ 0x08052A68
 	movs r0, #0
 	mov r8, r0
 	movs r7, #0
-	ldr r1, _08052B04 @ =gUnknown_02032FF0
+	ldr r1, _08052B04 @ =ReadSramFast
 	mov sb, r1
 _08052A7A:
 	ldr r5, _08052B08 @ =gUnknown_0200B134
@@ -309,7 +309,7 @@ _08052AF0:
 	mov r8, r6
 	b _08052B22
 	.align 2, 0
-_08052B04: .4byte gUnknown_02032FF0
+_08052B04: .4byte ReadSramFast
 _08052B08: .4byte gUnknown_0200B134
 _08052B0C: .4byte 0x0E000004
 _08052B10: .4byte gUnknown_086BBA6C
@@ -377,11 +377,11 @@ _08052B6A:
 	lsls r4, r4, #2
 	adds r0, r5, #0
 	adds r2, r4, #0
-	bl sub_55654
+	bl WriteAndVerifySramFast
 	ldr r1, _08052BAC @ =0x0E0002A4
 	adds r0, r5, #0
 	adds r2, r4, #0
-	bl sub_55654
+	bl WriteAndVerifySramFast
 	pop {r4, r5}
 	pop {r0}
 	bx r0
@@ -449,11 +449,11 @@ _08052BFC:
 	lsls r4, r4, #2
 	adds r0, r6, #0
 	adds r2, r4, #0
-	bl sub_55654
+	bl WriteAndVerifySramFast
 	ldr r1, _08052C40 @ =0x0E0002A4
 	adds r0, r6, #0
 	adds r2, r4, #0
-	bl sub_55654
+	bl WriteAndVerifySramFast
 _08052C28:
 	pop {r4, r5, r6}
 	pop {r0}
@@ -468,7 +468,7 @@ _08052C40: .4byte 0x0E0002A4
 	thumb_func_start sub_52C44
 sub_52C44: @ 0x08052C44
 	push {lr}
-	ldr r2, _08052C58 @ =gUnknown_02032FF0
+	ldr r2, _08052C58 @ =ReadSramFast
 	ldr r0, _08052C5C @ =0x0E000544
 	ldr r1, _08052C60 @ =gUnknown_0200B100
 	ldr r3, [r2]
@@ -477,7 +477,7 @@ sub_52C44: @ 0x08052C44
 	pop {r0}
 	bx r0
 	.align 2, 0
-_08052C58: .4byte gUnknown_02032FF0
+_08052C58: .4byte ReadSramFast
 _08052C5C: .4byte 0x0E000544
 _08052C60: .4byte gUnknown_0200B100
 
diff --git a/asm/unknown_lib.s b/asm/unknown_lib.s
deleted file mode 100755
index a96898d..0000000
--- a/asm/unknown_lib.s
+++ /dev/null
@@ -1,230 +0,0 @@
-	.include "asm/macros.inc"
-	.include "constants/gba_constants.inc"
-
-	@ extern
-
-	.syntax unified
-
-	.text
-
-	thumb_func_start sub_554F0
-sub_554F0: @ 0x080554F0
-	push {r4, r5, lr}
-	adds r5, r0, #0
-	adds r4, r1, #0
-	adds r3, r2, #0
-	ldr r2, _08055528 @ =0x04000204
-	ldrh r0, [r2]
-	ldr r1, _0805552C @ =0x0000FFFC
-	ands r0, r1
-	movs r1, #3
-	orrs r0, r1
-	strh r0, [r2]
-	subs r3, #1
-	movs r0, #1
-	rsbs r0, r0, #0
-	cmp r3, r0
-	beq _08055520
-	adds r1, r0, #0
-_08055512:
-	ldrb r0, [r5]
-	strb r0, [r4]
-	adds r5, #1
-	adds r4, #1
-	subs r3, #1
-	cmp r3, r1
-	bne _08055512
-_08055520:
-	pop {r4, r5}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_08055528: .4byte 0x04000204
-_0805552C: .4byte 0x0000FFFC
-
-	thumb_func_start sub_55530
-sub_55530: @ 0x08055530
-	push {r4, r5, lr}
-	adds r5, r0, #0
-	adds r4, r1, #0
-	adds r3, r2, #0
-	ldr r2, _08055568 @ =0x04000204
-	ldrh r0, [r2]
-	ldr r1, _0805556C @ =0x0000FFFC
-	ands r0, r1
-	movs r1, #3
-	orrs r0, r1
-	strh r0, [r2]
-	subs r3, #1
-	movs r0, #1
-	rsbs r0, r0, #0
-	cmp r3, r0
-	beq _08055560
-	adds r1, r0, #0
-_08055552:
-	ldrb r0, [r5]
-	strb r0, [r4]
-	adds r5, #1
-	adds r4, #1
-	subs r3, #1
-	cmp r3, r1
-	bne _08055552
-_08055560:
-	pop {r4, r5}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_08055568: .4byte 0x04000204
-_0805556C: .4byte 0x0000FFFC
-
