[Decompilation] [th01] mdrv2_resident

I thought this would be a good target for my first attempt at
decompilation. Should have known something was up, because it's the only
undecompiled proc in the translation unit.

Oh well, SCOPY stands for "structure copy" anyway. /s

th01/mdrv2.c

@@ -28,6 +28,26 @@ typedef enum {
 } mdrv2_func_t;
 
 extern char mdrv2_have_board;
+struct hack { char x[12]; }; // XXX
+extern const struct hack mdrv2_magic;
+
+int far mdrv2_resident(void)
+{
+	char s1[sizeof(mdrv2_magic)];
+	const struct hack s2 = mdrv2_magic;
+	char far *magicp = (char far *)(
+		((long)peek(0, MDRV2 * 4 + 2) << 16) + 0x102
+	);
+	int i;
+
+	for(i = 0; i < sizeof(s1); i++) {
+		s1[i] = magicp[i];
+	}
+	if(strcmp(s1, s2.x) != 0) {
+		return 0;
+	}
+	return 1;
+}
 
 static void near pascal mdrv2_load(const char *fn, char func)
 {

th01/mdrv2[data].asm

@@ -0,0 +1,5 @@
+public _mdrv2_have_board
+_mdrv2_have_board	db 0
+		db 0
+public _mdrv2_magic
+_mdrv2_magic	db 'Mdrv2System',0

th01_fuuin.asm

@@ -316,7 +316,7 @@ _envp		= dword	ptr  0Ch
 
 		push	bp
 		mov	bp, sp
-		call	sub_EF80
+		call	_mdrv2_resident
 		or	ax, ax
 		jnz	short loc_A105
 		pop	bp
@@ -9909,74 +9909,7 @@ fuuin_12_TEXT	ends
 
 ; Segment type:	Pure code
 fuuin_13_TEXT	segment	byte public 'CODE' use16
-		assume cs:fuuin_13_TEXT
+	extern _mdrv2_resident:proc
-		assume es:nothing, ss:nothing, ds:_DATA, fs:nothing, gs:nothing
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_EF80	proc far
-
-s2		= byte ptr -1Ch
-s1		= byte ptr -10h
-var_4		= dword	ptr -4
-
-		enter	1Ch, 0
-		push	si
-		lea	ax, [bp+s2]
-		push	ss
-		push	ax
-		push	ds
-		push	offset aMdrv2system ; "Mdrv2System"
-		mov	cx, 0Ch
-		call	SCOPY@
-		xor	ax, ax
-		mov	es, ax
-		movsx	eax, word ptr es:[03CAh]
-		shl	eax, 10h
-		add	eax, 102h
-		shld	edx, eax, 10h
-		mov	word ptr [bp+var_4+2], dx
-		mov	word ptr [bp+var_4], ax
-		xor	si, si
-		jmp	short loc_EFC6
-; ---------------------------------------------------------------------------
-
-loc_EFBA:
-		les	bx, [bp+var_4]
-		assume es:nothing
-		add	bx, si
-		mov	al, es:[bx]
-		mov	[bp+si+s1], al
-		inc	si
-
-loc_EFC6:
-		cmp	si, 0Ch
-		jl	short loc_EFBA
-		push	ss
-		lea	ax, [bp+s2]
-		push	ax		; s2
-		push	ss
-		lea	ax, [bp+s1]
-		push	ax		; s1
-		call	_strcmp
-		add	sp, 8
-		or	ax, ax
-		jz	short loc_EFE5
-		xor	ax, ax
-		jmp	short loc_EFE8
-; ---------------------------------------------------------------------------
-
-loc_EFE5:
-		mov	ax, 1
-
-loc_EFE8:
-		pop	si
-		leave
-		retf
-sub_EF80	endp
-
 	extern _mdrv2_bgm_load:proc
 	extern _mdrv2_se_load:proc
 	extern _mdrv2_bgm_play:proc
@@ -10338,10 +10271,7 @@ word_134FA	dw 1
 		db    0
 word_13507	dw 64h
 byte_13509	db 0
-public _mdrv2_have_board
+include th01/mdrv2[data].asm
-_mdrv2_have_board	db 0
-		db 0
-aMdrv2system	db 'Mdrv2System',0
 include libs/master.lib/version[data].asm
 include libs/master.lib/grp[data].asm
 include libs/master.lib/pal[data].asm

