decompile some of file_system

asm/file_system.s

@@ -5,198 +5,6 @@
 
 	.text
 
-	thumb_func_start InitFileSystem
-InitFileSystem:
-	push {r4,lr}
-	ldr r3, _0800A8EC
-	ldr r4, _0800A8F0
-	movs r2, 0
-	ldr r0, _0800A8F4
-	movs r1, 0x3F
-_0800A8D0:
-	str r2, [r0]
-	str r2, [r0, 0x4]
-	adds r0, 0x8
-	subs r1, 0x1
-	cmp r1, 0
-	bge _0800A8D0
-	movs r0, 0
-	str r0, [r3]
-	movs r0, 0x1
-	str r0, [r4]
-	pop {r4}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_0800A8EC: .4byte gUnknown_203B094
-_0800A8F0: .4byte gUnknown_202D2A4
-_0800A8F4: .4byte gUnknown_202D2A8
-	thumb_func_end InitFileSystem
-
-	thumb_func_start sub_800A8F8
-sub_800A8F8:
-	ldr r1, _0800A904
-	ldr r2, [r1]
-	str r0, [r1]
-	adds r0, r2, 0
-	bx lr
-	.align 2, 0
-_0800A904: .4byte gUnknown_202D2A4
-	thumb_func_end sub_800A8F8
-
-	thumb_func_start OpenFile
-OpenFile:
-	push {r4-r7,lr}
-	mov r7, r8
-	push {r7}
-	sub sp, 0x12C
-	mov r8, r0
-	adds r4, r1, 0
-	ldr r1, _0800A93C
-	adds r0, r4, 0
-	bl strcmp
-	cmp r0, 0
-	beq _0800A922
-	movs r0, 0x1
-_0800A922:
-	movs r1, 0
-	lsls r0, 24
-	cmp r0, 0
-	bne _0800A92C
-	movs r1, 0x1
-_0800A92C:
-	cmp r1, 0
-	beq _0800A9B6
-	ldr r7, [r4, 0xC]
-	movs r6, 0
-	ldr r0, [r4, 0x8]
-	subs r5, r0, 0x1
-	b _0800A94A
-	.align 2, 0
-_0800A93C: .4byte gUnknown_80B9B94
-_0800A940:
-	cmp r0, 0
-	bge _0800A948
-	adds r6, r4, 0x1
-	b _0800A94A
-_0800A948:
-	adds r5, r4, 0
-_0800A94A:
-	cmp r6, r5
-	bge _0800A968
-	adds r0, r6, r5
-	lsrs r1, r0, 31
-	adds r0, r1
-	asrs r4, r0, 1
-	lsls r0, r4, 3
-	adds r0, r7
-	ldr r0, [r0]
-	mov r1, r8
-	bl strcmp
-	cmp r0, 0
-	bne _0800A940
-	adds r6, r4, 0
-_0800A968:
-	lsls r0, r6, 3
-	adds r6, r7, r0
-	ldr r0, [r6]
-	mov r1, r8
-	bl strcmp
-	cmp r0, 0
-	beq _0800A994
-	ldr r1, _0800A984
-	mov r0, sp
-	mov r2, r8
-	bl sprintf
-	b _0800A9B6
-	.align 2, 0
-_0800A984: .4byte gUnknown_80B9B9C
-_0800A988:
-	str r6, [r2]
-	adds r0, r7, 0x4
-	adds r0, r3, r0
-	str r1, [r0]
-	adds r0, r2, 0
-	b _0800A9B8
-_0800A994:
-	ldr r0, _0800A9C4
-	ldr r0, [r0]
-	movs r4, 0
-	ldr r5, _0800A9C8
-	adds r7, r5, 0
-_0800A99E:
-	adds r0, 0x1
-	cmp r0, 0x3F
-	ble _0800A9A6
-	movs r0, 0
-_0800A9A6:
-	lsls r3, r0, 3
-	adds r2, r3, r5
-	ldr r1, [r2]
-	cmp r1, 0
-	beq _0800A988
-	adds r4, 0x1
-	cmp r4, 0x3F
-	ble _0800A99E
-_0800A9B6:
-	movs r0, 0
-_0800A9B8:
-	add sp, 0x12C
-	pop {r3}
-	mov r8, r3
-	pop {r4-r7}
-	pop {r1}
-	bx r1
-	.align 2, 0
-_0800A9C4: .4byte gUnknown_203B094
-_0800A9C8: .4byte gUnknown_202D2A8
-	thumb_func_end OpenFile
-
-	thumb_func_start GetFileDataPtrFromFileEntry
-GetFileDataPtrFromFileEntry:
-	ldr r1, [r0]
-	ldr r1, [r1, 0x4]
-	str r1, [r0, 0x4]
-	adds r0, r1, 0
-	bx lr
-	thumb_func_end GetFileDataPtrFromFileEntry
-
-	thumb_func_start GetFileDataPtr
-GetFileDataPtr:
-	push {r4,lr}
-	adds r4, r0, 0
-	bl GetFileDataPtrFromFileEntry
-	adds r0, r4, 0
-	bl GetSiroPtr
-	pop {r4}
-	pop {r1}
-	bx r1
-	thumb_func_end GetFileDataPtr
-
-	thumb_func_start OpenFileAndGetFileDataPtr
-OpenFileAndGetFileDataPtr:
-	push {r4,lr}
-	bl OpenFile
-	adds r4, r0, 0
-	cmp r4, 0
-	beq _0800A9FE
-	movs r1, 0
-	bl GetFileDataPtr
-_0800A9FE:
-	adds r0, r4, 0
-	pop {r4}
-	pop {r1}
-	bx r1
-	thumb_func_end OpenFileAndGetFileDataPtr
-
-	thumb_func_start Call_OpenFileAndGetFileDataPtr
-Call_OpenFileAndGetFileDataPtr:
-	push {lr}
-	bl OpenFileAndGetFileDataPtr
-	pop {r1}
-	bx r1
-	thumb_func_end Call_OpenFileAndGetFileDataPtr
-
 	thumb_func_start CloseFile
 CloseFile:
 	push {r4,r5,lr}

