Merge pull request #261 from Chesyon/bitstreams

Decomp CopyMove(set)To/FromStream
2026-08-28 13:50:45 -05:00 · 2026-05-06 21:26:47 -04:00
parent f689755365 ac8d45ad2f
commit 4bd8ed6ee9
19 changed files with 338 additions and 353 deletions
--- a/asm/include/main_02013C30.inc
+++ b/asm/include/main_02013C30.inc
@@ -1,10 +1,6 @@
 #pragma once
-.public _s32_div_f
-.public CopyBitsFrom
-.public CopyBitsTo
 .public DUNGEON_MOVE_TABLES
 .public GetInfoMoveGround
-.public memset
-.public Rand16Bit
 .public RECOIL_MOVE_LIST
-.public StringFromId
+.public Rand16Bit
+.public _s32_div_f
--- a/asm/include/main_02014B1C.inc
+++ b/asm/include/main_02014B1C.inc
@@ -0,0 +1,4 @@
+#pragma once
+.public CopyBitsFrom
+.public CopyBitsTo
+.public memset
--- a/asm/include/overlay_01.inc
+++ b/asm/include/overlay_01.inc
@@ -23,8 +23,8 @@
 .public Copy16BitsTo
 .public CopyBitsFrom
 .public CopyBitsTo
-.public CopyMovesetFrom
-.public CopyMovesetTo
+.public CopyMovesetFromStream
+.public CopyMovesetToStream
 .public CreateAdvancedMenu
 .public CreateAdvancedTextBox
 .public CreateControlsChart
--- a/asm/main_02013C30.s
+++ b/asm/main_02013C30.s
@@ -1073,173 +1073,3 @@ _02014A3C:
 	mov r0, r2
 	ldmia sp!, {r3, r4, r5, r6, r7, pc}
 	arm_func_end sub_020149C0
-
-	arm_func_start CopyMoveTo
-CopyMoveTo: ; 0x02014A4C
-	stmdb sp!, {r3, r4, r5, lr}
-	mov r5, r0
-	mov r4, r1
-	mov r2, #4
-	bl CopyBitsTo
-	mov r0, r5
-	add r1, r4, #2
-	mov r2, #0xa
-	bl CopyBitsTo
-	mov r0, r5
-	add r1, r4, #4
-	mov r2, #7
-	bl CopyBitsTo
-	ldmia sp!, {r3, r4, r5, pc}
-	arm_func_end CopyMoveTo
-
-	arm_func_start CopyMoveFrom
-CopyMoveFrom: ; 0x02014A84
-	stmdb sp!, {r3, r4, r5, lr}
-	mov r5, r0
-	mov r4, r1
-	mov r2, #4
-	bl CopyBitsFrom
-	mov r0, r5
-	add r1, r4, #2
-	mov r2, #0xa
-	bl CopyBitsFrom
-	mov r0, r5
-	add r1, r4, #4
-	mov r2, #7
-	bl CopyBitsFrom
-	ldmia sp!, {r3, r4, r5, pc}
-	arm_func_end CopyMoveFrom
-
-	arm_func_start CopyMovesetTo
-CopyMovesetTo: ; 0x02014ABC
-	stmdb sp!, {r3, r4, r5, r6, r7, lr}
-	mov r7, r0
-	mov r6, r1
-	mov r5, #0
-	mov r4, #6
-_02014AD0:
-	mla r1, r5, r4, r6
-	mov r0, r7
-	bl CopyMoveTo
-	add r5, r5, #1
-	cmp r5, #4
-	blt _02014AD0
-	ldmia sp!, {r3, r4, r5, r6, r7, pc}
-	arm_func_end CopyMovesetTo
-
-	arm_func_start CopyMovesetFrom
-CopyMovesetFrom: ; 0x02014AEC
-	stmdb sp!, {r3, r4, r5, r6, r7, lr}
-	mov r7, r0
-	mov r6, r1
-	mov r5, #0
-	mov r4, #6
-_02014B00:
-	mla r1, r5, r4, r6
-	mov r0, r7
-	bl CopyMoveFrom
-	add r5, r5, #1
-	cmp r5, #4
-	blt _02014B00
-	ldmia sp!, {r3, r4, r5, r6, r7, pc}
-	arm_func_end CopyMovesetFrom
-
-	arm_func_start sub_02014B1C
-sub_02014B1C: ; 0x02014B1C
-	stmdb sp!, {r3, r4, r5, lr}
-	mov r5, r0
-	mov r4, r1
-	mov r2, #4
-	bl CopyBitsTo
-	mov r0, r5
-	add r1, r4, #2
-	mov r2, #1
-	bl CopyBitsTo
-	mov r0, r5
-	add r1, r4, #4
-	mov r2, #0xa
-	bl CopyBitsTo
-	mov r0, r5
-	add r1, r4, #6
-	mov r2, #7
-	bl CopyBitsTo
-	mov r0, r5
-	add r1, r4, #7
-	mov r2, #7
-	bl CopyBitsTo
-	ldmia sp!, {r3, r4, r5, pc}
-	arm_func_end sub_02014B1C
-
-	arm_func_start sub_02014B74
-sub_02014B74: ; 0x02014B74
-	stmdb sp!, {r4, r5, r6, lr}
-	mov r6, r0
-	mov r5, r1
-	mov r4, #0
-_02014B84:
-	mov r0, r6
-	add r1, r5, r4, lsl #3
-	bl sub_02014B1C
-	add r4, r4, #1
-	cmp r4, #4
-	blt _02014B84
-	mov r0, r6
-	add r1, r5, #0x20
-	mov r2, #8
-	bl CopyBitsTo
-	ldmia sp!, {r4, r5, r6, pc}
-	arm_func_end sub_02014B74
-
-	arm_func_start sub_02014BB0
-sub_02014BB0: ; 0x02014BB0
-	stmdb sp!, {r3, r4, r5, lr}
-	mov r4, r1
-	mov r5, r0
-	mov r0, r4
-	mov r1, #0
-	mov r2, #8
-	bl memset
-	mov r0, r5
-	mov r1, r4
-	mov r2, #4
-	bl CopyBitsFrom
-	mov r0, r5
-	add r1, r4, #2
-	mov r2, #1
-	bl CopyBitsFrom
