mirror of
https://github.com/libretro/fuse-libretro.git
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520 lines
15 KiB
C
520 lines
15 KiB
C
/* zxs.c: Routines for .zxs snapshots
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Copyright (c) 1998,2003,2015 Philip Kendall
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along
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with this program; if not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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Author contact information:
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E-mail: philip-fuse@shadowmagic.org.uk
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*/
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#include "config.h"
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#include <string.h>
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#ifdef HAVE_ZLIB_H
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#define ZLIB_CONST
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#include <zlib.h>
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#endif /* #ifdef HAVE_ZLIB_H */
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#include "internals.h"
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static libspectrum_error
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read_chunk( libspectrum_snap *snap, const libspectrum_byte **buffer,
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const libspectrum_byte *end );
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typedef libspectrum_error (*read_chunk_fn)( libspectrum_snap *snap,
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int *compression,
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const libspectrum_byte **buffer,
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const libspectrum_byte *end,
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size_t data_length,
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int parameter );
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static libspectrum_error
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inflate_block( libspectrum_byte **uncompressed, size_t *uncompressed_length,
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const libspectrum_byte **compressed, size_t compressed_length )
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{
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#ifdef HAVE_ZLIB_H
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libspectrum_dword header_length, expected_crc32, actual_crc32;
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libspectrum_byte *zlib_buffer;
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unsigned long actual_length;
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int error;
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/* First, look at the compression header */
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header_length = libspectrum_read_dword( compressed );
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if( header_length != 12 ) {
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libspectrum_print_error( LIBSPECTRUM_ERROR_UNKNOWN,
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"zxs_inflate_block: unknown header length %lu",
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(unsigned long)header_length );
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return LIBSPECTRUM_ERROR_UNKNOWN;
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}
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compressed_length -= 12;
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expected_crc32 = libspectrum_read_dword( compressed );
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*uncompressed_length = libspectrum_read_dword( compressed );
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/* Some space to put the zlib header for decompression */
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zlib_buffer = libspectrum_new( libspectrum_byte, ( compressed_length + 6 ) );
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/* zlib's header */
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zlib_buffer[0] = 0x78; zlib_buffer[1] = 0xda;
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memcpy( &zlib_buffer[2], *compressed, compressed_length );
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*compressed += compressed_length;
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*uncompressed = libspectrum_new( libspectrum_byte, *uncompressed_length );
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actual_length = *uncompressed_length;
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error = uncompress( *uncompressed, &actual_length, zlib_buffer,
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compressed_length + 6 );
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/* At this point, we expect to get a Z_DATA_ERROR, as we don't have
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the Adler-32 checksum of the data. There is a 1 in 65521 chance
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that the random bytes will match, so we might (very rarely) get
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Z_OK */
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if( error != Z_DATA_ERROR && error != Z_OK ) {
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libspectrum_free( *uncompressed ); libspectrum_free( zlib_buffer );
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libspectrum_print_error( LIBSPECTRUM_ERROR_CORRUPT,
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"zxs_inflate_block: unexpected zlib error" );
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return LIBSPECTRUM_ERROR_CORRUPT;
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}
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if( *uncompressed_length != actual_length ) {
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libspectrum_free( *uncompressed ); libspectrum_free( zlib_buffer );
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libspectrum_print_error(
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LIBSPECTRUM_ERROR_CORRUPT,
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"zxs_inflate_block: block expanded to 0x%04lx, not the expected 0x%04lx bytes",
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actual_length, (unsigned long)*uncompressed_length
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);
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return LIBSPECTRUM_ERROR_CORRUPT;
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}
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libspectrum_free( zlib_buffer );
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actual_crc32 = crc32( 0, Z_NULL, 0 );
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actual_crc32 = crc32( actual_crc32, *uncompressed, *uncompressed_length );
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if( actual_crc32 != expected_crc32 ) {
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libspectrum_free( *uncompressed );
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libspectrum_print_error(
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LIBSPECTRUM_ERROR_CORRUPT,
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"zxs_inflate_block: crc 0x%08x does not match expected 0x%08x",
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actual_crc32, expected_crc32
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);
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return LIBSPECTRUM_ERROR_CORRUPT;
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}
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return LIBSPECTRUM_ERROR_NONE;
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#else /* #ifdef HAVE_ZLIB_H */
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/* No zlib, so can't inflate the block */
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return LIBSPECTRUM_ERROR_UNKNOWN;
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#endif /* #ifdef HAVE_ZLIB_H */
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}
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static libspectrum_error
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read_riff_chunk( libspectrum_snap *snap, int *compression GCC_UNUSED,
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const libspectrum_byte **buffer, const libspectrum_byte *end,