-	thumb_func_start sub_55570
-sub_55570: @ 0x08055570
-	push {r4, r5, lr}
-	adds r5, r0, #0
-	adds r4, r1, #0
-	adds r3, r2, #0
-	ldr r2, _080555A4 @ =0x04000204
-	ldrh r0, [r2]
-	ldr r1, _080555A8 @ =0x0000FFFC
-	ands r0, r1
-	movs r1, #3
-	orrs r0, r1
-	strh r0, [r2]
-	subs r3, #1
-	movs r0, #1
-	rsbs r0, r0, #0
-	cmp r3, r0
-	beq _080555B2
-	adds r2, r0, #0
-_08055592:
-	ldrb r1, [r4]
-	ldrb r0, [r5]
-	adds r5, #1
-	adds r4, #1
-	cmp r1, r0
-	beq _080555AC
-	subs r0, r4, #1
-	b _080555B4
-	.align 2, 0
-_080555A4: .4byte 0x04000204
-_080555A8: .4byte 0x0000FFFC
-_080555AC:
-	subs r3, #1
-	cmp r3, r2
-	bne _08055592
-_080555B2:
-	movs r0, #0
-_080555B4:
-	pop {r4, r5}
-	pop {r1}
-	bx r1
-
-	thumb_func_start sub_555BC
-sub_555BC: @ 0x080555BC
-	ldr r2, _080555D0 @ =sub_554F0
-	movs r0, #1
-	eors r2, r0
-	ldr r3, _080555D4 @ =gUnknown_02002FD8
-	ldr r0, _080555D8 @ =sub_55530
-	ldr r1, _080555D0 @ =sub_554F0
-	subs r0, r0, r1
-	lsls r0, r0, #0xf
-	b _080555E8
-	.align 2, 0
-_080555D0: .4byte sub_554F0
-_080555D4: .4byte gUnknown_02002FD8
-_080555D8: .4byte sub_55530
-_080555DC:
-	ldrh r0, [r2]
-	strh r0, [r3]
-	adds r2, #2
-	adds r3, #2
-	subs r0, r1, #1
-	lsls r0, r0, #0x10
-_080555E8:
-	lsrs r1, r0, #0x10
-	cmp r1, #0
-	bne _080555DC
-	ldr r1, _08055608 @ =gUnknown_02032FF0
-	ldr r0, _0805560C @ =gUnknown_02002FD9
-	str r0, [r1]
-	ldr r2, _08055610 @ =sub_55570
-	movs r0, #1
-	eors r2, r0
-	ldr r3, _08055614 @ =gUnknown_02002F38
-	ldr r0, _08055618 @ =sub_555BC
-	ldr r1, _08055610 @ =sub_55570
-	subs r0, r0, r1
-	lsls r0, r0, #0xf
-	b _08055628
-	.align 2, 0
-_08055608: .4byte gUnknown_02032FF0
-_0805560C: .4byte gUnknown_02002FD9
-_08055610: .4byte sub_55570
-_08055614: .4byte gUnknown_02002F38
-_08055618: .4byte sub_555BC
-_0805561C:
-	ldrh r0, [r2]
-	strh r0, [r3]
-	adds r2, #2
-	adds r3, #2
-	subs r0, r1, #1
-	lsls r0, r0, #0x10
-_08055628:
-	lsrs r1, r0, #0x10
-	cmp r1, #0
-	bne _0805561C
-	ldr r1, _08055644 @ =gUnknown_02032FF4
-	ldr r0, _08055648 @ =gUnknown_02002F39
-	str r0, [r1]
-	ldr r2, _0805564C @ =0x04000204
-	ldrh r0, [r2]
-	ldr r1, _08055650 @ =0x0000FFFC
-	ands r0, r1
-	movs r1, #3
-	orrs r0, r1
-	strh r0, [r2]
-	bx lr
-	.align 2, 0
-_08055644: .4byte gUnknown_02032FF4
-_08055648: .4byte gUnknown_02002F39
-_0805564C: .4byte 0x04000204
-_08055650: .4byte 0x0000FFFC
-
-	thumb_func_start sub_55654
-sub_55654: @ 0x08055654
-	push {r4, r5, r6, r7, lr}
-	adds r6, r0, #0
-	adds r5, r1, #0
-	adds r4, r2, #0
-	movs r7, #0
-	b _08055666
-_08055660:
-	adds r0, r7, #1
-	lsls r0, r0, #0x18
-	lsrs r7, r0, #0x18
-_08055666:
-	cmp r7, #2
-	bhi _08055688
-	adds r0, r6, #0
-	adds r1, r5, #0
-	adds r2, r4, #0
-	bl sub_55530
-	ldr r0, _08055690 @ =gUnknown_02032FF4
-	ldr r3, [r0]
-	adds r0, r6, #0
-	adds r1, r5, #0
-	adds r2, r4, #0
-	bl _call_via_r3
-	adds r3, r0, #0
-	cmp r3, #0
-	bne _08055660
-_08055688:
-	adds r0, r3, #0
-	pop {r4, r5, r6, r7}
-	pop {r1}
-	bx r1
-	.align 2, 0
-_08055690: .4byte gUnknown_02032FF4
-
-	.align 2, 0 @ Don't pad with nop.
