/*
  * UAE - The Un*x Amiga Emulator
  *
  * Save/restore emulator state
  *
  * (c) 1999-2001 Toni Wilen
  *
  * see below for ASF-structure
  */

 /* Features:
  *
  * - full CPU state (68000/68010/68020, no FPU)
  * - full CIA-A and CIA-B state (with all internal registers)
  * - saves all custom registers and audio internal state but not all registers are restored yet.
  * - only Chip-ram and Bogo-ram are saved and restored.
  * - disk drive type, imagefile, track and motor state
  * - Kickstart ROM version, address and size is saved. This data is not used during restore yet.
  */

 /* Notes:
  *
  * - blitter state is not saved, blitter is forced to finish immediately if it
  *   was active
  * - disk DMA state is completely saved (I hope so..)
  * - does not ask for statefile name and description. Currently uses DF0's disk
  *   image name (".adf" is replaced with ".asf")
  * - only Amiga state is restored, harddisk support, autoconfig, expansion boards etc..
  *   are not saved/restored (and probably never will).
  * - use this for saving games that can't be saved to disk
  */

 /* Usage :
  *
  * save:
  *
  * set savestate_state = STATE_DOSAVE, savestate_filename = "..."
  *
  * restore:
  *
  * set savestate_state = STATE_DORESTORE, savestate_filename = "..."
  *
  */

#include "sysconfig.h"
#include "sysdeps.h"

#include "options.h"
#include "memory.h"
#include "zfile.h"
#include "savestate.h"
#include "gui.h"

int savestate_state;

char *savestate_filename;
struct zfile *savestate_file;

/* functions for reading/writing bytes, shorts and longs in big-endian
 * format independent of host machine's endianess */

void save_u32_func (uae_u8 **dstp, uae_u32 v)
{
    uae_u8 *dst = *dstp;
    *dst++ = (uae_u8)(v >> 24);
    *dst++ = (uae_u8)(v >> 16);
    *dst++ = (uae_u8)(v >> 8);
    *dst++ = (uae_u8)(v >> 0);
    *dstp = dst;
}
void save_u64_func (uae_u8 **dstp, uae_u64 v)
{
    save_u32_func (dstp, (uae_u32)(v >> 32));
    save_u32_func (dstp, (uae_u32)v);
}
void save_u16_func (uae_u8 **dstp, uae_u16 v)
{
    uae_u8 *dst = *dstp;
    *dst++ = (uae_u8)(v >> 8);
    *dst++ = (uae_u8)(v >> 0);
    *dstp = dst;
}
void save_u8_func (uae_u8 **dstp, uae_u8 v)
{
    uae_u8 *dst = *dstp;
    *dst++ = v;
    *dstp = dst;
}
void save_string_func (uae_u8 **dstp, const char *from)
{
    uae_u8 *dst = *dstp;
    while (*from)
	*dst++ = *from++;
    *dst++ = 0;
    *dstp = dst;
}

uae_u32 restore_u32_func (const uae_u8 **dstp)
{
    uae_u32 v;
    const uae_u8 *dst = *dstp;
    v = (dst[0] << 24) | (dst[1] << 16) | (dst[2] << 8) | (dst[3]);
    *dstp = dst + 4;
    return v;
}
uae_u64 restore_u64_func (const uae_u8 **dstp)
{
    uae_u64 v;

    v = restore_u32_func (dstp);
    v <<= 32;
    v |= restore_u32_func (dstp);
    return v;
}
uae_u16 restore_u16_func (const uae_u8 **dstp)
{
    uae_u16 v;
    const uae_u8 *dst = *dstp;
    v=(dst[0] << 8) | (dst[1]);
    *dstp = dst + 2;
    return v;
}
uae_u8 restore_u8_func (const uae_u8 **dstp)
{
    uae_u8 v;
    const uae_u8 *dst = *dstp;
    v = dst[0];
    *dstp = dst + 1;
    return v;
}
char *restore_string_func (const uae_u8 **dstp)
{
    int len;
    uae_u8 v;
    const uae_u8 *dst = *dstp;
    char *top, *to;
    len = strlen ((const char *)dst) + 1;
    top = to = malloc (len);
    do {
	v = *dst++;
	*top++ = v;
    } while (v);
    *dstp = dst;
    return to;
}