-	mov r0, r5
-	add r1, r4, #4
-	mov r2, #0xa
-	bl CopyBitsFrom
-	mov r0, r5
-	add r1, r4, #6
-	mov r2, #7
-	bl CopyBitsFrom
-	mov r0, r5
-	add r1, r4, #7
-	mov r2, #7
-	bl CopyBitsFrom
-	ldmia sp!, {r3, r4, r5, pc}
-	arm_func_end sub_02014BB0
-
-	arm_func_start sub_02014C20
-sub_02014C20: ; 0x02014C20
-	stmdb sp!, {r4, r5, r6, lr}
-	mov r6, r0
-	mov r5, r1
-	mov r4, #0
-_02014C30:
-	mov r0, r6
-	add r1, r5, r4, lsl #3
-	bl sub_02014BB0
-	add r4, r4, #1
-	cmp r4, #4
-	blt _02014C30
-	mov r3, #0
-	mov r0, r6
-	add r1, r5, #0x20
-	mov r2, #8
-	strb r3, [r5, #0x20]
-	bl CopyBitsFrom
-	ldmia sp!, {r4, r5, r6, pc}
-	arm_func_end sub_02014C20
--- a/asm/main_02014B1C.s
+++ b/asm/main_02014B1C.s
@@ -0,0 +1,104 @@
+	.include "asm/macros.inc"
+	.include "main_02014B1C.inc"
+
+	.text
+
+	arm_func_start sub_02014B1C
+sub_02014B1C: ; 0x02014B1C
+	stmdb sp!, {r3, r4, r5, lr}
+	mov r5, r0
+	mov r4, r1
+	mov r2, #4
+	bl CopyBitsTo
+	mov r0, r5
+	add r1, r4, #2
+	mov r2, #1
+	bl CopyBitsTo
+	mov r0, r5
+	add r1, r4, #4
+	mov r2, #0xa
+	bl CopyBitsTo
+	mov r0, r5
+	add r1, r4, #6
+	mov r2, #7
+	bl CopyBitsTo
+	mov r0, r5
+	add r1, r4, #7
+	mov r2, #7
+	bl CopyBitsTo
+	ldmia sp!, {r3, r4, r5, pc}
+	arm_func_end sub_02014B1C
+
+	arm_func_start sub_02014B74
+sub_02014B74: ; 0x02014B74
+	stmdb sp!, {r4, r5, r6, lr}
+	mov r6, r0
+	mov r5, r1
+	mov r4, #0
+_02014B84:
+	mov r0, r6
+	add r1, r5, r4, lsl #3
+	bl sub_02014B1C
+	add r4, r4, #1
+	cmp r4, #4
+	blt _02014B84
+	mov r0, r6
+	add r1, r5, #0x20
+	mov r2, #8
+	bl CopyBitsTo
+	ldmia sp!, {r4, r5, r6, pc}
+	arm_func_end sub_02014B74
+
+	arm_func_start sub_02014BB0
+sub_02014BB0: ; 0x02014BB0
+	stmdb sp!, {r3, r4, r5, lr}
+	mov r4, r1
+	mov r5, r0
+	mov r0, r4
+	mov r1, #0
+	mov r2, #8
+	bl memset
+	mov r0, r5
+	mov r1, r4
+	mov r2, #4
+	bl CopyBitsFrom
+	mov r0, r5
+	add r1, r4, #2
+	mov r2, #1
+	bl CopyBitsFrom
+	mov r0, r5
+	add r1, r4, #4
+	mov r2, #0xa
+	bl CopyBitsFrom
+	mov r0, r5
+	add r1, r4, #6
+	mov r2, #7
+	bl CopyBitsFrom
+	mov r0, r5
+	add r1, r4, #7
+	mov r2, #7
+	bl CopyBitsFrom
+	ldmia sp!, {r3, r4, r5, pc}
+	arm_func_end sub_02014BB0
+
+	arm_func_start sub_02014C20
+sub_02014C20: ; 0x02014C20
+	stmdb sp!, {r4, r5, r6, lr}
+	mov r6, r0
+	mov r5, r1
+	mov r4, #0
+_02014C30:
+	mov r0, r6
+	add r1, r5, r4, lsl #3
+	bl sub_02014BB0
+	add r4, r4, #1
+	cmp r4, #4
+	blt _02014C30
+	mov r3, #0
+	mov r0, r6
+	add r1, r5, #0x20
+	mov r2, #8
+	strb r3, [r5, #0x20]
+	bl CopyBitsFrom
+	ldmia sp!, {r4, r5, r6, pc}
+	arm_func_end sub_02014C20
--- a/asm/overlay_01.s
+++ b/asm/overlay_01.s
@@ -6245,7 +6245,7 @@ ov01_0232E334: ; 0x0232E334
 	bl sub_0200DFE4
 	mov r0, r7
 	add r1, r6, #0x2a
-	bl CopyMovesetTo
+	bl CopyMovesetToStream
 	add r0, sp, #0xc
 	mov r1, #0x18
 	bl MemZero
@@ -6411,7 +6411,7 @@ ov01_0232E58C: ; 0x0232E58C
 	mov r0, r6
 	add r1, r5, #0x2a
 	strh r2, [r5, #0x28]
-	bl CopyMovesetFrom
+	bl CopyMovesetFromStream
 	add r1, sp, #0
 	mov r0, r6
 	mov r2, #0xa0
--- a/include/main_02014A4C.h
+++ b/include/main_02014A4C.h
@@ -0,0 +1,11 @@
+#ifndef PMDSKY_MAIN_02014A4C_H
+#define PMDSKY_MAIN_02014A4C_H
+#include "common.h"
+#include "save.h"
+
+void CopyMoveToStream(struct bitstream * stream, struct ground_move * move );
+void CopyMoveFromStream(struct bitstream * stream, struct ground_move * move );
+void CopyMovesetToStream(struct bitstream * stream, struct ground_move * src);
+void CopyMovesetFromStream(struct bitstream * stream, struct ground_move * dst);
+
+#endif //PMDSKY_MAIN_02014A4C_H
--- a/include/main_02058FA4.h
+++ b/include/main_02058FA4.h
@@ -11,13 +11,6 @@ struct unkStruct_02058FCC {
    const u8 field_0x18[4][0x4c];
 };

