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Diffstat (limited to 'gme/Kss_Cpu.h')
-rw-r--r-- | gme/Kss_Cpu.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/gme/Kss_Cpu.h b/gme/Kss_Cpu.h new file mode 100644 index 00000000..6297d100 --- /dev/null +++ b/gme/Kss_Cpu.h @@ -0,0 +1,124 @@ +// Z80 CPU emulator + +// Game_Music_Emu 0.5.2 +#ifndef KSS_CPU_H +#define KSS_CPU_H + +#include "blargg_endian.h" + +typedef blargg_long cpu_time_t; + +// must be defined by caller +void kss_cpu_out( class Kss_Cpu*, cpu_time_t, unsigned addr, int data ); +int kss_cpu_in( class Kss_Cpu*, cpu_time_t, unsigned addr ); +void kss_cpu_write( class Kss_Cpu*, unsigned addr, int data ); + +class Kss_Cpu { +public: + typedef BOOST::uint8_t uint8_t; + + // Clear registers and map all pages to unmapped + void reset( void* unmapped_write, void const* unmapped_read ); + + // Map memory. Start and size must be multiple of page_size. + enum { page_size = 0x2000 }; + void map_mem( unsigned addr, blargg_ulong size, void* write, void const* read ); + + // Map address to page + uint8_t* write( unsigned addr ); + uint8_t const* read( unsigned addr ); + + // Run until specified time is reached. Returns true if suspicious/unsupported + // instruction was encountered at any point during run. + bool run( cpu_time_t end_time ); + + // Time of beginning of next instruction + cpu_time_t time() const { return state->time + state->base; } + + // Alter current time. Not supported during run() call. + void set_time( cpu_time_t t ) { state->time = t - state->base; } + void adjust_time( int delta ) { state->time += delta; } + + typedef BOOST::uint16_t uint16_t; + + #if BLARGG_BIG_ENDIAN + struct regs_t { uint8_t b, c, d, e, h, l, flags, a; }; + #else + struct regs_t { uint8_t 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 { + regs_t b; // b.b, b.c, b.d, b.e, b.h, b.l, b.flags, b.a + pairs_t w; // w.bc, w.de, w.hl. w.fa + }; + union { + regs_t b; + pairs_t w; + } alt; + uint8_t iff1; + uint8_t iff2; + uint8_t r; + uint8_t i; + uint8_t im; + }; + //registers_t r; (below for efficiency) + + enum { idle_addr = 0xFFFF }; + + // can read this far past end of a page + enum { cpu_padding = 0x100 }; + +public: + Kss_Cpu(); + enum { page_shift = 13 }; + enum { page_count = 0x10000 >> page_shift }; +private: + uint8_t szpc [0x200]; + cpu_time_t end_time_; + struct state_t { + uint8_t const* read [page_count + 1]; + uint8_t * write [page_count + 1]; + cpu_time_t base; + cpu_time_t time; + }; + state_t* state; // points to state_ or a local copy within run() + state_t state_; + void set_end_time( cpu_time_t t ); + void set_page( int i, void* write, void const* read ); +public: + registers_t r; +}; + +#if BLARGG_NONPORTABLE + #define KSS_CPU_PAGE_OFFSET( addr ) (addr) +#else + #define KSS_CPU_PAGE_OFFSET( addr ) ((addr) & (page_size - 1)) +#endif + +inline BOOST::uint8_t* Kss_Cpu::write( unsigned addr ) +{ + return state->write [addr >> page_shift] + KSS_CPU_PAGE_OFFSET( addr ); +} + +inline BOOST::uint8_t const* Kss_Cpu::read( unsigned addr ) +{ + return state->read [addr >> page_shift] + KSS_CPU_PAGE_OFFSET( addr ); +} + +inline void Kss_Cpu::set_end_time( cpu_time_t t ) +{ + cpu_time_t delta = state->base - t; + state->base = t; + state->time += delta; +} + +#endif |