rockbox/apps/codecs/libgme/gbs_cpu.c
Andree Buschmann 13cbade08a Update libgme to Blargg's Game_Music_Emu 0.6-pre.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30397 a1c6a512-1295-4272-9138-f99709370657
2011-08-31 19:19:49 +00:00

120 lines
3.6 KiB
C

// Game_Music_Emu 0.6-pre. http://www.slack.net/~ant/
#include "gbs_emu.h"
#include "blargg_endian.h"
/* Copyright (C) 2003-2009 Shay Green. This module is free software; you
can redistribute it and/or modify it under the terms of the GNU Lesser
General Public License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. This
module is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
details. You should have received a copy of the GNU Lesser General Public
License along with this module; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
#include "blargg_source.h"
#ifndef LOG_MEM
#define LOG_MEM( addr, str, data ) data
#endif
int read_mem( struct Gbs_Emu* this, addr_t addr )
{
int result = *Cpu_get_code( &this->cpu, addr );
if ( (unsigned) (addr - io_addr) < io_size )
result = Apu_read_register( &this->apu, Time( this ), addr );
return LOG_MEM( addr, ">", result );
}
static inline void write_io_inline( struct Gbs_Emu* this, int offset, int data, int base )
{
if ( (unsigned) (offset - (io_addr - base)) < io_size )
Apu_write_register( &this->apu, Time( this ), offset + base, data & 0xFF );
else if ( (unsigned) (offset - (0xFF06 - base)) < 2 )
update_timer( this );
else if ( offset == io_base - base )
this->ram [base - ram_addr + offset] = 0; // keep joypad return value 0
else
this->ram [base - ram_addr + offset] = 0xFF;
}
void write_mem( struct Gbs_Emu* this, addr_t addr, int data )
{
(void) LOG_MEM( addr, "<", data );
int offset = addr - ram_addr;
if ( (unsigned) offset < 0x10000 - ram_addr )
{
this->ram [offset] = data;
offset -= 0xE000 - ram_addr;
if ( (unsigned) offset < 0x1F80 )
write_io_inline( this, offset, data, 0xE000 );
}
else if ( (unsigned) (offset - (0x2000 - ram_addr)) < 0x2000 )
{
set_bank( this, data & 0xFF );
}
#ifndef NDEBUG
else if ( unsigned (addr - 0x8000) < 0x2000 || unsigned (addr - 0xE000) < 0x1F00 )
{
/* dprintf( "Unmapped write $%04X\n", (unsigned) addr ); */
}
#endif
}
static void write_io_( struct Gbs_Emu* this, int offset, int data )
{
write_io_inline( this, offset, data, io_base );
}
static inline void write_io( struct Gbs_Emu* this, int offset, int data )
{
(void) LOG_MEM( offset + io_base, "<", data );
this->ram [io_base - ram_addr + offset] = data;
if ( (unsigned) offset < 0x80 )
write_io_( this, offset, data );
}
static int read_io( struct Gbs_Emu* this, int offset )
{
int const io_base = 0xFF00;
int result = this->ram [io_base - ram_addr + offset];
if ( (unsigned) (offset - (io_addr - io_base)) < io_size )
{
result = Apu_read_register( &this->apu, Time( this ), offset + io_base );
(void) LOG_MEM( offset + io_base, ">", result );
}
else
{
check( result == read_mem( offset + io_base ) );
}
return result;
}
#define READ_FAST( emu, addr, out ) \
{\
out = READ_CODE( addr );\
if ( (unsigned) (addr - io_addr) < io_size )\
out = LOG_MEM( addr, ">", Apu_read_register( &emu->apu, TIME() + emu->end_time, addr ) );\
else\
check( out == Read_mem( emu, addr ) );\
}
#define READ_MEM( emu, addr ) read_mem( emu, addr )
#define WRITE_MEM( emu, addr, data ) write_mem( emu, addr, data )
#define WRITE_IO( emu, addr, data ) write_io( emu, addr, data )
#define READ_IO( emu, addr, out ) out = read_io( emu, addr )
#define CPU_BEGIN \
void run_cpu( struct Gbs_Emu* this )\
{ \
struct Gb_Cpu* cpu = &this->cpu;
#include "gb_cpu_run.h"
}