-struct WriteMonsterInfoToSave_struct {
-    u32 unk0;
-    u32 unk4;
-    s32 result;
-    u32 unkC;
-};
-
 bool8 ExplorerMazeMonsterExists(void);
 void sub_02058FCC(struct unkStruct_02058FCC *ptr);
 // Returns the name of the explorer maze team. If the language of the team name is different from the
--- a/include/main_02059334.h
+++ b/include/main_02059334.h
@@ -2,9 +2,9 @@
 #define PMDSKY_MAIN_02059334_H

 #include "common.h"
-#include "main_02058FA4.h"
+#include "save.h"

-void WriteMonsterToSave(struct WriteMonsterInfoToSave_struct *write_info, struct ground_monster *monster);
-void ReadMonsterFromSave(struct WriteMonsterInfoToSave_struct *read_info, struct ground_monster *monster);
+void WriteMonsterToSave(struct bitstream *stream, struct ground_monster *monster);
+void ReadMonsterFromSave(struct bitstream *stream, struct ground_monster *monster);

 #endif //PMDSKY_MAIN_02059334_H
--- a/include/main_0205BD14.h
+++ b/include/main_0205BD14.h
@@ -1,9 +1,9 @@
 #ifndef PMDSKY_MAIN_0205BD14_H
 #define PMDSKY_MAIN_0205BD14_H

-#include "main_02058FA4.h"
 #include "main_0205B690.h"
 #include "util.h"
+#include "save.h"

 void sub_0205BD14(u32 *dest, s32 index);
 u32 sub_0205BD40(u32 val);
@@ -12,6 +12,6 @@ u8 sub_0205BD78(void);
 u32 sub_0205BD90(u32 a0);
 u32 sub_0205BD9C(u32 arg0, u32 arg1);
 u32 sub_0205BFB0(u32 p0, u32 p1);
-void sub_0205C19C(struct WriteMonsterInfoToSave_struct *arg0, struct unkStruct_020B0A54 *arg1);
+void sub_0205C19C(struct bitstream *stream, struct unkStruct_020B0A54 *arg1);

 #endif //PMDSKY_MAIN_0205BD14_H
--- a/include/main_0205C440.h
+++ b/include/main_0205C440.h
@@ -1,9 +1,9 @@
 #ifndef PMDSKY_MAIN_0205C440_H
 #define PMDSKY_MAIN_0205C440_H

-#include "main_02058FA4.h"
 #include "main_0205B690.h"
+#include "save.h"

-void sub_0205C440(struct WriteMonsterInfoToSave_struct *write_info, struct unkStruct_020B0A54 *p1);
+void sub_0205C440(struct bitstream *stream, struct unkStruct_020B0A54 *p1);

 #endif //PMDSKY_MAIN_0205C440_H
--- a/include/save.h
+++ b/include/save.h
@@ -0,0 +1,11 @@
+#ifndef PMDSKY_SAVE_H
+#define PMDSKY_SAVE_H
+
+struct bitstream {
+    char* ptr; // Current byte
+    u32 end; // End of the region the bitstream can read from / write to. Doesn't seem to do anything with this information?
+    u32 bit_idx; // Bit position in current byte
+    u32 bit_count; // Total bits this stream has used
+};
+
+#endif //PMDSKY_SAVE_H
--- a/main.lsf
+++ b/main.lsf
@@ -66,6 +66,8 @@ Static main
 	Object src/moves.o
 	Object src/moves_3.o
 	Object asm/main_02013C30.o
+	Object src/main_02014A4C.o
+	Object asm/main_02014B1C.o
 	Object src/main_02014CEC.o
 	Object asm/main_02014D18.o
 	Object src/main_020251AC.o
--- a/src/main_02014A4C.c
+++ b/src/main_02014A4C.c
@@ -0,0 +1,32 @@
+#include "main_02014A4C.h"
+
+extern void CopyBitsTo(struct bitstream *stream, void *src, u32 nbits);
+extern void CopyBitsFrom(struct bitstream *stream, void *dst, u32 nbits);
+
+void CopyMoveToStream(struct bitstream * stream, struct ground_move * src )
+{
+    CopyBitsTo(stream, &src->flags0, 4);
+    CopyBitsTo(stream, &src->id, 10);
+    CopyBitsTo(stream, &src->ginseng, 7);
+}
+
+void CopyMoveFromStream(struct bitstream * stream, struct ground_move * dst )
+{
+    CopyBitsFrom(stream, &dst->flags0, 4);
+    CopyBitsFrom(stream, &dst->id, 10);
+    CopyBitsFrom(stream, &dst->ginseng, 7);
+}
+
+void CopyMovesetToStream(struct bitstream * stream, struct ground_move * src)
+{
+    for (s32 i = 0; i < 4; i++) {
+        CopyMoveToStream(stream, &src[i]);
+    }
+}
+
+void CopyMovesetFromStream(struct bitstream * stream, struct ground_move * dst)
+{
+    for (s32 i = 0; i < 4; i++) {
+        CopyMoveFromStream(stream, &dst[i]);
+    }
+}
--- a/src/main_0204DA2C.c
+++ b/src/main_0204DA2C.c
@@ -1,15 +1,16 @@
 #include "main_0204DA2C.h"
 #include "main_0200330C.h"
+#include "save.h"

 extern u8 ARM9_UNKNOWN_TABLE__NA_209E164[];