ld_script.txt

@@ -49,6 +49,7 @@ SECTIONS {
         src/random.o(.text);
         asm/text.o(.text);
         asm/code_8009804.o(.text);
+        src/file_system.o(.text);
         asm/file_system.o(.text);
         asm/code_800AAA0.o(.text);
         src/main.o(.text);
@@ -81,6 +82,8 @@ SECTIONS {
     ALIGN(4)
     {
         data/data.o(.rodata);
+        src/file_system.o(.rodata);
+        data/data_80B9BB8.o(.rodata);
         src/agb_flash.o(.rodata);
         src/agb_flash_1m.o(.rodata);
         src/agb_flash_mx.o(.rodata);

src/file_system.c

@@ -0,0 +1,145 @@
+#include "global.h"
+
+struct File
+{
+    char *name;
+    u8 *data;
+};
+
+struct OpenedFile
+{
+    struct File *file;
+    u8 *data;
+};
+
+struct FileArchive
+{
+    char magic[8];
+    s32 count;
+    struct File *entries;
+};
+
+extern struct OpenedFile gUnknown_202D2A8[];
+
+extern u32 gUnknown_203B094;
+extern u32 gUnknown_202D2A4;
+
+extern int sprintf(char *, const char *, ...);
+
+u8 *GetSiroPtr(struct OpenedFile *);
+
+void InitFileSystem(void)
+{
+    s32 i;
+
+    for (i = 0; i < 64; i++)
+    {
+        gUnknown_202D2A8[i].file = NULL;
+        gUnknown_202D2A8[i].data = NULL;
+    }
+
+    gUnknown_203B094 = 0;
+    gUnknown_202D2A4 = 1;
+}
+
+u32 sub_800A8F8(u32 value)
+{
+    u32 oldValue = gUnknown_202D2A4;
+    gUnknown_202D2A4 = value;
+    return oldValue;
+}
+
+struct OpenedFile *OpenFile(char *filename, struct FileArchive *arc)
+{
+    char buffer[0x12C];
+    s32 left, right;
+    s32 cursor;
+    s32 i;
+    s32 magic = 0;
+    s32 magicFound;
+    struct File *entries;
+    struct File *file;
+
+    magic = strcmp(arc->magic, "pksdir0") != 0;
+
+    magicFound = 0;
+
+    if (!(u8)magic)
+        magicFound = 1;
+
+    if (!magicFound)
+        return NULL;
+
+    entries = arc->entries;
+    left = 0;
+    right = arc->count - 1;
+
+    while (left < right)
+    {
+        s32 mid = (left + right) / 2;
+        int result = strcmp(entries[mid].name, filename);
+        if (result == 0)
+        {
+            left = mid;
+            break;
+        }
+        else if (result < 0)
+        {
+            left = mid + 1;
+        }
+        else
+        {
+            right = mid;
+        }
+    }
+
+    file = &entries[left];
+
+    if (strcmp(file->name, filename))
+    {
+        sprintf(buffer, "not find file [%s]\n", filename);
+        return NULL;
+    }
+
+    cursor = gUnknown_203B094;
+
+    for (i = 0; i < 64; i++)
+    {
+        cursor++;
+        if (cursor > 63)
+            cursor = 0;
+        if (!gUnknown_202D2A8[cursor].file)
+        {
+            gUnknown_202D2A8[cursor].file = file;
+            gUnknown_202D2A8[cursor].data = NULL;
+            return &gUnknown_202D2A8[cursor];
+        }
+    }
+
+    return NULL;
+}
+
+static u8 *_GetFileDataPtr(struct OpenedFile *openedFile)
+{
+    openedFile->data = openedFile->file->data;
+    return openedFile->data;
+}
+
+u8 *GetFileDataPtr(struct OpenedFile *openedFile, int unused)
+{
+    _GetFileDataPtr(openedFile);
+    return GetSiroPtr(openedFile);
+}
+
+struct OpenedFile *OpenFileAndGetFileDataPtr(char *filename, struct FileArchive *arc)
+{
+    struct OpenedFile *openedFile = OpenFile(filename, arc);
+    if (openedFile)
+        GetFileDataPtr(openedFile, 0);
+    return openedFile;
+}
+
+struct OpenedFile *Call_OpenFileAndGetFileDataPtr(char *filename, struct FileArchive *arc)
+{
+    return OpenFileAndGetFileDataPtr(filename, arc);
+}