X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=common%2Femu.c;h=507437af4fe0b6eb7b0ce6b6e0411bf75f401270;hb=35cbf2ec89d87204288d4d40ad46bf77361e5cfe;hp=118dc38314b923114606186f4668d9ae69b766ee;hpb=f71361b521c9c64351ea99ed97627a606c642008;p=libpicofe.git

diff --git a/common/emu.c b/common/emu.c
index 118dc38..507437a 100644
--- a/common/emu.c
+++ b/common/emu.c
@@ -1,4 +1,4 @@
-// (c) Copyright 2006-2007 notaz, All rights reserved.
+// (c) Copyright 2006-2009 notaz, All rights reserved.
 // Free for non-commercial use.
 
 // For commercial use, separate licencing terms must be obtained.
@@ -22,7 +22,6 @@
 #include <pico/pico_int.h>
 #include <pico/patch.h>
 #include <pico/cd/cue.h>
-#include <zlib/zlib.h>
 
 
 #define STATUS_MSG_TIMEOUT 2000
@@ -175,8 +174,7 @@ static int emu_isBios(const char *name)
 
 static unsigned char id_header[0x100];
 
-/* checks if fname points to valid MegaCD image
- * if so, checks for suitable BIOS */
+/* checks if fname points to valid MegaCD image */
 static int emu_cd_check(int *pregion, const char *fname_in)
 {
 	const char *fname = fname_in;
@@ -244,6 +242,96 @@ static int emu_cd_check(int *pregion, const char *fname_in)
 	return type;
 }
 
+static int detect_media(const char *fname)
+{
+	static const short sms_offsets[] = { 0x7ff0, 0x3ff0, 0x1ff0 };
+	static const char *sms_exts[] = { "sms", "gg", "sg" };
+	static const char *md_exts[] = { "gen", "bin", "smd" };
+	char buff0[32], buff[32];
+	unsigned short *d16;
+	pm_file *pmf;
+	char ext[5];
+	int i;
+
+	get_ext(fname, ext);
+
+	// detect wrong extensions
+	if (!strcmp(ext, ".srm") || !strcmp(ext, "s.gz") || !strcmp(ext, ".mds")) // s.gz ~ .mds.gz
+		return PM_BAD;
+
+	/* don't believe in extensions, except .cue */
+	if (strcasecmp(ext, ".cue") == 0)
+		return PM_CD;
+
+	pmf = pm_open(fname);
+	if (pmf == NULL)
+		return PM_BAD;
+
+	if (pm_read(buff0, 32, pmf) != 32) {
+		pm_close(pmf);
+		return PM_BAD;
+	}
+
+	if (strncasecmp("SEGADISCSYSTEM", buff0 + 0x00, 14) == 0 ||
+	    strncasecmp("SEGADISCSYSTEM", buff0 + 0x10, 14) == 0) {
+		pm_close(pmf);
+		return PM_CD;
+	}
+
+	/* check for SMD evil */
+	if (pmf->size >= 0x4200 && (pmf->size & 0x3fff) == 0x200) {
+		if (pm_seek(pmf, sms_offsets[0] + 0x200, SEEK_SET) == sms_offsets[0] + 0x200 &&
+		    pm_read(buff, 16, pmf) == 16 &&
+		    strncmp("TMR SEGA", buff, 8) == 0)
+			goto looks_like_sms;
+
+		/* could parse further but don't bother */
+		goto extension_check;
+	}
+
+	/* MD header? Act as TMSS BIOS here */
+	if (pm_seek(pmf, 0x100, SEEK_SET) == 0x100 && pm_read(buff, 16, pmf) == 16) {
+		if (strncmp(buff, "SEGA", 4) == 0 || strncmp(buff, " SEG", 4) == 0)
+			goto looks_like_md;
+	}
+
+	for (i = 0; i < array_size(sms_offsets); i++) {
+		if (pm_seek(pmf, sms_offsets[i], SEEK_SET) != sms_offsets[i])
+			continue;
+
+		if (pm_read(buff, 16, pmf) != 16)
+			continue;
+
+		if (strncmp("TMR SEGA", buff, 8) == 0)
+			goto looks_like_sms;
+	}
+
+extension_check:
+	/* probably some headerless thing. Maybe check the extension after all. */
+	for (i = 0; i < array_size(md_exts); i++)
+		if (strcasecmp(pmf->ext, md_exts[i]) == 0)
+			goto looks_like_md;
+
+	for (i = 0; i < array_size(sms_exts); i++)
+		if (strcasecmp(pmf->ext, sms_exts[i]) == 0)
+			goto looks_like_sms;
+
+	/* If everything else fails, make a guess on the reset vector */
+	d16 = (unsigned short *)(buff0 + 4);
+	if ((((d16[0] << 16) | d16[1]) & 0xffffff) >= pmf->size) {
+		lprintf("bad MD reset vector, assuming SMS\n");
+		goto looks_like_sms;
+	}
+
+looks_like_md:
+	pm_close(pmf);
+	return PM_MD_CART;
+
+looks_like_sms:
+	pm_close(pmf);
+	return PM_MARK3;
+}
+
 static int extract_text(char *dest, const unsigned char *src, int len, int swab)
 {
 	char *p = dest;
@@ -321,7 +409,34 @@ static void shutdown_MCD(void)
 	PicoAHW &= ~PAHW_MCD;
 }
 