/* read and write IFF-style hunks */

static void save_chunk (struct zfile *f, uae_u8 *chunk, long len, const char *name)
{
    uae_u8 tmp[4], *dst;
    uae_u8 zero[4]= { 0, 0, 0, 0 };

    if (!chunk)
	return;

    /* chunk name */
    zfile_fwrite (name, 1, 4, f);
    /* chunk size */
    dst = &tmp[0];
    save_u32 (len + 4 + 4 + 4);
    zfile_fwrite (&tmp[0], 1, 4, f);
    /* chunk flags */
    dst = &tmp[0];
    save_u32 (0);
    zfile_fwrite (&tmp[0], 1, 4, f);
    /* chunk data */
    zfile_fwrite (chunk, 1, len, f);
    /* alignment */
    len = 4 - (len & 3);
    if (len)
	zfile_fwrite (zero, 1, len, f);
}

static uae_u8 *restore_chunk (struct zfile *f, char *name, long *len, long *filepos)
{
    uae_u8 tmp[4], dummy[4], *mem;
    const uae_u8 *src;
    uae_u32 flags;
    long len2;

    /* chunk name */
    zfile_fread (name, 1, 4, f);
    name[4] = 0;
    /* chunk size */
    zfile_fread (tmp, 1, 4, f);
    src = tmp;
    len2 = restore_u32 () - 4 - 4 - 4;
    if (len2 < 0)
	len2 = 0;
    *len = len2;
    if (len2 == 0)
	return 0;

    /* chunk flags */
    zfile_fread (tmp, 1, 4, f);
    src = tmp;
    flags = restore_u32 ();

    *filepos = zfile_ftell (f) - 4 - 4;

    /* chunk data.  RAM contents will be loaded during the reset phase,
       no need to malloc multiple megabytes here.  */
    if (strcmp (name, "CRAM") != 0
	&& strcmp (name, "BRAM") != 0
	&& strcmp (name, "FRAM") != 0
	&& strcmp (name, "ZRAM") != 0
	&& strcmp (name, "A3K1") != 0
	&& strcmp (name, "A3K2") != 0)
    {
	mem = malloc (len2);
	zfile_fread (mem, 1, len2, f);
    } else {
	mem = 0;
	zfile_fseek (f, len2, SEEK_CUR);
    }

    /* alignment */
    len2 = 4 - (len2 & 3);
    if (len2)
	zfile_fread (dummy, 1, len2, f);
    return mem;
}

void restore_ram (size_t filepos, uae_u8 *memory)
{
    uae_u8 tmp[8];
    uae_u8 *src = tmp;
    int size, fullsize;
    uae_u32 flags;

    zfile_fseek (savestate_file, filepos, SEEK_SET);
    zfile_fread (tmp, 1, sizeof(tmp), savestate_file);
    size = restore_u32 ();
    flags = restore_u32 ();
    size -= 4 + 4 + 4;
    zfile_fread (memory, 1, size, savestate_file);
}

static void restore_header (const uae_u8 *src)
{
    char *emuname, *emuversion, *description;

    restore_u32 ();
    emuname = restore_string ();
    emuversion = restore_string ();
    description = restore_string ();
    write_log ("Saved with: '%s %s', description: '%s'\n",
	emuname, emuversion, description);
    free (description);
    free (emuversion);
    free (emuname);
}

/* restore all subsystems */

void restore_state (const char *filename)
{
    struct zfile *f;
    const uae_u8 *chunk, *end;
    char name[5];
    long len;
    long filepos;

    chunk = 0;
    f = zfile_open (filename, "rb");
    if (!f)
	goto error;

    chunk = restore_chunk (f, name, &len, &filepos);
    if (!chunk || memcmp (name, "ASF ", 4)) {
	write_log ("%s is not an AmigaStateFile\n",filename);
	goto error;
    }
    savestate_file = f;
    restore_header (chunk);
    free (chunk);
    changed_prefs.bogomem_size = 0;
    changed_prefs.chipmem_size = 0;
    changed_prefs.fastmem_size = 0;
    changed_prefs.gfxmem_size = 0;
    changed_prefs.z3fastmem_size = 0;
    changed_prefs.mbresmem_low_size = 0;
    changed_prefs.mbresmem_high_size = 0;
    savestate_state = STATE_RESTORE;
    for (;;) {
	chunk = restore_chunk (f, name, &len, &filepos);
	write_log ("Chunk '%s' size %d\n", name, len);
	if (!strcmp (name, "END "))
	    break;
	if (!strcmp (name, "CRAM")) {
	    restore_cram (len, filepos);
	    continue;
	} else if (!strcmp (name, "BRAM")) {
	    restore_bram (len, filepos);
	    continue;
	} else if (!strcmp (name, "A3K1")) {
	    restore_a3000lram (len, filepos);
	    continue;
	} else if (!strcmp (name, "A3K2")) {
	    restore_a3000hram (len, filepos);
	    continue;
	} else if (!strcmp (name, "FRAM")) {
	    restore_fram (len, filepos);
	    continue;
	} else if (!strcmp (name, "ZRAM")) {
	    restore_zram (len, filepos);
	    continue;
	}

