1 files changed, 85 insertions, 0 deletions

diff --git a/lib/rbcodec/codecs/libgme/z80_cpu.c b/lib/rbcodec/codecs/libgme/z80_cpu.c
new file mode 100644
index 0000000000..a31236020e
--- /dev/null
+++ b/lib/rbcodec/codecs/libgme/z80_cpu.c
@@ -0,0 +1,85 @@
+// Game_Music_Emu 0.6-pre. http://www.slack.net/~ant/
+
+#include "z80_cpu.h"
+
+/* Copyright (C) 2006-2008 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"
+
+// flags, named with hex value for clarity
+int const S80 = 0x80;
+int const Z40 = 0x40;
+int const F20 = 0x20;
+int const H10 = 0x10;
+int const F08 = 0x08;
+int const V04 = 0x04;
+int const P04 = 0x04;
+int const N02 = 0x02;
+int const C01 = 0x01;
+
+void Z80_init( struct Z80_Cpu* this ) 
+{
+        this->cpu_state = &this->cpu_state_;
+        
+        int i;
+        for ( i = 0x100; --i >= 0; )
+        {
+                int p, even = 1;
+                for ( p = i; p; p >>= 1 )
+                        even ^= p;
+                int n = (i & (S80 | F20 | F08)) | ((even & 1) * P04);
+                this->szpc [i] = n;
+                this->szpc [i + 0x100] = n | C01;
+        }
+        this->szpc [0x000] |= Z40;
+        this->szpc [0x100] |= Z40;
+}
+
+static inline void set_page( struct Z80_Cpu* this, int i, void* write, void const* read )
+{
+        int offset = Z80_CPU_OFFSET( i * page_size );
+        byte      * write2 = STATIC_CAST(byte      *,write) - offset;
+        byte const* read2  = STATIC_CAST(byte const*,read ) - offset;
+        this->cpu_state_.write [i] = write2;
+        this->cpu_state_.read  [i] = read2;
+        this->cpu_state->write [i] = write2;
+        this->cpu_state->read  [i] = read2;
+}
+
+void Z80_reset( struct Z80_Cpu* this, void* unmapped_write, void const* unmapped_read )
+{
+        check( this->cpu_state == &this->cpu_state_ );
+        this->cpu_state = &this->cpu_state_;
+        this->cpu_state_.time = 0;
+        this->cpu_state_.base = 0;
+        this->end_time_   = 0;
+        
+        int i;
+        for ( i = 0; i < page_count + 1; i++ )
+                set_page( this, i, unmapped_write, unmapped_read );
+        
+        memset( &this->r, 0, sizeof this->r );
+}
+
+void Z80_map_mem( struct Z80_Cpu* this, addr_t start, int size, void* write, void const* read )
+{
+        // address range must begin and end on page boundaries
+        require( start % page_size == 0 );
+        require( size  % page_size == 0 );
+        require( start + size <= 0x10000 );
+        
+        int offset;
+        for ( offset = 0; offset < size; offset += page_size )
+                set_page( this, (start + offset) >> page_bits,
+                                STATIC_CAST(char      *,write) + offset,
+                                STATIC_CAST(char const*,read ) + offset );
+}