+static void system_announce(void)
+{
+	const char *sys_name, *tv_standard;
+	int fps;
+
+	if (PicoAHW & PAHW_SMS) {
+		sys_name = "Master System";
+	} else if (PicoAHW & PAHW_PICO) {
+		sys_name = "Pico";
+	} else if (PicoAHW & PAHW_MCD) {
+		sys_name = "Mega CD";
+		if ((Pico.m.hardware & 0xc0) == 0x80)
+			sys_name = "Sega CD";
+	} else if (PicoAHW & PAHW_32X) {
+		sys_name = "32X";
+	} else {
+		sys_name = "MegaDrive";
+		if ((Pico.m.hardware & 0xc0) == 0x80)
+			sys_name = "Genesis";
+	}
+	tv_standard = Pico.m.pal ? "PAL" : "NTSC";
+	fps = Pico.m.pal ? 50 : 60;
+
+	emu_status_msg("%s %s / %dFPS", tv_standard, sys_name, fps);
+}
+
 // note: this function might mangle rom_fname
+// XXX: portions of this code should move to pico/
 int emu_reload_rom(char *rom_fname)
 {
 	unsigned int rom_size = 0;
@@ -329,20 +444,14 @@ int emu_reload_rom(char *rom_fname)
 	unsigned char *rom_data = NULL;
 	char ext[5];
 	pm_file *rom = NULL;
-	int ret, cd_state, cd_region, cfg_loaded = 0;
+	int cd_state = CIT_NOT_CD;
+	int ret, media_type, cd_region;
+	int cfg_loaded = 0, bad_rom = 0;
 
 	lprintf("emu_ReloadRom(%s)\n", rom_fname);
 
 	get_ext(rom_fname, ext);
 
-	// detect wrong extensions
-	if (!strcmp(ext, ".srm") || !strcmp(ext, "s.gz") || !strcmp(ext, ".mds")) { // s.gz ~ .mds.gz
-		me_update_msg("Not a ROM/CD selected.");
-		return 0;
-	}
-
-	PicoPatchUnload();
-
 	// check for movie file
 	if (movie_data) {
 		free(movie_data);
@@ -397,90 +506,107 @@ int emu_reload_rom(char *rom_fname)
 		get_ext(rom_fname, ext);
 	}
 
+	media_type = detect_media(rom_fname);
+	if (media_type == PM_BAD) {
+		me_update_msg("Not a ROM/CD img selected.");
+		return 0;
+	}
+
 	shutdown_MCD();
+	PicoPatchUnload();
+	PicoCartUnload();
+	rom_loaded = 0;
+
+	PicoAHW = 0;
 
-	// check for MegaCD image
-	cd_state = emu_cd_check(&cd_region, rom_fname);
-	if (cd_state >= 0 && cd_state != CIT_NOT_CD)
+	if (media_type == PM_CD)
 	{
-		PicoAHW |= PAHW_MCD;
-		// valid CD image, check for BIOS..
+		// check for MegaCD image
+		cd_state = emu_cd_check(&cd_region, rom_fname);
+		if (cd_state >= 0 && cd_state != CIT_NOT_CD)
+		{
+			// valid CD image, check for BIOS..
+
+			// we need to have config loaded at this point
+			ret = emu_read_config(1, 0);
+			if (!ret) emu_read_config(0, 0);
+			cfg_loaded = 1;
 
