static libspectrum_error
write_128k_sna( libspectrum_byte **buffer, libspectrum_byte **ptr,
size_t *length, libspectrum_snap *snap )
{
size_t i, page; libspectrum_error error;
page = libspectrum_snap_out_128_memoryport( snap ) & 0x07;
libspectrum_make_room( buffer, 0xc000 + LIBSPECTRUM_SNA_128_HEADER_LENGTH,
ptr, length );
error = write_page( *ptr, snap, 5 ); (*ptr) += 0x4000;
if( error ) return error;
error = write_page( *ptr, snap, 2 ); (*ptr) += 0x4000;
if( error ) return error;
error = write_page( *ptr, snap, page ); (*ptr) += 0x4000;
if( error ) return error;
libspectrum_write_word( ptr, libspectrum_snap_pc( snap ) );
*(*ptr)++ = libspectrum_snap_out_128_memoryport( snap );
*(*ptr)++ = '\0';
for( i = 0; i < 8; i++ ) {
/* Already written pages 5, 2 and whatever's paged in */
if( i == 5 || i == 2 || i == page ) continue;
libspectrum_make_room( buffer, 0x4000, ptr, length );
error = write_page( *ptr, snap, i ); (*ptr) += 0x4000;
if( error ) return error;
}
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 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;
}