diff --git a/include/agb_sram.h b/include/agb_sram.h
new file mode 100644
index 0000000..c609417
--- /dev/null
+++ b/include/agb_sram.h
@@ -0,0 +1,10 @@
+#ifndef GUARD_AGB_SRAM_H
+#define GUARD_AGB_SRAM_H
+
+void SetSramFastFunc(void);
+void WriteSramFast(const u8 *src, u8 *dest, u32 size);
+extern void (*ReadSramFast)(const u8 *src, u8 *dest, u32 size);
+extern u32 (*VerifySramFast)(const u8 *src, u8 *dest, u32 size);
+u32 WriteAndVerifySramFast(const u8 *src, u8 *dest, u32 size);
+
+#endif  // GUARD_AGB_SRAM_H
\ No newline at end of file
diff --git a/include/functions.h b/include/functions.h
index d6e53d8..c1d64cf 100644
--- a/include/functions.h
+++ b/include/functions.h
@@ -834,12 +834,4 @@ extern void sub_11B74(void);
 
 extern int sub_55A24(u8*); // Rumble Pak?
 
-// asm/unknown_lib.s
-
-//extern ? sub_554F0();
-//extern ? sub_55530();
-//extern ? sub_55570();
-//extern ? sub_555BC();
-extern void sub_55654(void *, u32, int);
-
 #endif  // GUARD_FUNCTIONS_H
\ No newline at end of file
diff --git a/ld_script.txt b/ld_script.txt
index 5e3b51a..6254b5a 100755
--- a/ld_script.txt
+++ b/ld_script.txt
@@ -50,7 +50,7 @@ SECTIONS
         asm/m4a_1.o(.text);
         src/m4a.o(.text);
         asm/libagbsyscall.o(.text);
-        asm/unknown_lib.o(.text);
+        src/agb_sram.o(.text);
         *libgcc.a:_call_via_rX.o(.text);
         *libgcc.a:_divsi3.o(.text);
         *libgcc.a:_dvmd_tls.o(.text);
diff --git a/libagbbackup.a b/libagbbackup.a
new file mode 100644
index 0000000..33163d7
--- /dev/null
+++ b/libagbbackup.a
diff --git a/src/agb_sram.c b/src/agb_sram.c
new file mode 100644
index 0000000..e58d5fa
--- /dev/null
+++ b/src/agb_sram.c
@@ -0,0 +1,89 @@
+#include "global.h"
+#include "agb_sram.h"
+
+static u16 verifySramFast_Work[80]; // buffer to hold code of VerifySramFast_Core
+static u16 readSramFast_Work[64];  // buffer to hold code of ReadSramFast_Core
+
+u32 (*VerifySramFast)(const u8 *src, u8 *dest, u32 size);  // pointer to verifySramFast_Work
+void (*ReadSramFast)(const u8 *src, u8 *dest, u32 size);  // pointer to readSramFast_Work
+
+void ReadSramFast_Core(const u8 *src, u8 *dest, u32 size)
+{
+    REG_WAITCNT = (REG_WAITCNT & ~3) | 3;
+    while (--size != -1)
+        *dest++ = *src++;
+}
+
+void WriteSramFast(const u8 *src, u8 *dest, u32 size)
+{
+    REG_WAITCNT = (REG_WAITCNT & ~3) | 3;
+    while (--size != -1)
+        *dest++ = *src++;
+}
+
+u32 VerifySramFast_Core(const u8 *src, u8 *dest, u32 size)
+{
+    REG_WAITCNT = (REG_WAITCNT & ~3) | 3;
+    while (--size != -1)
+    {
+        if (*dest++ != *src++)
+            return (u32)(dest - 1);
+    }
+    return 0;
+}
+
+void SetSramFastFunc(void)
+{
+    u16 *src;
+    u16 *dest;
+    u16 size;
+
+    src = (u16 *)ReadSramFast_Core;
+    // clear the least significant bit so that we get the actual start address of the function
+    src = (u16 *)((uintptr_t)src ^ 1);  // NOTE: In Fire Emblem 8, this is '& ~1' instead of '^ 1'.