-		// we need to have config loaded at this point
-		ret = emu_read_config(1, 1);
-		if (!ret) emu_read_config(0, 1);
-		cfg_loaded = 1;
+			if (PicoRegionOverride) {
+				cd_region = PicoRegionOverride;
+				lprintf("override region to %s\n", cd_region != 4 ?
+					(cd_region == 8 ? "EU" : "JAP") : "USA");
+			}
+			if (!find_bios(cd_region, &used_rom_name))
+				return 0;
 
-		if (PicoRegionOverride) {
-			cd_region = PicoRegionOverride;
-			lprintf("overrided region to %s\n", cd_region != 4 ? (cd_region == 8 ? "EU" : "JAP") : "USA");
+			get_ext(used_rom_name, ext);
+			PicoAHW |= PAHW_MCD;
 		}
-		if (!find_bios(cd_region, &used_rom_name)) {
-			PicoAHW &= ~PAHW_MCD;
+		else {
+			me_update_msg("Invalid CD image");
 			return 0;
 		}
-
-		get_ext(used_rom_name, ext);
 	}
-	else
-	{
-		if (PicoAHW & PAHW_MCD) Stop_CD();
-		PicoAHW &= ~PAHW_MCD;
+	else if (media_type == PM_MARK3) {
+		lprintf("detected SMS ROM\n");
+		PicoAHW = PAHW_SMS;
 	}
 
 	rom = pm_open(used_rom_name);
-	if (!rom) {
-		me_update_msg("Failed to open ROM/CD image");
-		goto fail;
-	}
-
-	if (cd_state < 0) {
-		me_update_msg("Invalid CD image");
-		goto fail;
+	if (rom == NULL) {
+		me_update_msg("Failed to open ROM");
+		return 0;
 	}
 
 	menu_romload_prepare(used_rom_name); // also CD load
 
-	PicoCartUnload();
-	rom_loaded = 0;
-
-	if ( (ret = PicoCartLoad(rom, &rom_data, &rom_size)) ) {
+	ret = PicoCartLoad(rom, &rom_data, &rom_size, (PicoAHW & PAHW_SMS) ? 1 : 0);
+	pm_close(rom);
+	if (ret != 0) {
 		if      (ret == 2) me_update_msg("Out of memory");
 		else if (ret == 3) me_update_msg("Read failed");
 		else               me_update_msg("PicoCartLoad() failed.");
-		goto fail2;
+		goto fail;
 	}
-	pm_close(rom);
-	rom = NULL;
 
-	// detect wrong files (Pico crashes on very small files), also see if ROM EP is good
-	if (rom_size <= 0x200 || strncmp((char *)rom_data, "Pico", 4) == 0 ||
-	  ((*(unsigned char *)(rom_data+4)<<16)|(*(unsigned short *)(rom_data+6))) >= (int)rom_size) {
-		if (rom_data) free(rom_data);
-		me_update_msg("Not a ROM selected.");
-		goto fail2;
+	// detect wrong files
+	if (strncmp((char *)rom_data, "Pico", 4) == 0)
+		bad_rom = 1;
+	else if (!(PicoAHW & PAHW_SMS)) {
+		unsigned short *d = (unsigned short *)(rom_data + 4);
+		if ((((d[0] << 16) | d[1]) & 0xffffff) >= (int)rom_size) {
+			lprintf("bad reset vector\n");
+			bad_rom = 1;
+		}
+	}
+
+	if (bad_rom) {
+		me_update_msg("Bad ROM detected.");
+		goto fail;
 	}
 
 	// load config for this ROM (do this before insert to get correct region)
 	if (!(PicoAHW & PAHW_MCD))
 		memcpy(id_header, rom_data + 0x100, sizeof(id_header));
 	if (!cfg_loaded) {
-		ret = emu_read_config(1, 1);
-		if (!ret) emu_read_config(0, 1);
+		ret = emu_read_config(1, 0);
+		if (!ret) emu_read_config(0, 0);
 	}
 
-	lprintf("PicoCartInsert(%p, %d);\n", rom_data, rom_size);
 	if (PicoCartInsert(rom_data, rom_size)) {
 		me_update_msg("Failed to load ROM.");
-		goto fail2;
+		goto fail;
 	}
 
