/*
 * i386 virtual CPU header
 * 
 *  Copyright (c) 2003 Fabrice Bellard
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#ifndef CPU_I386_H
#define CPU_I386_H

#include "config.h"
#include <setjmp.h>

#define R_EAX 0
#define R_ECX 1
#define R_EDX 2
#define R_EBX 3
#define R_ESP 4
#define R_EBP 5
#define R_ESI 6
#define R_EDI 7

#define R_AL 0
#define R_CL 1
#define R_DL 2
#define R_BL 3
#define R_AH 4
#define R_CH 5
#define R_DH 6
#define R_BH 7

#define R_ES 0
#define R_CS 1
#define R_SS 2
#define R_DS 3
#define R_FS 4
#define R_GS 5

/* segment descriptor fields */
#define DESC_G_MASK     (1 << 23)
#define DESC_B_MASK     (1 << 22)
#define DESC_AVL_MASK   (1 << 20)
#define DESC_P_MASK     (1 << 15)
#define DESC_DPL_SHIFT  13
#define DESC_S_MASK     (1 << 12)
#define DESC_TYPE_SHIFT 8
#define DESC_A_MASK     (1 << 8)

#define DESC_CS_MASK    (1 << 11)
#define DESC_C_MASK     (1 << 10)
#define DESC_R_MASK     (1 << 9)

#define DESC_E_MASK     (1 << 10)
#define DESC_W_MASK     (1 << 9)

/* eflags masks */
#define CC_C   	0x0001
#define CC_P 	0x0004
#define CC_A	0x0010
#define CC_Z	0x0040
#define CC_S    0x0080
#define CC_O    0x0800

#define TF_MASK 		0x00000100
#define IF_MASK 		0x00000200
#define DF_MASK 		0x00000400
#define IOPL_MASK		0x00003000
#define NT_MASK	         	0x00004000
#define RF_MASK			0x00010000
#define VM_MASK			0x00020000
#define AC_MASK			0x00040000 
#define VIF_MASK                0x00080000
#define VIP_MASK                0x00100000
#define ID_MASK                 0x00200000

#define EXCP00_DIVZ	0
#define EXCP01_SSTP	1
#define EXCP02_NMI	2
#define EXCP03_INT3	3
#define EXCP04_INTO	4
#define EXCP05_BOUND	5
#define EXCP06_ILLOP	6
#define EXCP07_PREX	7
#define EXCP08_DBLE	8
#define EXCP09_XERR	9
#define EXCP0A_TSS	10
#define EXCP0B_NOSEG	11
#define EXCP0C_STACK	12
#define EXCP0D_GPF	13
#define EXCP0E_PAGE	14
#define EXCP10_COPR	16
#define EXCP11_ALGN	17
#define EXCP12_MCHK	18

#define EXCP_INTERRUPT 	256 /* async interruption */

enum {
    CC_OP_DYNAMIC, /* must use dynamic code to get cc_op */
    CC_OP_EFLAGS,  /* all cc are explicitely computed, CC_SRC = flags */
    CC_OP_MUL, /* modify all flags, C, O = (CC_SRC != 0) */

    CC_OP_ADDB, /* modify all flags, CC_DST = res, CC_SRC = src1 */
    CC_OP_ADDW,
    CC_OP_ADDL,

    CC_OP_ADCB, /* modify all flags, CC_DST = res, CC_SRC = src1 */
    CC_OP_ADCW,
    CC_OP_ADCL,

    CC_OP_SUBB, /* modify all flags, CC_DST = res, CC_SRC = src1 */
    CC_OP_SUBW,
    CC_OP_SUBL,

    CC_OP_SBBB, /* modify all flags, CC_DST = res, CC_SRC = src1 */
    CC_OP_SBBW,
    CC_OP_SBBL,

    CC_OP_LOGICB, /* modify all flags, CC_DST = res */
    CC_OP_LOGICW,
    CC_OP_LOGICL,

    CC_OP_INCB, /* modify all flags except, CC_DST = res, CC_SRC = C */
    CC_OP_INCW,
    CC_OP_INCL,

    CC_OP_DECB, /* modify all flags except, CC_DST = res, CC_SRC = C  */
    CC_OP_DECW,
    CC_OP_DECL,

    CC_OP_SHLB, /* modify all flags, CC_DST = res, CC_SRC.lsb = C */
    CC_OP_SHLW,
    CC_OP_SHLL,

    CC_OP_SARB, /* modify all flags, CC_DST = res, CC_SRC.lsb = C */
    CC_OP_SARW,
    CC_OP_SARL,

    CC_OP_NB,
};

