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Copyright (c) 2026 Intel Corporation

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
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/// @file xed-dec-agen.c  
/// @brief decoder example with artificial AGEN (address generation) callbacks.

#include "xed/xed-interface.h"
#include "xed-examples-util.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h> //strcmp
#include <assert.h> 

int main(int argc, char** argv);


/* THIS IS JUST AN EXAMPLE FOR TESTING AND DOES NOT RETURN REAL DATA */
/* THIS IS JUST AN EXAMPLE FOR TESTING AND DOES NOT RETURN REAL DATA */
/* THIS IS JUST AN EXAMPLE FOR TESTING AND DOES NOT RETURN REAL DATA */
/* THIS IS JUST AN EXAMPLE FOR TESTING AND DOES NOT RETURN REAL DATA */

xed_uint64_t register_callback(xed_reg_enum_t reg, void* context, xed_bool_t* error) {
    (void) context;   // pacify compiler
    (void) error;

    /* After we register this function (see xed_agen_register_callback in
     * main()), this function is called as needed by xed_agen().  This
     * function provides register values for xed_agen(). In a real usage,
     * you would probably pass in a context (in your call to xed_agen())
     * that contains the actual values.  */

    
    /* Note that AL is required for the XLAT instruction. That is the only
       byte reg needed. Also note, that for real mode, raw segement
       selectors are returned by this function.  */

    /* in reality, you'd have to return valid values for each case */

    /* THIS IS JUST AN EXAMPLE FOR TESTING AND DOES NOT RETURN REAL DATA */
    
    switch(reg) {
      case XED_REG_RAX:
      case XED_REG_EAX:
      case XED_REG_AX:
        return 0xAABBCC00;
        break;
      case XED_REG_AL: // FOR XLAT
        break;

      case XED_REG_RCX:
      case XED_REG_ECX:
      case XED_REG_CX:
        return 0xAABBCCDD;
        break;
      case XED_REG_RDX:
      case XED_REG_EDX:
      case XED_REG_DX:
        break;
      case XED_REG_RBX:
      case XED_REG_EBX:
      case XED_REG_BX:
        return 0x11223344;
        break;
      case XED_REG_RSP:
      case XED_REG_ESP:
      case XED_REG_SP:
        break;
      case XED_REG_RBP:
      case XED_REG_EBP:
      case XED_REG_BP:
        break;
      case XED_REG_RSI:
      case XED_REG_ESI:
      case XED_REG_SI:
        return 0x1122334455;
        break;
      case XED_REG_RDI:
      case XED_REG_EDI:
      case XED_REG_DI:
        return 0x6655443322;
        break;
      case XED_REG_R8:
      case XED_REG_R8D:
      case XED_REG_R8W:
        break;
      case XED_REG_R9:
      case XED_REG_R9D:
      case XED_REG_R9W:
        break;
      case XED_REG_R10:
      case XED_REG_R10D:
      case XED_REG_R10W:
        break;
      case XED_REG_R11:
      case XED_REG_R11D:
      case XED_REG_R11W:
        break;
      case XED_REG_R12:
      case XED_REG_R12D:
      case XED_REG_R12W:
        break;
      case XED_REG_R13:
      case XED_REG_R13D:
      case XED_REG_R13W:
        break;
      case XED_REG_R14:
      case XED_REG_R14D:
      case XED_REG_R14W:
        break;
      case XED_REG_R15:
      case XED_REG_R15D:
      case XED_REG_R15W:
        break;
      case XED_REG_RIP:
        return 0x7990100020003000ULL;

      case XED_REG_EIP:
      case XED_REG_IP:
        break;
      case XED_REG_CS:
      case XED_REG_DS:
      case XED_REG_ES:
      case XED_REG_SS:
      case XED_REG_FS:
      case XED_REG_GS:
        break;
      default:
        assert(0);
    }
    return 0;
}

xed_uint64_t segment_callback(xed_reg_enum_t reg, void* context, xed_bool_t* error) {
    /* for protected mode, this function returns the valid segment base values */

    /* in reality, you'd have to return valid valies for each case */
    /* THIS IS JUST AN EXAMPLE FOR TESTING AND DOES NOT RETURN REAL DATA */

    (void) context;   // pacify compiler
    (void) error;
    
    switch(reg) {
      case XED_REG_CS:
      case XED_REG_DS:
      case XED_REG_ES:
      case XED_REG_SS:
        return 0;
      case XED_REG_FS:
        return 0;
        break;
      case XED_REG_GS:
        return 0;
        break;
      default:
        assert(0);
        break;
    }
    return 0;
}




int 
main(int argc, char** argv)
{
    xed_error_enum_t xed_error;

    xed_bool_t long_mode = 0;
    xed_bool_t real_mode = 0;
    xed_bool_t protected_16 = 0;
    xed_state_t dstate;
    unsigned int first_argv;
    unsigned int bytes = 0;
    unsigned char itext[XED_MAX_INSTRUCTION_BYTES];
    unsigned int i;
    unsigned int argcu = (unsigned int)argc;
    unsigned int u;
    xed_decoded_inst_t xedd;
#define BUFLEN  1000
    char buffer[BUFLEN];
    xed_bool_t ok;
    unsigned int isyntax;
    xed_syntax_enum_t syntax;
    unsigned int memop_index = 0;    
    unsigned int memops = 0;
    xed_uint64_t out_addr = 0;

    xed_tables_init();