-extern void InitBitstreamForRead(u8*, u8*, s32);
-extern void CopyBitsTo(u8* write_info, void* buf_write, s32 nbits);
-extern void BitstreamDebug(u8*);
+extern void InitBitstreamForRead(struct bitstream *stream, void* dst, s32 len);
+extern void CopyBitsTo(struct bitstream *stream, void* buf_write, s32 nbits);
+extern void BitstreamDebug(struct bitstream *stream);

 s32 sub_0204DA2C(u8* arg0, void* arg1, u8 arg2)
 {
-    u8 tmp3[16];
+    struct bitstream stream;
    u8 tmp2[54];
    u8 tmp1[34];

@@ -28,13 +29,13 @@ s32 sub_0204DA2C(u8* arg0, void* arg1, u8 arg2)

    s32 v1 = arg2 * 5;
    s32 v2 = (v1 & 7) + 7;
-    InitBitstreamForRead(tmp3, tmp1, (v1 >> 3) + (v2 >> 3));
+    InitBitstreamForRead(&stream, tmp1, (v1 >> 3) + (v2 >> 3));

    for (int i = 0; i < arg2; i++) {
-        CopyBitsTo(tmp3, &tmp2[i], 5);
+        CopyBitsTo(&stream, &tmp2[i], 5);
    }

-    BitstreamDebug(tmp3);
+    BitstreamDebug(&stream);
    MemcpySimple(arg1, tmp1, (v1 >> 3) + (v2 >> 3));
    return 1;
 }
--- a/src/main_02059060.c
+++ b/src/main_02059060.c
@@ -1,5 +1,6 @@
 #include "main_02058FA4.h"
 #include "common.h"
+#include "save.h"
 #include "main_0202593C.h"
 #include "main_02058FA4.h"

@@ -7,10 +8,10 @@ extern struct team_member_table *TEAM_MEMBER_TABLE_PTR;

 extern s32 GetLanguageType(void);
 extern void StrncpySimpleNoPadSafe(u8* dest, const u8* src, u32 n);
-extern void InitBitstreamForRead(struct WriteMonsterInfoToSave_struct *ptr, void *start_addr, u32 total_len);
-extern void WriteMonsterToSave(struct WriteMonsterInfoToSave_struct *write_info, struct ground_monster *monster);
+extern void InitBitstreamForRead(struct bitstream *ptr, void *start_addr, u32 total_len);
+extern void WriteMonsterToSave(struct bitstream *stream, struct ground_monster *monster);
 extern void CopyBitsTo(void *ctx, void *src, s32 nbits);
-extern void BitstreamDebug(struct WriteMonsterInfoToSave_struct *ptr);
+extern void BitstreamDebug(struct bitstream *ptr);

 void GetExplorerMazeTeamName(u8 *dest)
 {
@@ -53,26 +54,26 @@ struct ground_monster* GetExplorerMazeMonster(s16 entry_number)

 s32 WriteMonsterInfoToSave(void* start_addr, u32 total_len)
 {
-    struct WriteMonsterInfoToSave_struct local_struct;
+    struct bitstream stream;

-    InitBitstreamForRead(&local_struct, start_addr, total_len);
+    InitBitstreamForRead(&stream, start_addr, total_len);

    for (s32 i = 0; i < MAX_GROUND_TEAM_MEMBERS; i++)
    {
-        WriteMonsterToSave(&local_struct, &TEAM_MEMBER_TABLE_PTR->members[i]);
+        WriteMonsterToSave(&stream, &TEAM_MEMBER_TABLE_PTR->members[i]);
    }

-    CopyBitsTo(&local_struct, &TEAM_MEMBER_TABLE_PTR->field_0x9878, 64);
-    CopyBitsTo(&local_struct, &TEAM_MEMBER_TABLE_PTR->explorer_maze_team_native_language, 4);
-    CopyBitsTo(&local_struct, &TEAM_MEMBER_TABLE_PTR->field_0x9881, 4);
-    CopyBitsTo(&local_struct, &TEAM_MEMBER_TABLE_PTR->explorer_maze_team_name, 80);
+    CopyBitsTo(&stream, &TEAM_MEMBER_TABLE_PTR->field_0x9878, 64);
+    CopyBitsTo(&stream, &TEAM_MEMBER_TABLE_PTR->explorer_maze_team_native_language, 4);
+    CopyBitsTo(&stream, &TEAM_MEMBER_TABLE_PTR->field_0x9881, 4);
+    CopyBitsTo(&stream, &TEAM_MEMBER_TABLE_PTR->explorer_maze_team_name, 80);

    for (s32 i = 0; i < 4; i++)
    {
-        WriteMonsterToSave(&local_struct, &TEAM_MEMBER_TABLE_PTR->explorer_maze_monsters[i]);
+        WriteMonsterToSave(&stream, &TEAM_MEMBER_TABLE_PTR->explorer_maze_monsters[i]);
    }

-    BitstreamDebug(&local_struct);
+    BitstreamDebug(&stream);

