enenv.h

简单的虚拟机

/* memory available: 1M bytes */
#include <stdbool.h>

#define AVAILMEM	0xFFFFF
#define SIGNATURE	0x5A4D

typedef char byte;
typedef unsigned short word;
typedef unsigned int dword;

#define FLAG_C 0x0001
#define FLAG_P 0x0004
#define FLAG_A 0x0010
#define FLAG_Z 0x0040
#define FLAG_S 0x0080
#define FLAG_T 0x0100
#define FLAG_I 0x0200
#define FLAG_D 0x0400
#define FLAG_O 0x0800

struct general_reg
{
	word	ax;
	word	cx;
	word	dx;
	word	bx;
	word	sp;
	word	bp;
	word	si;
	word	di;
};

struct segment_reg
{
	word	es;
	word	cs;
	word	ss;
	word	ds;
	word	fs;
	word	gs;
};

struct CPU
{
	struct general_reg greg;
	struct segment_reg sreg;
	word	ip;
	int	flags;
	bool	status;
	byte*	ram;
};

#define greg16_addr(index) ((word*)(&cpu.greg)+(index))
#define greg8_addr(index) ((byte*)(&cpu.greg)+((index&4)?((index&3)*2+1):(index*2)))
#define sreg_addr(index) ((word*)(&cpu.sreg)+(index))

/*
   struct PSP
   {
   word	int20;
   word	memavail;
   dword	int22;
   dword	int23;
   dword	int24;
   word	env;
   word	int21;
   byte	retf;
   byte	fmtcmd1[16];
   byte	fmtcmd2[16];
   byte	cmdlen;
   byte	unfmtcmd[127];
   }; */

struct CPU cpu;