    // register callbacks that provide actual values. These functions will
    // be called by xed_agen() later on when values are needed.
    xed_agen_register_callback( register_callback, segment_callback);

    xed_state_zero(&dstate);
    //xed_set_verbosity( 99 );

    if (argcu > 2 && strcmp(argv[1], "-64") == 0) 
        long_mode = 1;
    if (argcu > 2 && strcmp(argv[1], "-r") == 0) 
        real_mode = 1;
    if (argcu > 2 && strcmp(argv[1], "-16") == 0) 
        protected_16 = 1;

    if (long_mode) {
        first_argv = 2;
        dstate.mmode=XED_MACHINE_MODE_LONG_64;
    }
    else if (protected_16) {
        first_argv = 2;
        xed_state_init(&dstate,
                       XED_MACHINE_MODE_LEGACY_16,
                       XED_ADDRESS_WIDTH_16b, 
                       XED_ADDRESS_WIDTH_16b);
    }
    else if (real_mode) {
        first_argv = 2;
        /* we say that real mode uses 16b addressing even though the
           addresses returned are 20b long. */
        xed_state_init(&dstate,
                       XED_MACHINE_MODE_REAL_16,
                       XED_ADDRESS_WIDTH_16b,
                       XED_ADDRESS_WIDTH_16b);
    }
    else {
        first_argv=1;
        xed_state_init(&dstate,
                       XED_MACHINE_MODE_LEGACY_32, 
                       XED_ADDRESS_WIDTH_32b, 
                       XED_ADDRESS_WIDTH_32b);
    }

    xed_decoded_inst_zero_set_mode(&xedd, &dstate);
    for( i=first_argv ;i < argcu; i++)    {
        xed_uint8_t x = (xed_uint8_t)(xed_atoi_hex(argv[i]));
        assert(bytes < XED_MAX_INSTRUCTION_BYTES);
        itext[bytes++] = x;
    }
    if (bytes == 0)    {
        fprintf(stderr, "Must supply some hex bytes\n");
        exit(1);
    }

    printf("PARSING BYTES: ");
    for( u=0;u<bytes; u++) 
        printf("%02x ", XED_STATIC_CAST(unsigned int,itext[u]));
    printf("\n");

    // call XED decode
    
    xed_error = xed_decode(&xedd, 
                           XED_REINTERPRET_CAST(const xed_uint8_t*,itext),
                           bytes);
    switch(xed_error)
    {
      case XED_ERROR_NONE:
        break;
      case XED_ERROR_BUFFER_TOO_SHORT:
        fprintf(stderr,"Not enough bytes provided\n");
        exit(1);
      case XED_ERROR_GENERAL_ERROR:
        fprintf(stderr,"Could not decode given input.\n");
        exit(1);
      default:
        fprintf(stderr,"Unhandled error code %s\n", xed_error_enum_t2str(xed_error));
        exit(1);
    }

    // print the output a few different ways
    printf("iclass: %s\n",
           xed_iclass_enum_t2str(xed_decoded_inst_get_iclass(&xedd)));
    printf("iform: %s\n", 
           xed_iform_enum_t2str(xed_decoded_inst_get_iform_enum(&xedd)));

    for(isyntax=  XED_SYNTAX_XED; isyntax < XED_SYNTAX_LAST; isyntax++)    {
        syntax = XED_STATIC_CAST(xed_syntax_enum_t, isyntax);
        ok = xed_format_context(syntax, &xedd, buffer, BUFLEN, 0, 0, 0);
        if (ok)
            printf("%s syntax: %s\n", xed_syntax_enum_t2str(syntax), buffer);
        else
            printf("Error disassembling %s syntax\n", xed_syntax_enum_t2str(syntax));
    }

    memops = xed_decoded_inst_number_of_memory_operands(&xedd);
    printf("\nNumber of memory operands: %d\n", (int)memops);

    // call the address generation (agen) calculator for each memop.
    //  It will  call the  callbacks you registered at top of main().
    
    for(memop_index=0;memop_index<memops;memop_index++) {
        // The  "context" passed to your registered callbacks when they are asked
        // to produce values. In this example we don't require a real context.
        void* context = 0;
        xed_error = xed_agen(&xedd, memop_index, context, &out_addr);
        if (xed_error != XED_ERROR_NONE) {
            fprintf(stderr,"Agen error code %s\n", xed_error_enum_t2str(xed_error));
            exit(1);
        }
        printf("\tMemory agen%d: 0x" XED_FMT_LX16 "\n", (int)memop_index, out_addr);
    }
    return 0;
}