-    return local_struct.result;
+    return stream.bit_idx;
 }
--- a/src/main_02059334.c
+++ b/src/main_02059334.c
@@ -1,52 +1,52 @@
 #include "main_02059334.h"
+#include "save.h"
+#include "main_02014A4C.h"

 extern void CopyBitsTo(void *ctx, void *src, s32 nbits);
-extern void Copy16BitsTo(void *write_info, void *buf_write);
-extern void CopyMovesetTo(struct WriteMonsterInfoToSave_struct *write_info, void *buffer_write);
+extern void Copy16BitsTo(void *stream, void *buf_write);
 extern void* memset(void *s, s32 c, u32 n);
-extern void CopyBitsFrom(void *read_info, void *buf_read, s32 nbits);
-extern void Copy16BitsFrom(void *read_info, void *buf_read);
-extern void CopyMovesetFrom(struct WriteMonsterInfoToSave_struct *read_info, void *dst);
+extern void CopyBitsFrom(void *stream, void *buf_read, s32 nbits);
+extern void Copy16BitsFrom(void *stream, void *buf_read);

-void WriteMonsterToSave(struct WriteMonsterInfoToSave_struct *write_info, struct ground_monster *monster)
+void WriteMonsterToSave(struct bitstream *stream, struct ground_monster *monster)
 {
-    CopyBitsTo(write_info, &monster->is_valid, 1);
-    CopyBitsTo(write_info, &monster->level, 7);
-    CopyBitsTo(write_info, &monster->id, 11);
-    Copy16BitsTo(write_info, &monster->joined_at);
-    CopyBitsTo(write_info, &monster->level_at_first_evo, 7);
-    CopyBitsTo(write_info, &monster->level_at_second_evo, 7);
-    CopyBitsTo(write_info, &monster->iq, 10);
-    CopyBitsTo(write_info, &monster->max_hp, 10);
-    CopyBitsTo(write_info, &monster->offensive_stats[0], 8);
-    CopyBitsTo(write_info, &monster->offensive_stats[1], 8);
-    CopyBitsTo(write_info, &monster->defensive_stats[0], 8);
-    CopyBitsTo(write_info, &monster->defensive_stats[1], 8);
-    CopyBitsTo(write_info, &monster->exp, 24);
-    CopyBitsTo(write_info, &monster->iq_skill_flags, 69);
-    CopyBitsTo(write_info, &monster->tactic, 4);
-    CopyMovesetTo(write_info, &monster->moves);
-    CopyBitsTo(write_info, &monster->name, 80);
+    CopyBitsTo(stream, &monster->is_valid, 1);
+    CopyBitsTo(stream, &monster->level, 7);
+    CopyBitsTo(stream, &monster->id, 11);
+    Copy16BitsTo(stream, &monster->joined_at);
+    CopyBitsTo(stream, &monster->level_at_first_evo, 7);
+    CopyBitsTo(stream, &monster->level_at_second_evo, 7);
+    CopyBitsTo(stream, &monster->iq, 10);
+    CopyBitsTo(stream, &monster->max_hp, 10);
+    CopyBitsTo(stream, &monster->offensive_stats[0], 8);
+    CopyBitsTo(stream, &monster->offensive_stats[1], 8);
+    CopyBitsTo(stream, &monster->defensive_stats[0], 8);
+    CopyBitsTo(stream, &monster->defensive_stats[1], 8);
+    CopyBitsTo(stream, &monster->exp, 24);
+    CopyBitsTo(stream, &monster->iq_skill_flags, 69);
+    CopyBitsTo(stream, &monster->tactic, 4);
+    CopyMovesetToStream(stream, (struct ground_move*)&monster->moves);
+    CopyBitsTo(stream, &monster->name, 80);
 }

-void ReadMonsterFromSave(struct WriteMonsterInfoToSave_struct *read_info, struct ground_monster *monster)
+void ReadMonsterFromSave(struct bitstream *stream, struct ground_monster *monster)
 {
    memset(monster, 0, 68);
-    CopyBitsFrom(read_info, &monster->is_valid, 1);
-    CopyBitsFrom(read_info, &monster->level, 7);
-    CopyBitsFrom(read_info, &monster->id, 11);
-    Copy16BitsFrom(read_info, &monster->joined_at);
-    CopyBitsFrom(read_info, &monster->level_at_first_evo, 7);
-    CopyBitsFrom(read_info, &monster->level_at_second_evo, 7);
-    CopyBitsFrom(read_info, &monster->iq, 10);
-    CopyBitsFrom(read_info, &monster->max_hp, 10);
-    CopyBitsFrom(read_info, &monster->offensive_stats[0], 8);
-    CopyBitsFrom(read_info, &monster->offensive_stats[1], 8);
-    CopyBitsFrom(read_info, &monster->defensive_stats[0], 8);
-    CopyBitsFrom(read_info, &monster->defensive_stats[1], 8);
-    CopyBitsFrom(read_info, &monster->exp, 24);
-    CopyBitsFrom(read_info, &monster->iq_skill_flags, 69);
-    CopyBitsFrom(read_info, &monster->tactic, 4);
-    CopyMovesetFrom(read_info, &monster->moves);
-    CopyBitsFrom(read_info, &monster->name, 80);
+    CopyBitsFrom(stream, &monster->is_valid, 1);
+    CopyBitsFrom(stream, &monster->level, 7);
+    CopyBitsFrom(stream, &monster->id, 11);
+    Copy16BitsFrom(stream, &monster->joined_at);
+    CopyBitsFrom(stream, &monster->level_at_first_evo, 7);
+    CopyBitsFrom(stream, &monster->level_at_second_evo, 7);
+    CopyBitsFrom(stream, &monster->iq, 10);
+    CopyBitsFrom(stream, &monster->max_hp, 10);
+    CopyBitsFrom(stream, &monster->offensive_stats[0], 8);
+    CopyBitsFrom(stream, &monster->offensive_stats[1], 8);
+    CopyBitsFrom(stream, &monster->defensive_stats[0], 8);
+    CopyBitsFrom(stream, &monster->defensive_stats[1], 8);
+    CopyBitsFrom(stream, &monster->exp, 24);
+    CopyBitsFrom(stream, &monster->iq_skill_flags, 69);
+    CopyBitsFrom(stream, &monster->tactic, 4);
+    CopyMovesetFromStream(stream, (struct ground_move*)&monster->moves);
+    CopyBitsFrom(stream, &monster->name, 80);
 }
--- a/src/main_0205BD14.c
+++ b/src/main_0205BD14.c
@@ -1,7 +1,8 @@
 #include "main_0205BD14.h"
 #include "common.h"
+#include "save.h"
 #include "main_0200224C.h"
-#include "main_02058FA4.h"
+#include "main_02014A4C.h"
 #include "main_02059A74.h"
 #include "main_0205B690.h"
 #include "main_0205C440.h"
@@ -9,17 +10,15 @@
 extern union unkStruct_020B0A54_union _020B0A54;
 extern u32 _022B57BC;

