From: Toni Wilen <twilen@winuae.net>
Date: Sun, 9 Jul 2023 17:20:26 +0000 (+0300)
Subject: Randomize emulator startup state by default, configurable random seed.
X-Git-Tag: 5.1.0~165
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=62bace6406c30995b14948085efa9f02c8036330;p=francis%2Fwinuae.git

Randomize emulator startup state by default, configurable random seed.
---

diff --git a/cfgfile.cpp b/cfgfile.cpp
index 887a7fa4..35df82f5 100644
--- a/cfgfile.cpp
+++ b/cfgfile.cpp
@@ -2755,6 +2755,9 @@ void cfgfile_save_options (struct zfile *f, struct uae_prefs *p, int type)
 	cfgfile_dwrite_strarr(f, _T("agnusmodel"), agnusmodel, p->cs_agnusmodel);
 	cfgfile_dwrite_strarr(f, _T("agnussize"), agnussize, p->cs_agnussize);
 	cfgfile_dwrite_strarr(f, _T("denisemodel"), denisemodel, p->cs_denisemodel);
+	if (p->seed) {
+		cfgfile_write(f, _T("rndseed"), _T("%d"), p->seed);
+	}
 
 	if (is_board_enabled(p, ROMTYPE_CD32CART, 0)) {
 		cfgfile_dwrite_bool(f, _T("cd32fmv"), true);
@@ -5971,7 +5974,8 @@ static int cfgfile_parse_hardware (struct uae_prefs *p, const TCHAR *option, TCH
 		|| cfgfile_intval(option, value, _T("genlock_mix"), &p->genlock_mix, 1)
 		|| cfgfile_intval(option, value, _T("keyboard_handshake"), &p->cs_kbhandshake, 1)
 		|| cfgfile_intval(option, value, _T("eclockphase"), &p->cs_eclockphase, 1)
-		|| cfgfile_intval(option, value, _T("chipset_rtc_adjust"), &p->cs_rtc_adjust, 1))
+		|| cfgfile_intval(option, value, _T("chipset_rtc_adjust"), &p->cs_rtc_adjust, 1)
+		|| cfgfile_intval(option, value, _T("rndseed"), &p->seed, 1))
 		return 1;
 
 	if (cfgfile_strval(option, value, _T("comp_trustbyte"), &p->comptrustbyte, compmode, 0)
diff --git a/include/options.h b/include/options.h
index 5c13517b..b83c9028 100644
--- a/include/options.h
+++ b/include/options.h
@@ -729,6 +729,7 @@ struct uae_prefs {
 	int cs_denisemodel;
 	bool cs_memorypatternfill;
 	bool cs_ipldelay;
+	uae_u32 seed;
 
 	struct boardromconfig expansionboard[MAX_EXPANSION_BOARDS];
 
diff --git a/include/uae.h b/include/uae.h
index 94ef91bb..600b7bc9 100644
--- a/include/uae.h
+++ b/include/uae.h
@@ -86,9 +86,9 @@ extern void fetch_inputfilepath(TCHAR *out, int size);
 extern void fetch_datapath(TCHAR *out, int size);
 extern void fetch_rompath(TCHAR *out, int size);
 extern void fetch_videopath(TCHAR *out, int size);
-extern uae_u32 uaerand (void);
-extern uae_u32 uaesrand (uae_u32 seed);
-extern uae_u32 uaerandgetseed (void);
+extern uae_u32 uaerand(void);
+extern uae_u32 uaesetrandseed(uae_u32 seed);
+extern uae_u32 uaerandgetseed(void);
 