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size_t data_length GCC_UNUSED, int parameter GCC_UNUSED)
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{
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char id[5];
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libspectrum_error error;
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if( end - *buffer < 4 ) {
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libspectrum_print_error(
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LIBSPECTRUM_ERROR_CORRUPT,
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"zxs_read_riff_chunk: not enough data for form type"
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);
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return LIBSPECTRUM_ERROR_CORRUPT;
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}
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memcpy( id, *buffer, 4 ); id[4] = '\0'; *buffer += 4;
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if( strcmp( id, "SNAP" ) ) {
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libspectrum_print_error( LIBSPECTRUM_ERROR_UNKNOWN,
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"zxs_read_riff_chunk: unknown form type '%s'",
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id );
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return LIBSPECTRUM_ERROR_UNKNOWN;
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}
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while( *buffer < end ) {
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error = read_chunk( snap, buffer, end );
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if( error ) return error;
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}
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return LIBSPECTRUM_ERROR_NONE;
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}
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static libspectrum_error
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read_fmtz_chunk( libspectrum_snap *snap, int *compression,
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const libspectrum_byte **buffer,
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const libspectrum_byte *end GCC_UNUSED,
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size_t data_length, int parameter GCC_UNUSED )
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{
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libspectrum_word model;
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if( data_length != 8 ) {
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libspectrum_print_error( LIBSPECTRUM_ERROR_UNKNOWN,
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"zxs_read_fmtz_chunk: unknown length %lu",
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(unsigned long)data_length );
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return LIBSPECTRUM_ERROR_UNKNOWN;
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}
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*buffer += 2; /* Skip version number */
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model = libspectrum_read_word( buffer );
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switch( model ) {
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case 0x0010: case 0x0020:
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libspectrum_snap_set_machine( snap, LIBSPECTRUM_MACHINE_48 );
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break;
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case 0x0030:
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libspectrum_snap_set_machine( snap, LIBSPECTRUM_MACHINE_128 );
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break;
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case 0x0040:
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libspectrum_snap_set_machine( snap, LIBSPECTRUM_MACHINE_PLUS2 );
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break;
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case 0x0050:
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libspectrum_snap_set_machine( snap, LIBSPECTRUM_MACHINE_PLUS2A );
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break;
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case 0x0060:
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libspectrum_snap_set_machine( snap, LIBSPECTRUM_MACHINE_PLUS3 );
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break;
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default:
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libspectrum_print_error(
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LIBSPECTRUM_ERROR_UNKNOWN,
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"zxs_read_fmtz_chunk: unknown machine type 0x%04x", model
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);
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return LIBSPECTRUM_ERROR_UNKNOWN;
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}
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*buffer += 2; /* Skip hardware flags */
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*compression = libspectrum_read_word( buffer );
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switch( *compression ) {
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case 0x0008: /* Deflation */
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*compression = 1; break;
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case 0xffff: /* Not compressed */
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*compression = 0; break;
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default:
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libspectrum_print_error(
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LIBSPECTRUM_ERROR_UNKNOWN,
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"zxs_read_fmtz_chunk: unknown compression type 0x%04x", *compression
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);
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return LIBSPECTRUM_ERROR_UNKNOWN;
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}
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return LIBSPECTRUM_ERROR_NONE;
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}
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static libspectrum_error
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read_rz80_chunk( libspectrum_snap *snap, int *compression GCC_UNUSED,
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const libspectrum_byte **buffer,
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const libspectrum_byte *end GCC_UNUSED,
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size_t data_length, int parameter GCC_UNUSED )
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{
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if( data_length != 33 ) {
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libspectrum_print_error( LIBSPECTRUM_ERROR_UNKNOWN,
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"zxs_read_rZ80_chunk: unknown length %lu",
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(unsigned long)data_length );
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return LIBSPECTRUM_ERROR_UNKNOWN;
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}
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libspectrum_snap_set_a ( snap, **buffer ); (*buffer)++;
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libspectrum_snap_set_f ( snap, **buffer ); (*buffer)++;
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libspectrum_snap_set_bc ( snap, libspectrum_read_word( buffer ) );
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libspectrum_snap_set_de ( snap, libspectrum_read_word( buffer ) );
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libspectrum_snap_set_hl ( snap, libspectrum_read_word( buffer ) );
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libspectrum_snap_set_a_ ( snap, **buffer ); (*buffer)++;
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libspectrum_snap_set_f_ ( snap, **buffer ); (*buffer)++;
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libspectrum_snap_set_bc_ ( snap, libspectrum_read_word( buffer ) );
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libspectrum_snap_set_de_ ( snap, libspectrum_read_word( buffer ) );