#ifdef __i386__
#define USE_X86LDOUBLE
#endif

#ifdef USE_X86LDOUBLE
typedef long double CPU86_LDouble;
#else
typedef double CPU86_LDouble;
#endif

typedef struct SegmentCache {
    uint8_t *base;
    unsigned long limit;
    uint8_t seg_32bit;
} SegmentCache;

typedef struct SegmentDescriptorTable {
    uint8_t *base;
    unsigned long limit;
    /* this is the returned base when reading the register, just to
    avoid that the emulated program modifies it */
    unsigned long emu_base;
} SegmentDescriptorTable;

typedef struct CPUX86State {
    /* standard registers */
    uint32_t regs[8];
    uint32_t eip;
    uint32_t eflags; /* eflags register. During CPU emulation, CC
                        flags and DF are set to zero because they are
                        stored elsewhere */

    /* emulator internal eflags handling */
    uint32_t cc_src;
    uint32_t cc_dst;
    uint32_t cc_op;
    int32_t df; /* D flag : 1 if D = 0, -1 if D = 1 */

    /* FPU state */
    unsigned int fpstt; /* top of stack index */
    unsigned int fpus;
    unsigned int fpuc;
    uint8_t fptags[8];   /* 0 = valid, 1 = empty */
    CPU86_LDouble fpregs[8];    

    /* emulator internal variables */
    CPU86_LDouble ft0;
    union {
	float f;
        double d;
	int i32;
        int64_t i64;
    } fp_convert;
    
    /* segments */
    uint32_t segs[6]; /* selector values */
    SegmentCache seg_cache[6]; /* info taken from LDT/GDT */
    SegmentDescriptorTable gdt;
    SegmentDescriptorTable ldt;
    SegmentDescriptorTable idt;
    
    /* exception/interrupt handling */
    jmp_buf jmp_env;
    int exception_index;
    int error_code;
    uint32_t cr2;
    int interrupt_request;

    /* user data */
    void *opaque;
} CPUX86State;

/* all CPU memory access use these macros */
static inline int ldub(void *ptr)
{
    return *(uint8_t *)ptr;
}

static inline int ldsb(void *ptr)
{
    return *(int8_t *)ptr;
}

static inline void stb(void *ptr, int v)
{
    *(uint8_t *)ptr = v;
}

/* NOTE: on arm, putting 2 in /proc/sys/debug/alignment so that the
   kernel handles unaligned load/stores may give better results, but
   it is a system wide setting : bad */
#if defined(WORDS_BIGENDIAN) || defined(__arm__)

/* conservative code for little endian unaligned accesses */
static inline int lduw(void *ptr)
{
#ifdef __powerpc__
    int val;
    __asm__ __volatile__ ("lhbrx %0,0,%1" : "=r" (val) : "r" (ptr));
    return val;
#else
    uint8_t *p = ptr;
    return p[0] | (p[1] << 8);
#endif
}

static inline int ldsw(void *ptr)
{
#ifdef __powerpc__
    int val;
    __asm__ __volatile__ ("lhbrx %0,0,%1" : "=r" (val) : "r" (ptr));
    return (int16_t)val;
#else
    uint8_t *p = ptr;
    return (int16_t)(p[0] | (p[1] << 8));
#endif
}

static inline int ldl(void *ptr)
{
#ifdef __powerpc__
    int val;
    __asm__ __volatile__ ("lwbrx %0,0,%1" : "=r" (val) : "r" (ptr));
    return val;
#else
    uint8_t *p = ptr;
    return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
#endif
}

static inline uint64_t ldq(void *ptr)
{
    uint8_t *p = ptr;
    uint32_t v1, v2;
    v1 = ldl(p);
    v2 = ldl(p + 4);
    return v1 | ((uint64_t)v2 << 32);
}

static inline void stw(void *ptr, int v)
{
#ifdef __powerpc__
    __asm__ __volatile__ ("sthbrx %1,0,%2" : "=m" (*(uint16_t *)ptr) : "r" (v), "r" (ptr));
#else
    uint8_t *p = ptr;
    p[0] = v;
    p[1] = v >> 8;
#endif
}

static inline void stl(void *ptr, int v)
{
#ifdef __powerpc__
    __asm__ __volatile__ ("stwbrx %1,0,%2" : "=m" (*(uint32_t *)ptr) : "r" (v), "r" (ptr));
#else
    uint8_t *p = ptr;
    p[0] = v;
    p[1] = v >> 8;
    p[2] = v >> 16;
    p[3] = v >> 24;
#endif
}

static inline void stq(void *ptr, uint64_t v)
{
    uint8_t *p = ptr;
    stl(p, (uint32_t)v);
    stl(p + 4, v >> 32);
}

/* float access */

static inline float ldfl(void *ptr)
{
    union {
        float f;
        uint32_t i;
    } u;
    u.i = ldl(ptr);
    return u.f;
}

static inline void stfl(void *ptr, float v)
{
    union {
        float f;
        uint32_t i;
    } u;
    u.f = v;
    stl(ptr, u.i);
}