-extern void InitBitstreamForWrite(void *v0, u32 v1, u32 v2);
-extern void CopyBitsFrom(void *read_info, void *buf_read, s32 nbits);
+extern void InitBitstreamForWrite(struct bitstream *stream, u32 v1, u32 v2);
+extern void CopyBitsFrom(struct bitstream *stream, void *buf_read, s32 nbits);
 extern void* memset(void *s, s32 c, u32 n);
-extern void Copy16BitsFrom(void *read_info, void *buf_read);
-extern void CopyMovesetFrom(struct WriteMonsterInfoToSave_struct *read_info, void *dst);
-extern void BitstreamDebug(struct WriteMonsterInfoToSave_struct *write_info);
+extern void Copy16BitsFrom(struct bitstream *stream, void *buf_read);
+extern void BitstreamDebug(struct bitstream *stream);
 extern void sub_020634F4(void);
-extern void InitBitstreamForRead(struct WriteMonsterInfoToSave_struct *write_info, u32 p1, u32 p2);
-extern void CopyBitsTo(void *write_info, void* buf_write, s32 nbits);
-extern void Copy16BitsTo(void *write_info, void *buf_write);
-extern void CopyMovesetTo(struct WriteMonsterInfoToSave_struct *write_info, void *buffer_write);
+extern void InitBitstreamForRead(struct bitstream *stream, u32 p1, u32 p2);
+extern void CopyBitsTo(struct bitstream *stream, void* buf_write, s32 nbits);
+extern void Copy16BitsTo(struct bitstream *stream, void *buf_write);

 void sub_0205BD14(u32 *dest, s32 index)
 {
@@ -53,120 +52,120 @@ u32 sub_0205BD90(u32 a0)

 u32 sub_0205BD9C(u32 arg0, u32 arg1)
 {
-    struct WriteMonsterInfoToSave_struct temp;
+    struct bitstream stream;

-    InitBitstreamForWrite(&temp, arg0, arg1);
-    CopyBitsFrom(&temp, &_022B57BC, 32);
+    InitBitstreamForWrite(&stream, arg0, arg1);
+    CopyBitsFrom(&stream, &_022B57BC, 32);

    for (s32 i = 0; i < 32; i++)
    {
-        sub_0205C19C(&temp, &_020B0A54.struct0[i]);
+        sub_0205C19C(&stream, &_020B0A54.struct0[i]);
    }

    struct ground_monster *monster = _020B0A54.struct1.unk8.monster;
    memset(monster, 0, 68);

-    CopyBitsFrom(&temp, &monster->is_valid, 4);
-    CopyBitsFrom(&temp, &monster->level, 7);
-    Copy16BitsFrom(&temp, &monster->joined_at);
-    CopyBitsFrom(&temp, &monster->id, 11);
-    sub_02059AE8(&temp, &monster->level_at_first_evo);
-    sub_02059AE8(&temp, &monster->level_at_second_evo);
-    CopyBitsFrom(&temp, &monster->iq, 10);
-    CopyBitsFrom(&temp, &monster->max_hp, 10);
-    CopyBitsFrom(&temp, &monster->offensive_stats[0], 8);
-    CopyBitsFrom(&temp, &monster->offensive_stats[1], 8);
-    CopyBitsFrom(&temp, &monster->defensive_stats[0], 8);
-    CopyBitsFrom(&temp, &monster->defensive_stats[1], 8);
-    CopyBitsFrom(&temp, &monster->exp, 24);
-    CopyBitsFrom(&temp, &monster->iq_skill_flags, 69);
-    CopyBitsFrom(&temp, &monster->tactic, 4);
-    CopyMovesetFrom(&temp, monster->moves);
-    CopyBitsFrom(&temp, monster->name, 80);
+    CopyBitsFrom(&stream, &monster->is_valid, 4);
+    CopyBitsFrom(&stream, &monster->level, 7);
+    Copy16BitsFrom(&stream, &monster->joined_at);
+    CopyBitsFrom(&stream, &monster->id, 11);
+    sub_02059AE8(&stream, &monster->level_at_first_evo);
+    sub_02059AE8(&stream, &monster->level_at_second_evo);
+    CopyBitsFrom(&stream, &monster->iq, 10);
+    CopyBitsFrom(&stream, &monster->max_hp, 10);
+    CopyBitsFrom(&stream, &monster->offensive_stats[0], 8);
+    CopyBitsFrom(&stream, &monster->offensive_stats[1], 8);
+    CopyBitsFrom(&stream, &monster->defensive_stats[0], 8);
+    CopyBitsFrom(&stream, &monster->defensive_stats[1], 8);
+    CopyBitsFrom(&stream, &monster->exp, 24);
+    CopyBitsFrom(&stream, &monster->iq_skill_flags, 69);
+    CopyBitsFrom(&stream, &monster->tactic, 4);
+    CopyMovesetFromStream(&stream, monster->moves);
+    CopyBitsFrom(&stream, monster->name, 80);