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libspectrum_snap_set_hl_ ( snap, libspectrum_read_word( buffer ) );
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libspectrum_snap_set_ix ( snap, libspectrum_read_word( buffer ) );
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libspectrum_snap_set_iy ( snap, libspectrum_read_word( buffer ) );
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libspectrum_snap_set_pc ( snap, libspectrum_read_word( buffer ) );
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libspectrum_snap_set_sp ( snap, libspectrum_read_word( buffer ) );
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libspectrum_snap_set_i ( snap, **buffer ); (*buffer)++;
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libspectrum_snap_set_r ( snap, **buffer ); (*buffer)++;
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libspectrum_snap_set_iff1( snap, **buffer ); (*buffer)++;
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libspectrum_snap_set_iff2( snap, **buffer ); (*buffer)++;
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libspectrum_snap_set_im ( snap, **buffer ); (*buffer)++;
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libspectrum_snap_set_tstates( snap, libspectrum_read_dword( buffer ) );
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return LIBSPECTRUM_ERROR_NONE;
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}
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static libspectrum_error
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read_r048_chunk( libspectrum_snap *snap, int *compression GCC_UNUSED,
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const libspectrum_byte **buffer,
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const libspectrum_byte *end GCC_UNUSED,
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size_t data_length, int parameter GCC_UNUSED )
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{
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if( data_length != 9 ) {
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libspectrum_print_error(
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LIBSPECTRUM_ERROR_UNKNOWN,
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"zxs_read_r048_chunk: unknown length %lu", (unsigned long)data_length
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);
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return LIBSPECTRUM_ERROR_UNKNOWN;
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}
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libspectrum_snap_set_out_ula( snap, **buffer ); (*buffer)++;
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*buffer += 8; /* Skip key data */
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return LIBSPECTRUM_ERROR_NONE;
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}
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static libspectrum_error
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read_r128_chunk( libspectrum_snap *snap, int *compression GCC_UNUSED,
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const libspectrum_byte **buffer,
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const libspectrum_byte *end GCC_UNUSED,
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size_t data_length, int parameter GCC_UNUSED )
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{
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size_t i;
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if( data_length != 18 ) {
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libspectrum_print_error( LIBSPECTRUM_ERROR_UNKNOWN,
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"zxs_read_r128_chunk: unknown length %lu",
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(unsigned long)data_length );
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return LIBSPECTRUM_ERROR_UNKNOWN;
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}
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libspectrum_snap_set_out_128_memoryport( snap, **buffer ); (*buffer)++;
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libspectrum_snap_set_out_ay_registerport( snap, **buffer ); (*buffer)++;
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for( i = 0; i < 16; i++ ) {
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libspectrum_snap_set_ay_registers( snap, i, **buffer ); (*buffer)++;
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}
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return LIBSPECTRUM_ERROR_NONE;
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}
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static libspectrum_error
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read_rplus3_chunk( libspectrum_snap *snap, int *compression GCC_UNUSED,
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const libspectrum_byte **buffer,
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const libspectrum_byte *end GCC_UNUSED, size_t data_length,
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int parameter GCC_UNUSED )
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{
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if( data_length != 1 ) {
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libspectrum_print_error( LIBSPECTRUM_ERROR_UNKNOWN,
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"zxs_read_rplus3_chunk: unknown length %lu",
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(unsigned long)data_length );
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return LIBSPECTRUM_ERROR_UNKNOWN;
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}
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libspectrum_snap_set_out_plus3_memoryport( snap, **buffer ); (*buffer)++;
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return LIBSPECTRUM_ERROR_NONE;
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}
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static libspectrum_error
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read_ram_chunk( libspectrum_snap *snap, int *compression,
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const libspectrum_byte **buffer,
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const libspectrum_byte *end GCC_UNUSED,
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size_t data_length, int parameter )
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{
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int page = parameter;
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libspectrum_byte *buffer2; size_t uncompressed_length;
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libspectrum_error error;
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if( *compression ) {
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error = inflate_block( &buffer2, &uncompressed_length,
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buffer, data_length );
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if( error ) return error;
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if( uncompressed_length != 0x4000 ) {
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libspectrum_free( buffer2 );
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libspectrum_print_error(
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LIBSPECTRUM_ERROR_CORRUPT,
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"zxs_read_ram_chunk: page %d does not expand to 0x4000 bytes", page
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);
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return LIBSPECTRUM_ERROR_MEMORY;
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}
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} else { /* Uncompressed data */
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if( data_length != 0x4000 ) {
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libspectrum_print_error(
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LIBSPECTRUM_ERROR_UNKNOWN,
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"zxs_read_ram_chunk: page %d has unknown length %lu", page,
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(unsigned long)data_length
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);
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return LIBSPECTRUM_ERROR_UNKNOWN;
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}
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buffer2 = libspectrum_new( libspectrum_byte, 0x4000 );
