f40bfc9267
Change-Id: Id7f4717d51ed02d67cb9f9cb3c0ada4a81843f97 Reviewed-on: http://gerrit.rockbox.org/137 Reviewed-by: Nils Wallménius <nils@rockbox.org> Tested-by: Nils Wallménius <nils@rockbox.org>
116 lines
2.9 KiB
C
116 lines
2.9 KiB
C
// Z80 CPU emulator
|
|
|
|
// Game_Music_Emu 0.6-pre
|
|
#ifndef Z80_CPU_H
|
|
#define Z80_CPU_H
|
|
|
|
#include "blargg_source.h"
|
|
#include "blargg_endian.h"
|
|
|
|
typedef int cpu_time_t;
|
|
typedef int addr_t;
|
|
|
|
enum { page_bits = 10 };
|
|
enum { page_size = 1 << page_bits };
|
|
enum { page_count = 0x10000 / page_size };
|
|
|
|
// Can read this far past end of memory
|
|
enum { cpu_padding = 0x100 };
|
|
|
|
// Can read this many bytes past end of a page
|
|
enum { page_padding = 4 };
|
|
|
|
#ifdef BLARGG_BIG_ENDIAN
|
|
struct regs_t { byte b,c, d,e, h,l, flags,a; };
|
|
#else
|
|
struct regs_t { byte c,b, e,d, l,h, a,flags; };
|
|
#endif
|
|
// BOOST_STATIC_ASSERT( sizeof (regs_t) == 8 );
|
|
|
|
struct pairs_t { uint16_t bc, de, hl, fa; };
|
|
|
|
// Registers are not updated until run() returns
|
|
struct registers_t {
|
|
uint16_t pc;
|
|
uint16_t sp;
|
|
uint16_t ix;
|
|
uint16_t iy;
|
|
union {
|
|
struct regs_t b; // b.b, b.c, b.d, b.e, b.h, b.l, b.flags, b.a
|
|
struct pairs_t w; // w.bc, w.de, w.hl. w.fa
|
|
};
|
|
union {
|
|
struct regs_t b;
|
|
struct pairs_t w;
|
|
} alt;
|
|
byte iff1;
|
|
byte iff2;
|
|
byte r;
|
|
byte i;
|
|
byte im;
|
|
};
|
|
|
|
struct cpu_state_t {
|
|
byte const* read [page_count + 1];
|
|
byte * write [page_count + 1];
|
|
cpu_time_t base;
|
|
cpu_time_t time;
|
|
};
|
|
|
|
struct Z80_Cpu {
|
|
byte szpc [0x200];
|
|
cpu_time_t end_time_;
|
|
|
|
struct cpu_state_t* cpu_state; // points to cpu_state_ or a local copy within run()
|
|
struct cpu_state_t cpu_state_;
|
|
|
|
struct registers_t r;
|
|
};
|
|
|
|
void Z80_init( struct Z80_Cpu* this );
|
|
|
|
// Clears registers and maps all pages to unmapped
|
|
void Z80_reset( struct Z80_Cpu* this, void* unmapped_write, void const* unmapped_read );
|
|
|
|
// TODO: split mapping out of CPU
|
|
|
|
// Maps memory. Start and size must be multiple of page_size.
|
|
void Z80_map_mem( struct Z80_Cpu* this, addr_t addr, int size, void* write, void const* read );
|
|
|
|
// Time of beginning of next instruction
|
|
static inline cpu_time_t Z80_time( struct Z80_Cpu* this ) { return this->cpu_state->time + this->cpu_state->base; }
|
|
|
|
// Alter current time
|
|
static inline void Z80_set_time( struct Z80_Cpu* this, cpu_time_t t ) { this->cpu_state->time = t - this->cpu_state->base; }
|
|
static inline void Z80_adjust_time( struct Z80_Cpu* this, int delta ) { this->cpu_state->time += delta; }
|
|
|
|
#ifdef BLARGG_NONPORTABLE
|
|
#define Z80_CPU_OFFSET( addr ) (addr)
|
|
#else
|
|
#define Z80_CPU_OFFSET( addr ) ((addr) & (page_size - 1))
|
|
#endif
|
|
|
|
// Maps address to pointer to that byte
|
|
static inline byte* Z80_write( struct Z80_Cpu* this, addr_t addr )
|
|
{
|
|
return this->cpu_state->write [(unsigned) addr >> page_bits] + Z80_CPU_OFFSET( addr );
|
|
}
|
|
|
|
static inline byte const* Z80_read( struct Z80_Cpu* this, addr_t addr )
|
|
{
|
|
return this->cpu_state->read [(unsigned) addr >> page_bits] + Z80_CPU_OFFSET( addr );
|
|
}
|
|
|
|
static inline void Z80_map_mem_rw( struct Z80_Cpu* this, addr_t addr, int size, void* p )
|
|
{
|
|
Z80_map_mem( this, addr, size, p, p );
|
|
}
|
|
|
|
static inline void Z80_set_end_time( struct Z80_Cpu* this, cpu_time_t t )
|
|
{
|
|
cpu_time_t delta = this->cpu_state->base - t;
|
|
this->cpu_state->base = t;
|
|
this->cpu_state->time += delta;
|
|
}
|
|
|
|
#endif
|