 /* the following prototypes should probably be moved somewhere else */
 
diff --git a/inputrecord.cpp b/inputrecord.cpp
index 92deb2c2..117fc79b 100644
--- a/inputrecord.cpp
+++ b/inputrecord.cpp
@@ -393,32 +393,32 @@ int inprec_open (const TCHAR *fname, const TCHAR *statefilename)
 	header_end2 = 0;
 	if (input_play) {
 		uae_u32 id;
-		zfile_fseek (inprec_zf, 0, SEEK_END);
+		zfile_fseek(inprec_zf, 0, SEEK_END);
 		inprec_size = zfile_ftell32(inprec_zf);
-		zfile_fseek (inprec_zf, 0, SEEK_SET);
+		zfile_fseek(inprec_zf, 0, SEEK_SET);
 		inprec_buffer = inprec_p = xmalloc (uae_u8, inprec_size);
-		zfile_fread (inprec_buffer, inprec_size, 1, inprec_zf);
+		zfile_fread(inprec_buffer, inprec_size, 1, inprec_zf);
 		inprec_plastptr = inprec_buffer;
 		id = inprec_pu32();
 		if (id != 'UAE\0') {
-			inprec_close (true);
+			inprec_close(true);
 			return 0;
 		}
-		int v = inprec_pu8 ();
+		int v = inprec_pu8();
 		if (v != 3) {
-			inprec_close (true);
+			inprec_close(true);
 			return 0;
 		}
-		inprec_pu8 ();
-		inprec_pu8 ();
-		inprec_pu8 ();
+		inprec_pu8();
+		inprec_pu8();
+		inprec_pu8();
 		seed = inprec_pu32();
-		seed = uaesrand (seed);
-		vsync_counter = inprec_pu32 ();
-		hsync_counter = inprec_pu32 ();
-		i = inprec_pu32 ();
+		seed = uaesetrandseed(seed);
+		vsync_counter = inprec_pu32();
+		hsync_counter = inprec_pu32();
+		i = inprec_pu32();
 		while (i-- > 0)
-			inprec_pu8 ();
+			inprec_pu8();
 		header_end = addrdiff(inprec_plastptr, inprec_buffer);
 		inprec_pstr (savestate_fname);
 		if (savestate_fname[0]) {
@@ -466,17 +466,17 @@ int inprec_open (const TCHAR *fname, const TCHAR *statefilename)
 		header_end2 = addrdiff(inprec_plastptr,  inprec_buffer);
 		findlast ();
 	} else if (input_record) {
-		seed = uaesrand (seed);
-		inprec_buffer = inprec_p = xmalloc (uae_u8, inprec_size);
-		inprec_ru32 ('UAE\0');
-		inprec_ru8 (3);
-		inprec_ru8 (UAEMAJOR);
-		inprec_ru8 (UAEMINOR);
-		inprec_ru8 (UAESUBREV);
-		inprec_ru32 (seed);
-		inprec_ru32 (vsync_counter);
-		inprec_ru32 (hsync_counter);
-		inprec_ru32 (0); // extra header size
+		seed = uaesetrandseed(seed);
+		inprec_buffer = inprec_p = xmalloc(uae_u8, inprec_size);
+		inprec_ru32('UAE\0');
+		inprec_ru8(3);
+		inprec_ru8(UAEMAJOR);
+		inprec_ru8(UAEMINOR);
+		inprec_ru8(UAESUBREV);
+		inprec_ru32(seed);
+		inprec_ru32(vsync_counter);
+		inprec_ru32(hsync_counter);
+		inprec_ru32(0); // extra header size
 		flush ();
 		header_end2 = header_end = zfile_ftell32(inprec_zf);
 	} else {
@@ -494,7 +494,7 @@ int inprec_open (const TCHAR *fname, const TCHAR *statefilename)
 
 void inprec_startup (void)
 {
-	uaesrand (seed);
+	uaesetrandseed(seed);
 }
 
 bool inprec_prepare_record (const TCHAR *statefilename)
diff --git a/main.cpp b/main.cpp
index 2860d494..5e33db41 100644
--- a/main.cpp
+++ b/main.cpp
@@ -71,9 +71,8 @@ TCHAR warning_buffer[256];
 TCHAR optionsfile[256];
 
 static uae_u32 randseed;
-static int oldhcounter;
 
-static uae_u32 xorshiftstate = 1;
+static uae_u32 xorshiftstate;
 static uae_u32 xorshift32(void)
 {
 	uae_u32 x = xorshiftstate;
@@ -84,23 +83,35 @@ static uae_u32 xorshift32(void)
 	return xorshiftstate;
 }
 
-uae_u32 uaesrand(uae_u32 seed)
-{
-	oldhcounter = -1;
-	randseed = seed;
-	return randseed;
-}
 uae_u32 uaerand(void)
 {
-	if (oldhcounter != hsync_counter) {
-		xorshiftstate = (hsync_counter ^ randseed) | 1;
-		oldhcounter = hsync_counter;
+	if (xorshiftstate == 0) {
+		xorshiftstate = randseed;
+		if (!xorshiftstate) {
+			randseed = 1;
+			xorshiftstate = 1;
+		}
 	}
 	uae_u32 r = xorshift32();
 	return r;
 }
+
 uae_u32 uaerandgetseed(void)
 {
+	if (!randseed) {
+		randseed = 1;
+		xorshiftstate = 1;
+	}
+	return randseed;
+}
+
+uae_u32 uaesetrandseed(uae_u32 seed)
+{
+	if (!seed) {
+		seed = 1;
+	}
+	randseed = seed;
+	xorshiftstate = seed;
 	return randseed;
 }
 
@@ -1183,6 +1194,12 @@ static int real_main2 (int argc, TCHAR **argv)
 #ifdef RETROPLATFORM
 	rp_fixup_options (&currprefs);
 #endif
+	if (currprefs.seed == 0) {
+		uae_u32 t = getlocaltime();
+		uaesetrandseed(t);
+	} else {
+		uaesetrandseed(currprefs.seed);
+	}
 	copy_prefs(&currprefs, &changed_prefs);
 	target_run ();
 	/* force sound settings change */
diff --git a/newcpu.cpp b/newcpu.cpp
index 0a26cedf..ca4faccf 100644
--- a/newcpu.cpp
+++ b/newcpu.cpp
@@ -6626,10 +6626,24 @@ void m68k_go (int may_quit)
 		}
 		cpu_hardreset = false;
 		cpu_keyboardreset = false;
-		hardboot = 0;
 		event_wait = true;
 		unset_special(SPCFLAG_MODE_CHANGE);
 
+		if (!restored && hardboot) {
+			uae_u32 s = uaerandgetseed();
+			uaesetrandseed(s);
+			write_log("rndseed = %08x (%u)\n", s, s);
+			// add random delay before CPU starts
+			int t = uaerand() & 0x7fff;
+			while (t > 255) {
+				x_do_cycles(255 * CYCLE_UNIT);
+				t -= 255;
+			}
+			x_do_cycles(t * CYCLE_UNIT);
+		}
+
+		hardboot = 0;
+
 #ifdef SAVESTATE
 		if (restored) {
 			restored = 0;