 	// insert CD if it was detected
 	if (cd_state != CIT_NOT_CD) {
 		ret = Insert_CD(rom_fname, cd_state);
 		if (ret != 0) {
+			PicoCartUnload();
+			rom_data = NULL; // freed by unload
 			me_update_msg("Insert_CD() failed, invalid CD image?");
-			goto fail2;
+			goto fail;
 		}
 	}
 
@@ -512,23 +638,24 @@ int emu_reload_rom(char *rom_fname)
 	}
 	else
 	{
+		system_announce();
 		PicoOpt &= ~POPT_DIS_VDP_FIFO;
-		emu_status_msg(Pico.m.pal ? "PAL SYSTEM / 50 FPS" : "NTSC SYSTEM / 60 FPS");
 	}
 
+	strncpy(rom_fname_loaded, rom_fname, sizeof(rom_fname_loaded)-1);
+	rom_fname_loaded[sizeof(rom_fname_loaded)-1] = 0;
+	rom_loaded = 1;
+
 	// load SRAM for this ROM
 	if (currentConfig.EmuOpt & EOPT_EN_SRAM)
 		emu_save_load_game(1, 1);
 
-	strncpy(rom_fname_loaded, rom_fname, sizeof(rom_fname_loaded)-1);
-	rom_fname_loaded[sizeof(rom_fname_loaded)-1] = 0;
-	rom_loaded = 1;
 	return 1;
 
-fail2:
-	menu_romload_end();
 fail:
-	if (rom != NULL) pm_close(rom);
+	if (rom_data)
+		free(rom_data);
+	menu_romload_end();
 	return 0;
 }
 
@@ -613,10 +740,11 @@ int emu_read_config(int game, int no_defaults)
 	char cfg[512];
 	int ret;
 
+	if (!no_defaults)
+		emu_set_defconfig();
+
 	if (!game)
 	{
-		if (!no_defaults)
-			emu_set_defconfig();
 		make_config_cfg(cfg);
 		ret = config_readsect(cfg, NULL);
 	}
@@ -765,18 +893,6 @@ void update_movie(void)
 	}
 }
 
-
-static size_t gzRead2(void *p, size_t _size, size_t _n, void *file)
-{
-	return gzread(file, p, _n);
-}
-
-
-static size_t gzWrite2(void *p, size_t _size, size_t _n, void *file)
-{
-	return gzwrite(file, p, _n);
-}
-
 static int try_ropen_file(const char *fname)
 {
 	FILE *f;
@@ -796,43 +912,53 @@ char *emu_get_save_fname(int load, int is_sram, int slot)
 
 	if (is_sram)
 	{
-		romfname_ext(saveFname, (PicoAHW&1) ? "brm"PATH_SEP : "srm"PATH_SEP, (PicoAHW&1) ? ".brm" : ".srm");
-		if (load) {
-			if (try_ropen_file(saveFname)) return saveFname;
-			// try in current dir..
-			romfname_ext(saveFname, NULL, (PicoAHW & PAHW_MCD) ? ".brm" : ".srm");
-			if (try_ropen_file(saveFname)) return saveFname;
-			return NULL; // give up
-		}
+		strcpy(ext, (PicoAHW & PAHW_MCD) ? ".brm" : ".srm");
+		romfname_ext(saveFname, (PicoAHW & PAHW_MCD) ? "brm"PATH_SEP : "srm"PATH_SEP, ext);
+		if (!load)
+			return saveFname;
+
+		if (try_ropen_file(saveFname))
+			return saveFname;
+
+		romfname_ext(saveFname, NULL, ext);
+		if (try_ropen_file(saveFname))
+			return saveFname;
 	}
 	else
 	{
+		const char *ext_main = (currentConfig.EmuOpt & EOPT_GZIP_SAVES) ? ".mds.gz" : ".mds";
+		const char *ext_othr = (currentConfig.EmuOpt & EOPT_GZIP_SAVES) ? ".mds" : ".mds.gz";
 		ext[0] = 0;
-		if(slot > 0 && slot < 10) sprintf(ext, ".%i", slot);
-		strcat(ext, (currentConfig.EmuOpt & EOPT_GZIP_SAVES) ? ".mds.gz" : ".mds");
+		if (slot > 0 && slot < 10)
+			sprintf(ext, ".%i", slot);
+		strcat(ext, ext_main);
+
+		if (!load) {
+			romfname_ext(saveFname, "mds" PATH_SEP, ext);
+			return saveFname;
+		}
+		else {
+			romfname_ext(saveFname, "mds" PATH_SEP, ext);
+			if (try_ropen_file(saveFname))
+				return saveFname;
 