#if defined(__arm__) && !defined(WORDS_BIGENDIAN)

/* NOTE: arm is horrible as double 32 bit words are stored in big endian ! */
static inline double ldfq(void *ptr)
{
    union {
        double d;
        uint32_t tab[2];
    } u;
    u.tab[1] = ldl(ptr);
    u.tab[0] = ldl(ptr + 4);
    return u.d;
}

static inline void stfq(void *ptr, double v)
{
    union {
        double d;
        uint32_t tab[2];
    } u;
    u.d = v;
    stl(ptr, u.tab[1]);
    stl(ptr + 4, u.tab[0]);
}

#else
static inline double ldfq(void *ptr)
{
    union {
        double d;
        uint64_t i;
    } u;
    u.i = ldq(ptr);
    return u.d;
}

static inline void stfq(void *ptr, double v)
{
    union {
        double d;
        uint64_t i;
    } u;
    u.d = v;
    stq(ptr, u.i);
}
#endif

#else

static inline int lduw(void *ptr)
{
    return *(uint16_t *)ptr;
}

static inline int ldsw(void *ptr)
{
    return *(int16_t *)ptr;
}

static inline int ldl(void *ptr)
{
    return *(uint32_t *)ptr;
}

static inline uint64_t ldq(void *ptr)
{
    return *(uint64_t *)ptr;
}

static inline void stw(void *ptr, int v)
{
    *(uint16_t *)ptr = v;
}

static inline void stl(void *ptr, int v)
{
    *(uint32_t *)ptr = v;
}

static inline void stq(void *ptr, uint64_t v)
{
    *(uint64_t *)ptr = v;
}

/* float access */

static inline float ldfl(void *ptr)
{
    return *(float *)ptr;
}

static inline double ldfq(void *ptr)
{
    return *(double *)ptr;
}

static inline void stfl(void *ptr, float v)
{
    *(float *)ptr = v;
}

static inline void stfq(void *ptr, double v)
{
    *(double *)ptr = v;
}
#endif

#ifndef IN_OP_I386
void cpu_x86_outb(CPUX86State *env, int addr, int val);
void cpu_x86_outw(CPUX86State *env, int addr, int val);
void cpu_x86_outl(CPUX86State *env, int addr, int val);
int cpu_x86_inb(CPUX86State *env, int addr);
int cpu_x86_inw(CPUX86State *env, int addr);
int cpu_x86_inl(CPUX86State *env, int addr);
#endif

CPUX86State *cpu_x86_init(void);
int cpu_x86_exec(CPUX86State *s);
void cpu_x86_interrupt(CPUX86State *s);
void cpu_x86_close(CPUX86State *s);

/* needed to load some predefinied segment registers */
void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector);

/* simulate fsave/frstor */
void cpu_x86_fsave(CPUX86State *s, uint8_t *ptr, int data32);
void cpu_x86_frstor(CPUX86State *s, uint8_t *ptr, int data32);

/* you can call this signal handler from your SIGBUS and SIGSEGV
   signal handlers to inform the virtual CPU of exceptions. non zero
   is returned if the signal was handled by the virtual CPU.  */
struct siginfo;
int cpu_x86_signal_handler(int host_signum, struct siginfo *info, 
                           void *puc);

/* used to debug */
#define X86_DUMP_FPU  0x0001 /* dump FPU state too */
#define X86_DUMP_CCOP 0x0002 /* dump qemu flag cache */
void cpu_x86_dump_state(CPUX86State *env, FILE *f, int flags);

/* page related stuff */
#define TARGET_PAGE_BITS 12
#define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS)
#define TARGET_PAGE_MASK ~(TARGET_PAGE_SIZE - 1)
#define TARGET_PAGE_ALIGN(addr) (((addr) + TARGET_PAGE_SIZE - 1) & TARGET_PAGE_MASK)

extern unsigned long real_host_page_size;
extern unsigned long host_page_bits;
extern unsigned long host_page_size;
extern unsigned long host_page_mask;

#define HOST_PAGE_ALIGN(addr) (((addr) + host_page_size - 1) & host_page_mask)

/* same as PROT_xxx */
#define PAGE_READ      0x0001
#define PAGE_WRITE     0x0002
#define PAGE_EXEC      0x0004
#define PAGE_BITS      (PAGE_READ | PAGE_WRITE | PAGE_EXEC)
#define PAGE_VALID     0x0008
/* original state of the write flag (used when tracking self-modifying
   code */
#define PAGE_WRITE_ORG 0x0010 

void page_dump(FILE *f);
int page_get_flags(unsigned long address);
void page_set_flags(unsigned long start, unsigned long end, int flags);
void page_unprotect_range(uint8_t *data, unsigned long data_size);

#endif /* CPU_I386_H */