th01_op.asm

@@ -7578,75 +7578,7 @@ op_10_TEXT	ends
 
 ; Segment type:	Pure code
 op_11_TEXT	segment	byte public 'CODE' use16
-		assume cs:op_11_TEXT
+	extern _mdrv2_resident:proc
-		;org 5
-		assume es:nothing, ss:nothing, ds:_DATA, fs:nothing, gs:nothing
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-_mdrv2_resident	proc far
-
-s2		= byte ptr -1Ch
-s1		= byte ptr -10h
-var_4		= dword	ptr -4
-
-		enter	1Ch, 0
-		push	si
-		lea	ax, [bp+s2]
-		push	ss
-		push	ax
-		push	ds
-		push	offset aMdrv2system ; "Mdrv2System"
-		mov	cx, 0Ch
-		call	SCOPY@
-		xor	ax, ax
-		mov	es, ax
-		movsx	eax, word ptr es:[03CAh]
-		shl	eax, 10h
-		add	eax, 102h
-		shld	edx, eax, 10h
-		mov	word ptr [bp+var_4+2], dx
-		mov	word ptr [bp+var_4], ax
-		xor	si, si
-		jmp	short loc_E42B
-; ---------------------------------------------------------------------------
-
-loc_E41F:
-		les	bx, [bp+var_4]
-		assume es:nothing
-		add	bx, si
-		mov	al, es:[bx]
-		mov	[bp+si+s1], al
-		inc	si
-
-loc_E42B:
-		cmp	si, 0Ch
-		jl	short loc_E41F
-		push	ss
-		lea	ax, [bp+s2]
-		push	ax		; s2
-		push	ss
-		lea	ax, [bp+s1]
-		push	ax		; s1
-		call	_strcmp
-		add	sp, 8
-		or	ax, ax
-		jz	short loc_E44A
-		xor	ax, ax
-		jmp	short loc_E44D
-; ---------------------------------------------------------------------------
-
-loc_E44A:
-		mov	ax, 1
-
-loc_E44D:
-		pop	si
-		leave
-		retf
-_mdrv2_resident	endp
-
 	extern _mdrv2_bgm_load:proc
 	extern _mdrv2_bgm_play:proc
 	extern _mdrv2_bgm_stop:proc
@@ -7654,7 +7586,6 @@ _mdrv2_resident	endp
 	extern _mdrv2_check_board:proc
 op_11_TEXT	ends
 
-; ---------------------------------------------------------------------------
 ; ===========================================================================
 
 op_12_TEXT	segment	byte public 'CODE' use16
@@ -8025,10 +7956,7 @@ include libs/master.lib/clip[data].asm
 include libs/master.lib/rand[data].asm
 public _res_id
 _res_id	db 'ReiidenConfig',0
-public _mdrv2_have_board
+include th01/mdrv2[data].asm
-_mdrv2_have_board	db 0
-		db 0
-aMdrv2system	db 'Mdrv2System',0
 	.data?
 
 ; TODO: Missing clip[bss].asm (16 bytes) somewhere in there...

th01_reiiden.asm

@@ -4012,7 +4012,7 @@ _envp		= dword	ptr  0Ch
 		mov	[bp+var_2], 0
 		xor	si, si
 		mov	[bp+var_4], 0
-		call	sub_12455
+		call	_mdrv2_resident
 		or	ax, ax
 		jnz	short loc_D54F
 		jmp	short loc_D579
@@ -12723,75 +12723,7 @@ main_15_TEXT	ends
 
 ; Segment type:	Pure code
 main_16_TEXT	segment	byte public 'CODE' use16
-		assume cs:main_16_TEXT
+	extern _mdrv2_resident:proc
-		;org 5
-		assume es:nothing, ss:nothing, ds:_DATA, fs:nothing, gs:nothing
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_12455	proc far
-
-_s2		= byte ptr -1Ch
-s1		= byte ptr -10h
-var_4		= dword	ptr -4
-
-		enter	1Ch, 0
-		push	si
-		lea	ax, [bp+_s2]
-		push	ss
-		push	ax
-		push	ds
-		push	offset aMdrv2system ; "Mdrv2System"
-		mov	cx, 0Ch
-		call	SCOPY@
-		xor	ax, ax
-		mov	es, ax
-		movsx	eax, word ptr es:[03CAh]
-		shl	eax, 10h
-		add	eax, 102h
-		shld	edx, eax, 10h
-		mov	word ptr [bp+var_4+2], dx
-		mov	word ptr [bp+var_4], ax
-		xor	si, si
-		jmp	short loc_1249B
-; ---------------------------------------------------------------------------
-
-loc_1248F:
-		les	bx, [bp+var_4]
-		assume es:nothing
-		add	bx, si
-		mov	al, es:[bx]
-		mov	[bp+si+s1], al
-		inc	si
-
-loc_1249B:
-		cmp	si, 0Ch
-		jl	short loc_1248F
-		push	ss
-		lea	ax, [bp+_s2]
-		push	ax		; s2
-		push	ss
-		lea	ax, [bp+s1]
-		push	ax		; s1
-		call	_strcmp
-		add	sp, 8
-		or	ax, ax
-		jz	short loc_124BA
-		xor	ax, ax
-		jmp	short loc_124BD
-; ---------------------------------------------------------------------------
-
-loc_124BA:
-		mov	ax, 1
-
-loc_124BD:
-		pop	si
-		leave
-		retf
-sub_12455	endp
-
 	extern _mdrv2_bgm_load:proc
 	extern _mdrv2_se_load:proc
 	extern _mdrv2_bgm_play:proc
@@ -29839,10 +29771,7 @@ unk_355EC	db    0
 		db 0FCh
 		db    1
 		db 0FEh
-public _mdrv2_have_board
+include th01/mdrv2[data].asm
-_mdrv2_have_board	db 0
-		db 0
-aMdrv2system	db 'Mdrv2System',0
 aVqvnvtvmvcb@vp	db 'ＲＯＵＮＤ　１　ＣＬＥＡＲ',0
 aVbvpvovzvtvbvf	db 'Ｃｏｎｇｒａｔｕｌａｔｉｏｎ！！',0
 aVrvevmvevgvfb@	db 'Ｓｅｌｅｃｔ　ｎｅｘｔ　Ｒｏｕｎｄ',0