-		romfname_ext(saveFname, "mds" PATH_SEP, ext);
-		if (load) {
-			if (try_ropen_file(saveFname)) return saveFname;
 			romfname_ext(saveFname, NULL, ext);
-			if (try_ropen_file(saveFname)) return saveFname;
-			// no gzipped states, search for non-gzipped
-			if (currentConfig.EmuOpt & EOPT_GZIP_SAVES)
-			{
-				ext[0] = 0;
-				if(slot > 0 && slot < 10) sprintf(ext, ".%i", slot);
-				strcat(ext, ".mds");
-
-				romfname_ext(saveFname, "mds"PATH_SEP, ext);
-				if (try_ropen_file(saveFname)) return saveFname;
-				romfname_ext(saveFname, NULL, ext);
-				if (try_ropen_file(saveFname)) return saveFname;
-			}
-			return NULL;
+			if (try_ropen_file(saveFname))
+				return saveFname;
+
+			// try the other ext
+			ext[0] = 0;
+			if (slot > 0 && slot < 10)
+				sprintf(ext, ".%i", slot);
+			strcat(ext, ext_othr);
+
+			romfname_ext(saveFname, "mds"PATH_SEP, ext);
+			if (try_ropen_file(saveFname))
+				return saveFname;
 		}
 	}
 
-	return saveFname;
+	return NULL;
 }
 
 int emu_check_save_file(int slot)
@@ -840,23 +966,6 @@ int emu_check_save_file(int slot)
 	return emu_get_save_fname(1, 0, slot) ? 1 : 0;
 }
 
-void emu_setSaveStateCbs(int gz)
-{
-	if (gz) {
-		areaRead  = gzRead2;
-		areaWrite = gzWrite2;
-		areaEof   = (areaeof *) gzeof;
-		areaSeek  = (areaseek *) gzseek;
-		areaClose = (areaclose *) gzclose;
-	} else {
-		areaRead  = (arearw *) fread;
-		areaWrite = (arearw *) fwrite;
-		areaEof   = (areaeof *) feof;
-		areaSeek  = (areaseek *) fseek;
-		areaClose = (areaclose *) fclose;
-	}
-}
-
 int emu_save_load_game(int load, int sram)
 {
 	int ret = 0;
@@ -880,7 +989,7 @@ int emu_save_load_game(int load, int sram)
 		int truncate = 1;
 		if (PicoAHW & PAHW_MCD)
 		{
-			if (PicoOpt&POPT_EN_MCD_RAMCART) {
+			if (PicoOpt & POPT_EN_MCD_RAMCART) {
 				sram_size = 0x12000;
 				sram_data = SRam.data;
 				if (sram_data)
@@ -891,8 +1000,7 @@ int emu_save_load_game(int load, int sram)
 				truncate  = 0; // the .brm may contain RAM cart data after normal brm
 			}
 		} else {
-			sram_size = SRam.end-SRam.start+1;
-			if(Pico.m.sram_reg & 4) sram_size=0x2000;
+			sram_size = SRam.size;
 			sram_data = SRam.data;
 		}
 		if (!sram_data) return 0; // SRam forcefully disabled for this game
@@ -927,34 +1035,13 @@ int emu_save_load_game(int load, int sram)
 	}
 	else
 	{
-		void *PmovFile = NULL;
-		if (strcmp(saveFname + strlen(saveFname) - 3, ".gz") == 0)
-		{
-			if( (PmovFile = gzopen(saveFname, load ? "rb" : "wb")) ) {
-				emu_setSaveStateCbs(1);
-				if (!load) gzsetparams(PmovFile, 9, Z_DEFAULT_STRATEGY);
-			}
-		}
-		else
-		{
-			if( (PmovFile = fopen(saveFname, load ? "rb" : "wb")) ) {
-				emu_setSaveStateCbs(0);
-			}
-		}
-		if(PmovFile) {
-			ret = PmovState(load ? 6 : 5, PmovFile);
-			areaClose(PmovFile);
-			PmovFile = 0;
-			if (load) Pico.m.dirtyPal=1;
+		ret = PicoState(saveFname, !load);
+		if (!ret) {
 #ifndef NO_SYNC
-			else sync();
+			if (!load) sync();
 #endif
-		}
-		else	ret = -1;
-		if (!ret)
 			emu_status_msg(load ? "STATE LOADED" : "STATE SAVED");
-		else
-		{
+		} else {
 			emu_status_msg(load ? "LOAD FAILED" : "SAVE FAILED");
 			ret = -1;
 		}
@@ -988,9 +1075,20 @@ void emu_set_fastforward(int set_on)
 	}
 }
 