	if (!strcmp (name, "CPU "))
	    end = restore_cpu (chunk);
	else if (!strcmp (name, "AGAC"))
	    end = restore_custom_agacolors (chunk);
	else if (!strcmp (name, "SPR0"))
	    end = restore_custom_sprite (0, chunk);
	else if (!strcmp (name, "SPR1"))
	    end = restore_custom_sprite (1, chunk);
	else if (!strcmp (name, "SPR2"))
	    end = restore_custom_sprite (2, chunk);
	else if (!strcmp (name, "SPR3"))
	    end = restore_custom_sprite (3, chunk);
	else if (!strcmp (name, "SPR4"))
	    end = restore_custom_sprite (4, chunk);
	else if (!strcmp (name, "SPR5"))
	    end = restore_custom_sprite (5, chunk);
	else if (!strcmp (name, "SPR6"))
	    end = restore_custom_sprite (6, chunk);
	else if (!strcmp (name, "SPR7"))
	    end = restore_custom_sprite (7, chunk);
	else if (!strcmp (name, "CIAA"))
	    end = restore_cia (0, chunk);
	else if (!strcmp (name, "CIAB"))
	    end = restore_cia (1, chunk);
	else if (!strcmp (name, "CHIP"))
	    end = restore_custom (chunk);
	else if (!strcmp (name, "AUD0"))
	    end = restore_audio (0, chunk);
	else if (!strcmp (name, "AUD1"))
	    end = restore_audio (1, chunk);
	else if (!strcmp (name, "AUD2"))
	    end = restore_audio (2, chunk);
	else if (!strcmp (name, "AUD3"))
	    end = restore_audio (3, chunk);
#if 0
	else if (!strcmp (name, "BLIT"))
	    end = restore_custom_blitter (chunk);
#endif
	else if (!strcmp (name, "DISK"))
	    end = restore_floppy (chunk);
	else if (!strcmp (name, "DSK0"))
	    end = restore_disk (0, chunk);
	else if (!strcmp (name, "DSK1"))
	    end = restore_disk (1, chunk);
	else if (!strcmp (name, "DSK2"))
	    end = restore_disk (2, chunk);
	else if (!strcmp (name, "DSK3"))
	    end = restore_disk (3, chunk);
	else if (!strcmp (name, "EXPA"))
	    end = restore_expansion (chunk);
	else if (!strcmp (name, "ROM "))
	    end = restore_rom (chunk);
	else
	    write_log ("unknown chunk '%s' size %d bytes\n", name, len);
	if (len != end - chunk)
	    write_log ("Chunk '%s' total size %d bytes but read %d bytes!\n",
		       name, len, end - chunk);
	free (chunk);
    }
    gui_update ();
    return;

    error:
    savestate_state = 0;
    savestate_file = 0;
    if (chunk)
	free (chunk);
    if (f)
	zfile_fclose (f);
}

void savestate_restore_finish (void)
{
    if (savestate_state != STATE_RESTORE)
	return;
    zfile_fclose (savestate_file);
    savestate_file = 0;
    savestate_state = 0;
}

