rockbox/lib/rbcodec/codecs/libgme/nes_cpu.c
Sean Bartell f40bfc9267 Add codecs to librbcodec.
Change-Id: Id7f4717d51ed02d67cb9f9cb3c0ada4a81843f97
Reviewed-on: http://gerrit.rockbox.org/137
Reviewed-by: Nils Wallménius <nils@rockbox.org>
Tested-by: Nils Wallménius <nils@rockbox.org>
2012-04-25 22:13:20 +02:00

62 lines
2.1 KiB
C

// Game_Music_Emu 0.6-pre. http://www.slack.net/~ant/
#include "nes_cpu.h"
#include "blargg_endian.h"
/* Copyright (C) 2003-2008 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"
static inline void set_code_page( struct Nes_Cpu* this, int i, void const* p )
{
byte const* p2 = STATIC_CAST(byte const*,p) - NES_CPU_OFFSET( i * page_size );
this->cpu_state->code_map [i] = p2;
this->cpu_state_.code_map [i] = p2;
}
void Cpu_map_code( struct Nes_Cpu* this, addr_t start, int size, void const* data, int mirror_size )
{
// address range must begin and end on page boundaries
require( start % page_size == 0 );
require( size % page_size == 0 );
require( start + size <= 0x10000 );
require( mirror_size % page_size == 0 );
int offset;
for ( offset = 0; offset < size; offset += page_size )
set_code_page( this, NES_CPU_PAGE( start + offset ),
STATIC_CAST(char const*,data) + (offset & ((unsigned) mirror_size - 1)) );
}
void Cpu_reset( struct Nes_Cpu* this, void const* unmapped_page )
{
check( this->cpu_state == &this->cpu_state_ );
this->cpu_state = &this->cpu_state_;
this->r.flags = irq_inhibit_mask;
this->r.sp = 0xFF;
this->r.pc = 0;
this->r.a = 0;
this->r.x = 0;
this->r.y = 0;
this->cpu_state_.time = 0;
this->cpu_state_.base = 0;
this->irq_time = future_time;
this->end_time = future_time;
set_code_page( this, page_count, unmapped_page );
Cpu_map_code( this, 0, 0x10000, unmapped_page, page_size );
blargg_verify_byte_order();
}