1 files changed, 95 insertions, 0 deletions

diff --git a/apps/codecs/libgme/hes_cpu.h b/apps/codecs/libgme/hes_cpu.h
new file mode 100644
index 0000000000..f3bcf7d4cf
--- /dev/null
+++ b/apps/codecs/libgme/hes_cpu.h
@@ -0,0 +1,95 @@
+// PC Engine CPU emulator for use with HES music files
+
+// Game_Music_Emu 0.5.2
+#ifndef HES_CPU_H
+#define HES_CPU_H
+
+#include "blargg_common.h"
+
+typedef blargg_long hes_time_t; // clock cycle count
+typedef unsigned hes_addr_t; // 16-bit address
+
+struct Hes_Emu;
+
+enum { future_hes_time = LONG_MAX / 2 + 1 };
+enum { page_size = 0x2000 };
+enum { page_shift = 13 };
+enum { page_count = 8 };
+
+// Attempt to execute instruction here results in CPU advancing time to
+// lesser of irq_time() and end_time() (or end_time() if IRQs are
+// disabled)
+enum { idle_addr = 0x1FFF };
+        
+// Can read this many bytes past end of a page
+enum { cpu_padding = 8 };
+enum { irq_inhibit = 0x04 };
+
+
+// Cpu state
+struct state_t {
+        uint8_t const* code_map [page_count + 1];
+        hes_time_t base;
+        blargg_long time;
+};
+
+// Cpu registers
+struct registers_t {
+        uint16_t pc;
+        uint8_t a;
+        uint8_t x;
+        uint8_t y;
+        uint8_t status;
+        uint8_t sp;
+};
+
+struct Hes_Cpu {
+        struct registers_t r;
+
+        hes_time_t irq_time;
+        hes_time_t end_time;
+        
+        struct state_t* state; // points to state_ or a local copy within run()
+        struct state_t state_;
+        
+        // page mapping registers
+        uint8_t mmr [page_count + 1];
+        uint8_t ram [page_size];
+};
+
+// Init cpu state
+void Cpu_init( struct Hes_Cpu* this );
+
+// Reset hes cpu
+void Cpu_reset( struct Hes_Cpu* this );
+
+// Set end_time and run CPU from current time. Returns true if any illegal
+// instructions were encountered.
+bool Cpu_run( struct Hes_Emu* this, hes_time_t end_time ) ICODE_ATTR;
+
+void Cpu_set_mmr( struct Hes_Emu* this, int reg, int bank ) ICODE_ATTR;
+
+// Time of ning of next instruction to be executed
+static inline hes_time_t Cpu_time( struct Hes_Cpu* this )
+{
+        return this->state->time + this->state->base;
+}
+
+static inline uint8_t const* Cpu_get_code( struct Hes_Cpu* this, hes_addr_t addr )
+{
+        return this->state->code_map [addr >> page_shift] + addr
+        #if !defined (BLARGG_NONPORTABLE)
+                % (unsigned) page_size
+        #endif
+        ;
+}
+
+static inline int Cpu_update_end_time( struct Hes_Cpu* this, uint8_t reg_status, hes_time_t t, hes_time_t irq )
+{
+        if ( irq < t && !(reg_status & irq_inhibit) ) t = irq;
+        int delta = this->state->base - t;
+        this->state->base = t;
+        return delta;
+}
+
+#endif