static void
write_header( libspectrum_byte **buffer, libspectrum_byte **ptr,
size_t *length, libspectrum_snap *snap )
{
libspectrum_make_room( buffer, LIBSPECTRUM_SNA_HEADER_LENGTH, ptr, length );
*(*ptr)++ = libspectrum_snap_i ( snap );
libspectrum_write_word( ptr, libspectrum_snap_hl_( snap ) );
libspectrum_write_word( ptr, libspectrum_snap_de_( snap ) );
libspectrum_write_word( ptr, libspectrum_snap_bc_( snap ) );
*(*ptr)++ = libspectrum_snap_f_( snap );
*(*ptr)++ = libspectrum_snap_a_( snap );
libspectrum_write_word( ptr, libspectrum_snap_hl ( snap ) );
libspectrum_write_word( ptr, libspectrum_snap_de ( snap ) );
libspectrum_write_word( ptr, libspectrum_snap_bc ( snap ) );
libspectrum_write_word( ptr, libspectrum_snap_iy ( snap ) );
libspectrum_write_word( ptr, libspectrum_snap_ix ( snap ) );
*(*ptr)++ = libspectrum_snap_iff2( snap ) ? 0x04 : 0x00;
*(*ptr)++ = libspectrum_snap_r ( snap );
*(*ptr)++ = libspectrum_snap_f ( snap );
*(*ptr)++ = libspectrum_snap_a ( snap );
libspectrum_write_word( ptr, libspectrum_snap_sp ( snap ) );
*(*ptr)++ = libspectrum_snap_im( snap );
*(*ptr)++ = libspectrum_snap_out_ula( snap ) & 0x07;
}
static libspectrum_error
write_48k_sna( libspectrum_byte **buffer, libspectrum_byte **ptr,
size_t *length, libspectrum_snap *snap )
{
libspectrum_error error;
libspectrum_byte *stack, *sp;
/* Must have somewhere in RAM to store PC */
if( libspectrum_snap_sp( snap ) < 0x4002 ) {
libspectrum_print_error( LIBSPECTRUM_ERROR_INVALID,
"SP is too low (0x%04x) to stack PC",
libspectrum_snap_sp( snap ) );
return LIBSPECTRUM_ERROR_INVALID;
}
libspectrum_make_room( buffer, 0xc000, ptr, length );
error = write_page( &( (*ptr)[ 0x0000 ] ), snap, 5 );
if( error ) return error;
error = write_page( &( (*ptr)[ 0x4000 ] ), snap, 2 );
if( error ) return error;
error = write_page( &( (*ptr)[ 0x8000 ] ), snap, 0 );
if( error ) return error;
/* Place PC on the stack */
stack = &( (*ptr)[ libspectrum_snap_sp( snap ) - 0x4000 - 2 ] );
libspectrum_write_word( &stack, libspectrum_snap_pc( snap ) );
*ptr += 0xc000;
/* Store the new value of SP */
sp = *buffer + SNA_OFFSET_SP;
libspectrum_write_word( &sp, libspectrum_snap_sp( snap ) - 2 );
return LIBSPECTRUM_ERROR_NONE;
}
/* Routines for transferring the Z80 contents to and from snapshots */
static void
z80_from_snapshot( libspectrum_snap *snap )
{
A = libspectrum_snap_a ( snap ); F = libspectrum_snap_f ( snap );
A_ = libspectrum_snap_a_( snap ); F_ = libspectrum_snap_f_( snap );
BC = libspectrum_snap_bc ( snap ); DE = libspectrum_snap_de ( snap );
HL = libspectrum_snap_hl ( snap ); BC_ = libspectrum_snap_bc_( snap );
DE_ = libspectrum_snap_de_( snap ); HL_ = libspectrum_snap_hl_( snap );
IX = libspectrum_snap_ix( snap ); IY = libspectrum_snap_iy( snap );
I = libspectrum_snap_i ( snap ); R = R7 = libspectrum_snap_r( snap );
SP = libspectrum_snap_sp( snap ); PC = libspectrum_snap_pc( snap );
IFF1 = libspectrum_snap_iff1( snap ); IFF2 = libspectrum_snap_iff2( snap );
IM = libspectrum_snap_im( snap );
z80.halted = libspectrum_snap_halted( snap );
z80.interrupts_enabled_at =
libspectrum_snap_last_instruction_ei( snap ) ? z80_tstates : -1;
}
static int
libspectrum_sna_read_data( const libspectrum_byte *buffer,
size_t buffer_length, libspectrum_snap *snap )
{
int error, page, i;
libspectrum_word sp, offset;
if( buffer_length < 0xc000 ) {
libspectrum_print_error(
LIBSPECTRUM_ERROR_CORRUPT,
"libspectrum_sna_read_data: not enough data in buffer"
);
return LIBSPECTRUM_ERROR_CORRUPT;
}
switch( libspectrum_snap_machine( snap ) ) {
case LIBSPECTRUM_MACHINE_48:
sp = libspectrum_snap_sp( snap );
if( sp < 0x4000 || sp == 0xffff ) {
libspectrum_print_error(
LIBSPECTRUM_ERROR_CORRUPT,
"libspectrum_sna_read_data: SP invalid (0x%04x)", sp
);
return LIBSPECTRUM_ERROR_CORRUPT;
}
/* Rescue PC from the stack */
offset = sp - 0x4000;
libspectrum_snap_set_pc( snap, buffer[offset] + 0x100 * buffer[offset+1] );
/* Increase SP as PC has been unstacked */
libspectrum_snap_set_sp( snap, libspectrum_snap_sp( snap ) + 2 );
/* And split the pages up */
error = libspectrum_split_to_48k_pages( snap, buffer );
if( error != LIBSPECTRUM_ERROR_NONE ) return error;
break;
case LIBSPECTRUM_MACHINE_PENT:
for( i=0; i<8; i++ ) {
libspectrum_byte *ram = libspectrum_new( libspectrum_byte, 0x4000 );
libspectrum_snap_set_pages( snap, i, ram );
}
memcpy( libspectrum_snap_pages( snap, 5 ), &buffer[0x0000], 0x4000 );
memcpy( libspectrum_snap_pages( snap, 2 ), &buffer[0x4000], 0x4000 );
error = libspectrum_sna_read_128_header( buffer + 0xc000,
buffer_length - 0xc000, snap );
if( error != LIBSPECTRUM_ERROR_NONE ) return error;
page = libspectrum_snap_out_128_memoryport( snap ) & 0x07;
if( page == 5 || page == 2 ) {
if( memcmp( libspectrum_snap_pages( snap, page ),
&buffer[0x8000], 0x4000 ) ) {
libspectrum_print_error(
LIBSPECTRUM_ERROR_CORRUPT,
"libspectrum_sna_read_data: duplicated page not identical"
);
return LIBSPECTRUM_ERROR_CORRUPT;
}
} else {
memcpy( libspectrum_snap_pages( snap, page ), &buffer[0x8000], 0x4000 );
}
buffer += 0xc000 + LIBSPECTRUM_SNA_128_HEADER_LENGTH;
buffer_length -= 0xc000 + LIBSPECTRUM_SNA_128_HEADER_LENGTH;
error = libspectrum_sna_read_128_data( buffer, buffer_length, snap );
if( error != LIBSPECTRUM_ERROR_NONE ) return error;
break;
default:
libspectrum_print_error( LIBSPECTRUM_ERROR_LOGIC,
"libspectrum_sna_read_data: unknown machine" );
return LIBSPECTRUM_ERROR_LOGIC;
}
return LIBSPECTRUM_ERROR_NONE;
}