    struct unkStruct_020B0A54_unk8_inner *inner = _020B0A54.struct1.unk8.unk8;
    memset(&inner->unk44, 0, 6);
-    CopyBitsFrom(&temp, &inner->unk46, 11);
-    CopyBitsFrom(&temp, &inner->unk48, 11);
+    CopyBitsFrom(&stream, &inner->unk46, 11);
+    CopyBitsFrom(&stream, &inner->unk48, 11);

-    CopyBitsFrom(&temp, (void*) _020B0A54.struct1.unk4, 32);
+    CopyBitsFrom(&stream, (void*) _020B0A54.struct1.unk4, 32);

    for (s32 i = 0; i < 32; i++)
    {
-        CopyBitsFrom(&temp, _020B0A54.fp[1] + 4 + (i * 8), 64);
+        CopyBitsFrom(&stream, _020B0A54.fp[1] + 4 + (i * 8), 64);
    }

-    BitstreamDebug(&temp);
+    BitstreamDebug(&stream);
    Rand16Bit();
    sub_020634F4();

-    return temp.result;
+    return stream.bit_idx;
 }

 u32 sub_0205BFB0(u32 p0, u32 p1)
 {
-    struct WriteMonsterInfoToSave_struct stack_var;
+    struct bitstream stream;

-    InitBitstreamForRead(&stack_var, p0, p1);
-    CopyBitsTo(&stack_var, &_022B57BC, 32);
+    InitBitstreamForRead(&stream, p0, p1);
+    CopyBitsTo(&stream, &_022B57BC, 32);

    for (s32 i = 0; i < 32; i++)
    {
-        sub_0205C440(&stack_var, &_020B0A54.struct0[i]);
+        sub_0205C440(&stream, &_020B0A54.struct0[i]);
    }

    struct ground_monster *monster = _020B0A54.struct1.unk8.monster;
-    CopyBitsTo(&stack_var, &monster->is_valid, 4);
-    CopyBitsTo(&stack_var, &monster->level, 7);
-    Copy16BitsTo(&stack_var, &monster->joined_at);
-    CopyBitsTo(&stack_var, &monster->id, 11);
-    sub_02059AF8(&stack_var, &monster->level_at_first_evo);
-    sub_02059AF8(&stack_var, &monster->level_at_second_evo);
-    CopyBitsTo(&stack_var, &monster->iq, 10);
-    CopyBitsTo(&stack_var, &monster->max_hp, 10);
-    CopyBitsTo(&stack_var, &monster->offensive_stats[0], 8);
-    CopyBitsTo(&stack_var, &monster->offensive_stats[1], 8);
-    CopyBitsTo(&stack_var, &monster->defensive_stats[0], 8);
-    CopyBitsTo(&stack_var, &monster->defensive_stats[1], 8);
-    CopyBitsTo(&stack_var, &monster->exp, 24);
-    CopyBitsTo(&stack_var, &monster->iq_skill_flags, 69);
-    CopyBitsTo(&stack_var, &monster->tactic, 4);
-    CopyMovesetTo(&stack_var, monster->moves);
-    CopyBitsTo(&stack_var, monster->name, 80);
+    CopyBitsTo(&stream, &monster->is_valid, 4);
+    CopyBitsTo(&stream, &monster->level, 7);
+    Copy16BitsTo(&stream, &monster->joined_at);
+    CopyBitsTo(&stream, &monster->id, 11);
+    sub_02059AF8(&stream, &monster->level_at_first_evo);
+    sub_02059AF8(&stream, &monster->level_at_second_evo);
+    CopyBitsTo(&stream, &monster->iq, 10);
+    CopyBitsTo(&stream, &monster->max_hp, 10);
+    CopyBitsTo(&stream, &monster->offensive_stats[0], 8);
+    CopyBitsTo(&stream, &monster->offensive_stats[1], 8);
+    CopyBitsTo(&stream, &monster->defensive_stats[0], 8);
+    CopyBitsTo(&stream, &monster->defensive_stats[1], 8);
+    CopyBitsTo(&stream, &monster->exp, 24);
+    CopyBitsTo(&stream, &monster->iq_skill_flags, 69);
+    CopyBitsTo(&stream, &monster->tactic, 4);
+    CopyMovesetToStream(&stream, monster->moves);
+    CopyBitsTo(&stream, monster->name, 80);

    struct unkStruct_020B0A54_unk8_inner *inner = _020B0A54.struct1.unk8.unk8;
-    CopyBitsTo(&stack_var, &inner->unk46, 11);
-    CopyBitsTo(&stack_var, &inner->unk48, 11);
+    CopyBitsTo(&stream, &inner->unk46, 11);
+    CopyBitsTo(&stream, &inner->unk48, 11);

-    CopyBitsTo(&stack_var, (void*) _020B0A54.struct1.unk4, 32);
+    CopyBitsTo(&stream, (void*) _020B0A54.struct1.unk4, 32);

    for (s32 i = 0; i < 32; i++)
    {
-        CopyBitsTo(&stack_var, _020B0A54.fp[1] + 4 + (i * 8), 64);
+        CopyBitsTo(&stream, _020B0A54.fp[1] + 4 + (i * 8), 64);
    }