/* Save all subsystems  */

void save_state (const char *filename, const char *description)
{
    uae_u8 header[1000];
    char tmp[100];
    uae_u8 *dst;
    struct zfile *f;
    int len,i;
    char name[5];

    f = zfile_open (filename, "wb");
    if (!f)
	return;

    dst = header;
    save_u32 (0);
    save_string ("UAE");
    save_string (PACKAGE_VERSION);
    save_string (description);
    save_chunk (f, header, dst-header, "ASF ");

    dst = save_cpu (&len, 0);
    save_chunk (f, dst, len, "CPU ");
    free (dst);

    strcpy (name, "DSKx");
    for (i = 0; i < 4; i++) {
	dst = save_disk (i, &len, 0);
	if (dst) {
	    name[3] = i + '0';
	    save_chunk (f, dst, len, name);
	    free (dst);
	}
    }
    dst = save_floppy (&len, 0);
    save_chunk (f, dst, len, "DISK");
    free (dst);

    dst = save_custom (&len, 0, 0);
    save_chunk (f, dst, len, "CHIP");
    free (dst);

#if 0
    dst = save_custom_blitter (&len);
    save_chunk (f, dst, len, "BLIT");
    free (dst);
#endif

    dst = save_custom_agacolors (&len, 0);
    save_chunk (f, dst, len, "AGAC");
    free (dst);

    strcpy (name, "SPRx");
    for (i = 0; i < 8; i++) {
	dst = save_custom_sprite (i, &len);
	name[3] = i + '0';
	save_chunk (f, dst, len, name);
	free (dst);
    }

    strcpy (name, "AUDx");
    for (i = 0; i < 4; i++) {
	dst = save_audio (i, &len);
	name[3] = i + '0';
	save_chunk (f, dst, len, name);
	free (dst);
    }

    dst = save_cia (0, &len, 0);
    save_chunk (f, dst, len, "CIAA");
    free (dst);

    dst = save_cia (1, &len, 0);
    save_chunk (f, dst, len, "CIAB");
    free (dst);

    dst = save_expansion (&len, 0);
    save_chunk (f, dst, len, "EXPA");
    dst = save_cram (&len);
    save_chunk (f, dst, len, "CRAM");
    dst = save_bram (&len);
    save_chunk (f, dst, len, "BRAM");
    dst = save_a3000lram (&len);
    save_chunk (f, dst, len, "A3K1");
    dst = save_a3000hram (&len);
    save_chunk (f, dst, len, "A3K2");
    dst = save_fram (&len);
    save_chunk (f, dst, len, "FRAM");
    dst = save_zram (&len);
    save_chunk (f, dst, len, "ZRAM");

    dst = save_rom (1, &len, 0);
    do {
	if (!dst)
	    break;
	save_chunk (f, dst, len, "ROM ");
	free (dst);
    } while ((dst = save_rom (0, &len, 0)));

    zfile_fwrite ("END ", 1, 4, f);
    zfile_fwrite ("\0\0\0\08", 1, 4, f);
    write_log ("Save of '%s' complete\n", filename);
    zfile_fclose (f);
}

/*

My (Toni Wilen <twilen@arabuusimiehet.com>)
proposal for Amiga-emulators' state-save format

Feel free to comment...

This is very similar to IFF-fileformat
Every hunk must end to 4 byte boundary,
fill with zero bytes if needed

version 0.7

HUNK HEADER (beginning of every hunk)

	hunk name (4 ascii-characters)
	hunk size (including header)
	hunk flags

	bit 0 = chunk contents are compressed with zlib (maybe RAM chunks only?)

HEADER

	"ASF " (AmigaStateFile)

	statefile version
	emulator name ("uae", "fellow" etc..)
	emulator version string (example: "0.8.15")
	free user writable comment string

CPU

	 "CPU "

	CPU model               4 (68000,68010 etc..)
	CPU typeflags           bit 0=EC-model or not
	D0-D7                   8*4=32
	A0-A6                   7*4=32
	PC                      4
	prefetch address        4
	prefetch data           4
	USP                     4
	ISP                     4
	SR/CCR                  2
	flags                   4 (bit 0=CPU was HALTed)

	CPU specific registers

	68000: SR/CCR is last saved register
	68010: save also DFC,SFC and VBR
	68020: all 68010 registers and CAAR,CACR and MSP
	etc..

	DFC                     4 (010+)
	SFC                     4 (010+)
	VBR                     4 (010+)

	CAAR                    4 (020-030)
	CACR                    4 (020+)
	MSP                     4 (020+)

MMU (when and if MMU is supported in future..)