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memcpy( buffer2, buffer, 0x4000 ); *buffer += 0x4000;
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}
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libspectrum_snap_set_pages( snap, page, buffer2 );
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return LIBSPECTRUM_ERROR_NONE;
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}
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static libspectrum_error
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skip_chunk( libspectrum_snap *snap GCC_UNUSED, int *compression GCC_UNUSED,
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const libspectrum_byte **buffer,
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const libspectrum_byte *end GCC_UNUSED,
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size_t data_length, int parameter GCC_UNUSED )
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{
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*buffer += data_length;
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return LIBSPECTRUM_ERROR_NONE;
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}
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struct read_chunk_t {
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const char *id;
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read_chunk_fn function;
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int parameter;
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};
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static struct read_chunk_t read_chunks[] = {
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{ "RIFF", read_riff_chunk, 0 },
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{ "fmtz", read_fmtz_chunk, 0 },
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{ "rZ80", read_rz80_chunk, 0 },
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{ "r048", read_r048_chunk, 0 },
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{ "r128", read_r128_chunk, 0 },
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{ "r+3 ", read_rplus3_chunk, 0 },
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{ "ram0", read_ram_chunk, 0 },
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{ "ram1", read_ram_chunk, 1 },
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{ "ram2", read_ram_chunk, 2 },
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{ "ram3", read_ram_chunk, 3 },
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{ "ram4", read_ram_chunk, 4 },
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{ "ram5", read_ram_chunk, 5 },
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{ "ram6", read_ram_chunk, 6 },
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{ "ram7", read_ram_chunk, 7 },
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{ "LIST", skip_chunk, 0 },
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};
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static libspectrum_error
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read_chunk_header( char *id, libspectrum_dword *data_length,
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const libspectrum_byte **buffer,
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const libspectrum_byte *end )
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{
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if( end - *buffer < 8 ) {
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libspectrum_print_error(
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LIBSPECTRUM_ERROR_CORRUPT,
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"zxs_read_chunk_header: not enough data for chunk header"
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);
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return LIBSPECTRUM_ERROR_CORRUPT;
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}
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memcpy( id, *buffer, 4 ); id[4] = '\0'; *buffer += 4;
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*data_length = libspectrum_read_dword( buffer );
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return LIBSPECTRUM_ERROR_NONE;
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}
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static libspectrum_error
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read_chunk( libspectrum_snap *snap, const libspectrum_byte **buffer,
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const libspectrum_byte *end )
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{
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char id[5];
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libspectrum_dword data_length;
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libspectrum_error error;
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size_t i; int done;
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int compression;
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error = read_chunk_header( id, &data_length, buffer, end );
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if( error ) return error;
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if( *buffer + data_length > end ) {
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libspectrum_print_error(
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LIBSPECTRUM_ERROR_CORRUPT,
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"zxs_read_chunk: chunk length goes beyond end of file"
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);
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return LIBSPECTRUM_ERROR_CORRUPT;
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}
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done = 0;
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for( i = 0; !done && i < ARRAY_SIZE( read_chunks ); i++ ) {
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if( !strcmp( id, read_chunks[i].id ) ) {
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error = read_chunks[i].function( snap, &compression, buffer, end,
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data_length, read_chunks[i].parameter );
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if( error ) return error;
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done = 1;
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}
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}
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if( !done ) {
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libspectrum_print_error( LIBSPECTRUM_ERROR_UNKNOWN,
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"zxs_read_chunk: unknown chunk id '%s'", id );
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*buffer += data_length;
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}
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if( data_length % 2 ) (*buffer)++;
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return LIBSPECTRUM_ERROR_NONE;
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}
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libspectrum_error
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libspectrum_zxs_read( libspectrum_snap *snap, const libspectrum_byte *buffer,
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size_t length )
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{
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libspectrum_error error;
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/* Set machine type in case it's not set later */
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libspectrum_snap_set_machine( snap, LIBSPECTRUM_MACHINE_48 );
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error = read_chunk( snap, &buffer, buffer + length );
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if( error ) {
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/* Tidy up any RAM pages we may have allocated */
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size_t i;
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for( i = 0; i < 8; i++ ) {
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libspectrum_byte *page = libspectrum_snap_pages( snap, i );
|
|
if( page ) {
|
|
libspectrum_free( page );
|
|
libspectrum_snap_set_pages( snap, i, NULL );
|
|
}
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
return LIBSPECTRUM_ERROR_NONE;
|
|
}
|