-static void emu_msg_tray_open(void)
+static void emu_tray_open(void)
 {
-	emu_status_msg("CD tray opened");
+	engineState = PGS_TrayMenu;
+}
+
+static void emu_tray_close(void)
+{
+	emu_status_msg("CD tray closed.");
+}
+
+void emu_32x_startup(void)
+{
+	plat_video_toggle_renderer(0, 1, 0);
+	system_announce();
 }
 
 void emu_reset_game(void)
@@ -1120,9 +1218,9 @@ static void run_events_ui(unsigned int which)
 			PicoStateProgressCB = NULL;
 		}
 	}
-	if (which & PEV_SWITCH_RND)
+	if ((which & PEV_SWITCH_RND) && !(PicoAHW & PAHW_32X))
 	{
-		plat_video_toggle_renderer(1, 0);
+		plat_video_toggle_renderer(1, 0, 0);
 	}
 	if (which & (PEV_SSLOT_PREV|PEV_SSLOT_NEXT))
 	{
@@ -1212,8 +1310,8 @@ void emu_init(void)
 
 	PicoInit();
 	PicoMessage = plat_status_msg_busy_next;
-	PicoMCDopenTray = emu_msg_tray_open;
-	PicoMCDcloseTray = menu_loop_tray;
+	PicoMCDopenTray = emu_tray_open;
+	PicoMCDcloseTray = emu_tray_close;
 }
 
 void emu_finish(void)
@@ -1251,7 +1349,7 @@ void emu_loop(void)
 {
 	int pframes_done;		/* "period" frames, used for sync */
 	int frames_done, frames_shown;	/* actual frames for fps counter */
-	int oldmodes, target_fps, target_frametime;
+	int target_fps, target_frametime;
 	unsigned int timestamp_base = 0, timestamp_fps;
 	char *notice_msg = NULL;
 	char fpsbuff[24];
@@ -1260,8 +1358,8 @@ void emu_loop(void)
 	fpsbuff[0] = 0;
 
 	/* make sure we are in correct mode */
-	oldmodes = ((Pico.video.reg[12]&1)<<2) ^ 0xc;
 	Pico.m.dirtyPal = 1;
+	rendstatus_old = -1;
 
 	/* number of ticks per frame */
 	if (Pico.m.pal) {
@@ -1275,6 +1373,7 @@ void emu_loop(void)
 	// prepare CD buffer
 	if (PicoAHW & PAHW_MCD)
 		PicoCDBufferInit();
+	PicoLoopPrepare();
 
 	pemu_loop_prep();
 
@@ -1290,7 +1389,6 @@ void emu_loop(void)
 	{
 		unsigned int timestamp;
 		int diff, diff_lim;
-		int modes;
 
 		timestamp = get_ticks();
 		if (reset_timing) {
@@ -1317,13 +1415,6 @@ void emu_loop(void)
 			}
 		}
 
-		// check for mode changes
-		modes = ((Pico.video.reg[12]&1)<<2) | (Pico.video.reg[1]&8);
-		if (modes != oldmodes) {
-			oldmodes = modes;
-			pemu_video_mode_change(!(modes & 4), (modes & 8));
-		}
-
 		// second changed?
 		if (timestamp - timestamp_fps >= ms_to_ticks(1000))
 		{
@@ -1381,7 +1472,7 @@ void emu_loop(void)
 				if (!(currentConfig.EmuOpt & EOPT_NO_FRMLIMIT)) {
 					timestamp = get_ticks();
 					diff = timestamp - timestamp_base;
-					if (diff < diff_lim) // we are too fast
+					if (!reset_timing && diff < diff_lim) // we are too fast
 						plat_wait_till_us(timestamp_base + diff_lim);
 				}
 			}