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Diffstat (limited to 'lib/rbcodec/codecs/libgme/nsf_cpu.c')
-rw-r--r--lib/rbcodec/codecs/libgme/nsf_cpu.c115
1 files changed, 115 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libgme/nsf_cpu.c b/lib/rbcodec/codecs/libgme/nsf_cpu.c
new file mode 100644
index 0000000000..1f44bd3c3c
--- /dev/null
+++ b/lib/rbcodec/codecs/libgme/nsf_cpu.c
@@ -0,0 +1,115 @@
1// Normal cpu for NSF emulator
2
3// Game_Music_Emu 0.6-pre. http://www.slack.net/~ant/
4
5#include "nsf_emu.h"
6
7#include "blargg_endian.h"
8
9#ifdef BLARGG_DEBUG_H
10 //#define CPU_LOG_START 1000000
11 //#include "nes_cpu_log.h"
12 #undef LOG_MEM
13#endif
14
15/* Copyright (C) 2003-2008 Shay Green. This module is free software; you
16can redistribute it and/or modify it under the terms of the GNU Lesser
17General Public License as published by the Free Software Foundation; either
18version 2.1 of the License, or (at your option) any later version. This
19module is distributed in the hope that it will be useful, but WITHOUT ANY
20WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
21FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
22details. You should have received a copy of the GNU Lesser General Public
23License along with this module; if not, write to the Free Software Foundation,
24Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
25
26#include "blargg_source.h"
27
28#ifndef LOG_MEM
29 #define LOG_MEM( addr, str, data ) data
30#endif
31
32int read_mem( struct Nsf_Emu* this, addr_t addr )
33{
34 int result = this->low_ram [addr & (low_ram_size-1)]; // also handles wrap-around
35 if ( addr & 0xE000 )
36 {
37 result = *Cpu_get_code( &this->cpu, addr );
38 if ( addr < sram_addr )
39 {
40 if ( addr == apu_status_addr )
41 result = Apu_read_status( &this->apu, Cpu_time( &this->cpu ) );
42 else
43 result = cpu_read( this, addr );
44 }
45 }
46 return LOG_MEM( addr, ">", result );
47}
48
49void write_mem( struct Nsf_Emu* this, addr_t addr, int data )
50{
51 (void) LOG_MEM( addr, "<", data );
52
53 int offset = addr - sram_addr;
54 if ( (unsigned) offset < sram_size )
55 {
56 sram( this ) [offset] = data;
57 }
58 else
59 {
60 // after sram because cpu handles most low_ram accesses internally already
61 int temp = addr & (low_ram_size-1); // also handles wrap-around
62 if ( !(addr & 0xE000) )
63 {
64 this->low_ram [temp] = data;
65 }
66 else
67 {
68 int bank = addr - banks_addr;
69 if ( (unsigned) bank < bank_count )
70 {
71 write_bank( this, bank, data );
72 }
73 else if ( (unsigned) (addr - apu_io_addr) < apu_io_size )
74 {
75 Apu_write_register( &this->apu, Cpu_time( &this->cpu ), addr, data );
76 }
77 else
78 {
79 #ifndef NSF_EMU_APU_ONLY
80 // 0x8000-0xDFFF is writable
81 int i = addr - 0x8000;
82 if ( fds_enabled( this ) && (unsigned) i < fdsram_size )
83 fdsram( this ) [i] = data;
84 else
85 #endif
86 cpu_write( this, addr, data );
87 }
88 }
89 }
90}
91
92#define READ_LOW( addr ) (LOG_MEM( addr, ">", this->low_ram [addr] ))
93#define WRITE_LOW( addr, data ) (LOG_MEM( addr, "<", this->low_ram [addr] = data ))
94
95#define CAN_WRITE_FAST( addr ) (addr < low_ram_size)
96#define WRITE_FAST WRITE_LOW
97
98// addr < 0x2000 || addr >= 0x8000
99#define CAN_READ_FAST( addr ) ((addr ^ 0x8000) < 0xA000)
100#define READ_FAST( addr, out ) (LOG_MEM( addr, ">", out = READ_CODE( addr ) ))
101
102#define READ_MEM( addr ) read_mem( this, addr )
103#define WRITE_MEM( addr, data ) write_mem( this, addr, data )
104
105#define CPU_BEGIN \
106bool run_cpu_until( struct Nsf_Emu* this, nes_time_t end ) \
107{ \
108 struct Nes_Cpu* cpu = &this->cpu; \
109 Cpu_set_end_time( cpu, end ); \
110 if ( *Cpu_get_code( cpu, cpu->r.pc ) != halt_opcode ) \
111 {
112 #include "nes_cpu_run.h"
113 }
114 return Cpu_time_past_end( cpu ) < 0;
115}