+    dest = readSramFast_Work;
+    // get the size of the function by subtracting the address of the next function
+    size = ((uintptr_t)WriteSramFast - (uintptr_t)ReadSramFast_Core) / 2;
+    // copy the function into the WRAM buffer
+    while (size != 0)
+    {
+        *dest++ = *src++;
+        size--;
+    }
+    // add 1 to the address of the buffer so that we stay in THUMB mode when bx-ing to the address
+    ReadSramFast = (void *)((uintptr_t)readSramFast_Work + 1);
+
+    src = (u16 *)VerifySramFast_Core;
+    // clear the least significant bit so that we get the actual start address of the function
+    src = (u16 *)((uintptr_t)src ^ 1);  // NOTE: In Fire Emblem 8, this is '& ~1' instead of '^ 1'.
+    dest = verifySramFast_Work;
+    // get the size of the function by subtracting the address of the next function
+    size = ((uintptr_t)SetSramFastFunc - (uintptr_t)VerifySramFast_Core) / 2;
+    // copy the function into the WRAM buffer
+    while (size != 0)
+    {
+        *dest++ = *src++;
+        size--;
+    }
+    // add 1 to the address of the buffer so that we stay in THUMB mode when bx-ing to the address
+    VerifySramFast = (void *)((uintptr_t)verifySramFast_Work + 1);
+
+    REG_WAITCNT = (REG_WAITCNT & ~3) | 3;
+}
+
+u32 WriteAndVerifySramFast(const u8 *src, u8 *dest, u32 size)
+{
+    u8 i;
+    u32 errorAddr;
+
+    // try writing and verifying the data 3 times
+    for (i = 0; i < 3; i++)
+    {
+        WriteSramFast(src, dest, size);
+        errorAddr = VerifySramFast(src, dest, size);
+        if (errorAddr == 0)
+            break;
+    }
+
+    return errorAddr;
+}
diff --git a/src/titlescreen.c b/src/titlescreen.c
index a4e75e7..6a2bcac 100755
--- a/src/titlescreen.c
+++ b/src/titlescreen.c
@@ -1,6 +1,7 @@
 #include "global.h"
-#include "titlescreen.h"
+#include "agb_sram.h"
 #include "m4a.h"
+#include "titlescreen.h"
 #include "main.h"
 
 static void sub_114FC(void);
@@ -852,5 +853,5 @@ void sub_11B74(void)
     sub_52C64();
     sub_52B30();
     gMain.unk40 = 0;
-    sub_55654(&gMain.unk40, 0x0E000544 /* Possibly SRAM address */, 4);
+    WriteAndVerifySramFast((const u8 *)&gMain.unk40, (void *)0x0E000544, 4);
 }
diff --git a/sym_common.txt b/sym_common.txt
index 93b48cf..433c13b 100755
--- a/sym_common.txt
+++ b/sym_common.txt
@@ -2,8 +2,8 @@
 
 gUnknown_02032FB0: @ 0x02032FB0
 	.space 0x40
-gUnknown_02032FF0: @ 0x02032FF0
+ReadSramFast: @ 0x02032FF0
 	.space 0x4
-gUnknown_02032FF4: @ 0x02032FF4
+VerifySramFast: @ 0x02032FF4
 	.space 0xF7C08C
 gUnknown_02FAF080: @ 0x02FAF080
diff --git a/sym_ewram.txt b/sym_ewram.txt
index 88ea13f..22057c0 100644
--- a/sym_ewram.txt
+++ b/sym_ewram.txt
@@ -84,14 +84,10 @@ gUnknown_0200293A: @ 0x0200293A
 	.space 0x1E
 gUnknown_02002958: @ 0x2002958
 	.space 0x5E0
-gUnknown_02002F38: @ 0x02002F38
-	.space 0x1
-gUnknown_02002F39: @ 0x02002F39
-	.space 0x9F
-gUnknown_02002FD8: @ 0x02002FD8
-	.space 0x1
-gUnknown_02002FD9: @ 0x02002FD9
-	.space 0x87
+verifySramFast_Work: @ 0x02002F38
+	.space 0xA0
+readSramFast_Work: @ 0x02002FD8
+	.space 0x88
 gIntrTable: @ 0x2003060
 	.space 0x40
 gUnknown_020030A0: @ 0x020030A0