diff options
Diffstat (limited to 'apps/codecs/libgme/nes_cpu.c')
-rw-r--r-- | apps/codecs/libgme/nes_cpu.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/apps/codecs/libgme/nes_cpu.c b/apps/codecs/libgme/nes_cpu.c new file mode 100644 index 0000000000..d255cf5485 --- /dev/null +++ b/apps/codecs/libgme/nes_cpu.c | |||
@@ -0,0 +1,62 @@ | |||
1 | // Game_Music_Emu 0.6-pre. http://www.slack.net/~ant/ | ||
2 | |||
3 | #include "nes_cpu.h" | ||
4 | |||
5 | #include "blargg_endian.h" | ||
6 | |||
7 | /* Copyright (C) 2003-2008 Shay Green. This module is free software; you | ||
8 | can redistribute it and/or modify it under the terms of the GNU Lesser | ||
9 | General Public License as published by the Free Software Foundation; either | ||
10 | version 2.1 of the License, or (at your option) any later version. This | ||
11 | module is distributed in the hope that it will be useful, but WITHOUT ANY | ||
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | ||
13 | FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more | ||
14 | details. You should have received a copy of the GNU Lesser General Public | ||
15 | License along with this module; if not, write to the Free Software Foundation, | ||
16 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ | ||
17 | |||
18 | #include "blargg_source.h" | ||
19 | |||
20 | inline void set_code_page( struct Nes_Cpu* this, int i, void const* p ) | ||
21 | { | ||
22 | byte const* p2 = STATIC_CAST(byte const*,p) - NES_CPU_OFFSET( i * page_size ); | ||
23 | this->cpu_state->code_map [i] = p2; | ||
24 | this->cpu_state_.code_map [i] = p2; | ||
25 | } | ||
26 | |||
27 | void Cpu_map_code( struct Nes_Cpu* this, addr_t start, int size, void const* data, int mirror_size ) | ||
28 | { | ||
29 | // address range must begin and end on page boundaries | ||
30 | require( start % page_size == 0 ); | ||
31 | require( size % page_size == 0 ); | ||
32 | require( start + size <= 0x10000 ); | ||
33 | require( mirror_size % page_size == 0 ); | ||
34 | |||
35 | int offset; | ||
36 | for ( offset = 0; offset < size; offset += page_size ) | ||
37 | set_code_page( this, NES_CPU_PAGE( start + offset ), | ||
38 | STATIC_CAST(char const*,data) + (offset & ((unsigned) mirror_size - 1)) ); | ||
39 | } | ||
40 | |||
41 | void Cpu_reset( struct Nes_Cpu* this, void const* unmapped_page ) | ||
42 | { | ||
43 | check( this->cpu_state == &this->cpu_state_ ); | ||
44 | this->cpu_state = &this->cpu_state_; | ||
45 | |||
46 | this->r.flags = irq_inhibit_mask; | ||
47 | this->r.sp = 0xFF; | ||
48 | this->r.pc = 0; | ||
49 | this->r.a = 0; | ||
50 | this->r.x = 0; | ||
51 | this->r.y = 0; | ||
52 | |||
53 | this->cpu_state_.time = 0; | ||
54 | this->cpu_state_.base = 0; | ||
55 | this->irq_time = future_time; | ||
56 | this->end_time = future_time; | ||
57 | |||
58 | set_code_page( this, page_count, unmapped_page ); | ||
59 | Cpu_map_code( this, 0, 0x10000, unmapped_page, page_size ); | ||
60 | |||
61 | blargg_verify_byte_order(); | ||
62 | } | ||