-    BitstreamDebug(&stack_var);
+    BitstreamDebug(&stream);

-    return stack_var.result;
+    return stream.bit_idx;
 }

-void sub_0205C19C(struct WriteMonsterInfoToSave_struct *write_info, struct unkStruct_020B0A54 *arg1)
+void sub_0205C19C(struct bitstream *stream, struct unkStruct_020B0A54 *arg1)
 {
-    CopyBitsFrom(write_info, &arg1->unk0, 4);
-    Copy16BitsFrom(write_info, &arg1->unk4);
-    CopyBitsFrom(write_info, &arg1->unk8.monster, 24);
-    CopyBitsFrom(write_info, &arg1->unkC, 64);
-    CopyBitsFrom(write_info, &arg1->unk14, 0x40);
-    CopyBitsFrom(write_info, &arg1->unk1C, 4);
-    CopyBitsFrom(write_info, &arg1->unk1D, 0x50);
-    CopyBitsFrom(write_info, &arg1->unk32, 0x120);
-    CopyBitsFrom(write_info, &arg1->unk56, 0x240);
-    CopyBitsFrom(write_info, &arg1->unkA0, 0xb);
-    CopyBitsFrom(write_info, &arg1->unkA2, 0xb);
-    CopyBitsFrom(write_info, &arg1->unkA4, 0x40);
-    CopyBitsFrom(write_info, &arg1->unkAC, 8);
+    CopyBitsFrom(stream, &arg1->unk0, 4);
+    Copy16BitsFrom(stream, &arg1->unk4);
+    CopyBitsFrom(stream, &arg1->unk8.monster, 24);
+    CopyBitsFrom(stream, &arg1->unkC, 64);
+    CopyBitsFrom(stream, &arg1->unk14, 0x40);
+    CopyBitsFrom(stream, &arg1->unk1C, 4);
+    CopyBitsFrom(stream, &arg1->unk1D, 0x50);
+    CopyBitsFrom(stream, &arg1->unk32, 0x120);
+    CopyBitsFrom(stream, &arg1->unk56, 0x240);
+    CopyBitsFrom(stream, &arg1->unkA0, 0xb);
+    CopyBitsFrom(stream, &arg1->unkA2, 0xb);
+    CopyBitsFrom(stream, &arg1->unkA4, 0x40);
+    CopyBitsFrom(stream, &arg1->unkAC, 8);
    bool8 temp;
-    CopyBitsFrom(write_info, &temp, 1);
+    CopyBitsFrom(stream, &temp, 1);
    arg1->unkAD = temp != FALSE;
-    CopyBitsFrom(write_info, &arg1->unkAE, 2);
+    CopyBitsFrom(stream, &arg1->unkAE, 2);
 }
--- a/src/main_0205C440.c
+++ b/src/main_0205C440.c
@@ -1,26 +1,27 @@
 #include "main_0205C440.h"
+#include "save.h"

 extern u8 _020A3673;
 extern u8 _020A3670;

-extern void CopyBitsTo(void *write_info, void* buf_write, s32 nbits);
-extern void Copy16BitsTo(void *write_info, void *buf_write);
+extern void CopyBitsTo(struct bitstream *stream, void* buf_write, s32 nbits);
+extern void Copy16BitsTo(struct bitstream *stream, void *buf_write);

-void sub_0205C440(struct WriteMonsterInfoToSave_struct *write_info, struct unkStruct_020B0A54 *p1)
+void sub_0205C440(struct bitstream *stream, struct unkStruct_020B0A54 *p1)
 {
-    CopyBitsTo(write_info, &p1->unk0, 4);
-    Copy16BitsTo(write_info, &p1->unk4);
-    CopyBitsTo(write_info, &p1->unk8.monster, 24);
-    CopyBitsTo(write_info, &p1->unkC, 64);
-    CopyBitsTo(write_info, &p1->unk14, 0x40);
-    CopyBitsTo(write_info, &p1->unk1C, 4);
-    CopyBitsTo(write_info, &p1->unk1D, 0x50);
-    CopyBitsTo(write_info, &p1->unk32, 0x120);
-    CopyBitsTo(write_info, &p1->unk56, 0x240);
-    CopyBitsTo(write_info, &p1->unkA0, 0xb);
-    CopyBitsTo(write_info, &p1->unkA2, 0xb);
-    CopyBitsTo(write_info, &p1->unkA4, 0x40);
-    CopyBitsTo(write_info, &p1->unkAC, 8);
-    CopyBitsTo(write_info, p1->unkAD == TRUE ? &_020A3673 : &_020A3670, 1);
-    CopyBitsTo(write_info, &p1->unkAE, 2);
+    CopyBitsTo(stream, &p1->unk0, 4);
+    Copy16BitsTo(stream, &p1->unk4);
+    CopyBitsTo(stream, &p1->unk8.monster, 24);
+    CopyBitsTo(stream, &p1->unkC, 64);
+    CopyBitsTo(stream, &p1->unk14, 0x40);
+    CopyBitsTo(stream, &p1->unk1C, 4);
+    CopyBitsTo(stream, &p1->unk1D, 0x50);
+    CopyBitsTo(stream, &p1->unk32, 0x120);
+    CopyBitsTo(stream, &p1->unk56, 0x240);
+    CopyBitsTo(stream, &p1->unkA0, 0xb);
+    CopyBitsTo(stream, &p1->unkA2, 0xb);
+    CopyBitsTo(stream, &p1->unkA4, 0x40);
+    CopyBitsTo(stream, &p1->unkAC, 8);
+    CopyBitsTo(stream, p1->unkAD == TRUE ? &_020A3673 : &_020A3670, 1);
+    CopyBitsTo(stream, &p1->unkAE, 2);
 }