	MMU model               4 (68851,68030,68040)

	// 68040 fields

	ITT0                    4
	ITT1                    4
	DTT0                    4
	DTT1                    4
	URP                     4
	SRP                     4
	MMUSR                   4
	TC                      2


FPU (only if used)

	"FPU "

	FPU model               4 (68881 or 68882)
	FPU typeflags           4 (keep zero)

	FP0-FP7                 4+2 (80 bits)
	FPCR                    4
	FPSR                    4
	FPIAR                   4

CUSTOM CHIPS

	"CHIP"

	chipset flags   4      OCS=0,ECSAGNUS=1,ECSDENISE=2,AGA=4
			       ECSAGNUS and ECSDENISE can be combined

	DFF000-DFF1FF   352    (0x120 - 0x17f and 0x0a0 - 0xdf excluded)

	sprite registers (0x120 - 0x17f) saved with SPRx chunks
	audio registers (0x0a0 - 0xdf) saved with AUDx chunks

AGA COLORS

	"AGAC"

	AGA color               8 banks * 32 registers *
	registers               LONG (XRGB) = 1024

SPRITE

	"SPR0" - "SPR7"


	SPRxPT                  4
	SPRxPOS                 2
	SPRxCTL                 2
	SPRxDATA                2
	SPRxDATB                2
	AGA sprite DATA/DATB    3 * 2 * 2
	sprite "armed" status   1

	sprites maybe armed in non-DMA mode
	use bit 0 only, other bits are reserved


AUDIO
	"AUD0" "AUD1" "AUD2" "AUD3"

	audio state             1
	machine mode
	AUDxVOL                 1
	irq?                    1
	data_written?           1
	internal AUDxLEN        2
	AUDxLEN                 2
	internal AUDxPER        2
	AUDxPER                 2
	internal AUDxLC         4
	AUDxLC                  4
	evtime?                 4

BLITTER

	"BLIT"

	internal blitter state

	blitter running         1
	anything else?

CIA

	"CIAA" and "CIAB"

	BFE001-BFEF01   16*1 (CIAA)
	BFD000-BFDF00   16*1 (CIAB)

	internal registers

	IRQ mask (ICR)  1 BYTE
	timer latches   2 timers * 2 BYTES (LO/HI)
	latched tod     3 BYTES (LO/MED/HI)
	alarm           3 BYTES (LO/MED/HI)
	flags           1 BYTE
			bit 0=tod latched (read)
			bit 1=tod stopped (write)
	div10 counter	1 BYTE

FLOPPY DRIVES

	"DSK0" "DSK1" "DSK2" "DSK3"

	drive state

	drive ID-word           4
	state                   1 (bit 0: motor on, bit 1: drive disabled)
	rw-head track           1
	dskready                1
	id-mode                 1 (ID mode bit number 0-31)
	floppy information

	bits from               4
	beginning of track
	CRC of disk-image       4 (used during restore to check if image
				  is correct)
	disk-image              null-terminated
	file name

INTERNAL FLOPPY CONTROLLER STATUS

	"DISK"

	current DMA word        2
	DMA word bit offset     1
	WORDSYNC found          1 (no=0,yes=1)
	hpos of next bit        1
	DSKLENGTH status        0=off,1=written once,2=written twice

RAM SPACE

	"xRAM" (CRAM = chip, BRAM = bogo, FRAM = fast, ZFRAM = Z3)

	start address           4 ("bank"=chip/slow/fast etc..)
	of RAM "bank"
	RAM "bank" size         4
	RAM flags               4
	RAM "bank" contents

ROM SPACE

	"ROM "

	ROM start               4
	address
	size of ROM             4
	ROM type                4 KICK=0
	ROM flags               4
	ROM version             2
	ROM revision            2
	ROM CRC                 4 see below
	ROM-image               null terminated, see below
	ID-string
	ROM contents            (Not mandatory, use hunk size to check if
				this hunk contains ROM data or not)

	Kickstart ROM:
	 ID-string is "Kickstart x.x"
	 ROM version: version in high word and revision in low word
	 Kickstart ROM version and revision can be found from ROM start
	 + 12 (version) and +14 (revision)

	ROM version and CRC is only meant for emulator to automatically
	find correct image from its ROM-directory during state restore.

	Usually saving ROM contents is not good idea.


END
	hunk "END " ends, remember hunk size 8!


EMULATOR SPECIFIC HUNKS

Read only if "emulator name" in header is same as used emulator.
Maybe useful for configuration?

misc:

- save only at position 0,0 before triggering VBLANK interrupt
- all data must be saved in bigendian format
- should we strip all paths from image file names?

*/