ECRITURE D'UN *.COM 16 BITS

// En-têtes:
#include <stdio.h>
#include <list>


// Classe CCode:
class CCode
{
    private:

        // Structure:
        struct txxh
        {
            int xxh[3];
            int adr[3];
        };

    public:

        // Constructeur par défaut:
        CCode(char* buffer = 0, int adr = 0, int num_xxh = 0, int xxh_1 = 0, int xxh_2 = 0, int xxh_3 = 0)
        {
            this->buffer  = buffer;
            this->adr     = adr;
            this->num_xxh = num_xxh;

            this->xxh.xxh[0] = xxh_1;
            this->xxh.adr[0] = adr + 0;

            this->xxh.xxh[1] = xxh_2;
            this->xxh.adr[1] = adr + 1;

            this->xxh.xxh[2] = xxh_3;
            this->xxh.adr[2] = adr + 2;
        }

        // Données:
        char* buffer;
        int   adr;
        int   num_xxh;
        txxh  xxh;
};


// Types:
typedef std::list<CCode*> LCODE;


// Classe CCom16b:
class CCom16b
{
    public:

        // Constructeur par défaut:
        CCom16b()
        {
            // Création du fichier en mode écriture:
            m_pFile  = fopen("code_16_bits.com", "w");

            // Initialisation des adresses:
            m_Adr = 0x00;
        }

        // Destructeur:
        ~CCom16b()
        {
            // Fermeture du fichier en mode écriture:
            fclose(m_pFile);

            // Lance le fichier:
            printf("\nLancement du code:\n");
            system("code_16_bits.com");
        }

        // mov ah,xxh:
        void Set_mov_ah_xxh(int xxh)
        {
            char* buffer = new char[256];
            sprintf(buffer, "mov ah,%.2xh", xxh);

            m_pCode.push_back(new CCode(buffer, m_Adr, 2, 0xB4, xxh));
            m_Adr += 2;
        }

        // int xxh:
        void Set_int_xxh(int xxh)
        {
            char* buffer = new char[256];
            sprintf(buffer, "int %.2xh", xxh);

            m_pCode.push_back(new CCode(buffer, m_Adr, 2, 0xCD, xxh));
            m_Adr += 2;
        }

        // mov dx,xxh:
        void Set_mov_dx_xxh(int xxh)
        {
            int xxh_1 = 0, xxh_2 = 0, xxh_3 = 0;
            LittleEndian(xxh, &xxh_1, &xxh_2, &xxh_3);
            
            char* buffer = new char[256];
            sprintf(buffer, "mov dx,%.2xh", xxh);
            
            if (xxh_2 == 0x00 && xxh_3 == 0x00)
            {
                m_pCode.push_back(new CCode(buffer, m_Adr, 2, 0xBA, xxh_1));
                m_Adr += 2;
            }
            else if (xxh_3 == 0x00)
            {
                m_pCode.push_back(new CCode(buffer, m_Adr, 3, 0xBA, xxh_1, xxh_2));
                m_Adr += 3;
            }
        }

        // Variable buffer:
        void SetBuffer(int adr, char* buffer)
        {
             m_Adr = adr - 0x0100; // Car l'adresse du début du code com16b est 0x0100:
             for (int i = 0; i < (int)strlen(buffer); i++)
             {
                 m_pCode.push_back(new CCode(buffer, m_Adr, 1, buffer[i]));
                 m_Adr++;
             }
        }

        // Ecriture du code:
        void WriteCode()
        {
            for (LCODE::iterator itor = m_pCode.begin(); itor != m_pCode.end(); ++itor)
            {
                if ( (*itor)->num_xxh == 1)
                {
                    fseek(m_pFile, (*itor)->xxh.adr[0], SEEK_SET);
                    fprintf(m_pFile, "%c", (*itor)->xxh.xxh[0]);
                }
                else if ( (*itor)->num_xxh == 2)
                {
                    fseek(m_pFile, (*itor)->xxh.adr[0], SEEK_SET);
                    fprintf(m_pFile, "%c", (*itor)->xxh.xxh[0]);

                    fseek(m_pFile, (*itor)->xxh.adr[1], SEEK_SET);
                    fprintf(m_pFile, "%c", (*itor)->xxh.xxh[1]);
                }
                else if ( (*itor)->num_xxh == 3)
                {
                    fseek(m_pFile, (*itor)->xxh.adr[0], SEEK_SET);
                    fprintf(m_pFile, "%c", (*itor)->xxh.xxh[0]);

                    fseek(m_pFile, (*itor)->xxh.adr[1], SEEK_SET);
                    fprintf(m_pFile, "%c", (*itor)->xxh.xxh[1]);

                    fseek(m_pFile, (*itor)->xxh.adr[2], SEEK_SET);
                    fprintf(m_pFile, "%c", (*itor)->xxh.xxh[2]);
                }
            }
        }

        // Affichege du code:
        void ShowCode()
        {
            printf("ADR\t\tHEXA\t\tASM\n");

            for (LCODE::iterator itor = m_pCode.begin(); itor != m_pCode.end(); ++itor)
            {
                if ( (*itor)->num_xxh == 1)
                {
                    printf("%.4X\t|\t%.6X%\t|\t%s\n", (*itor)->adr + 0x0100,
                                                      (*itor)->xxh.xxh[0],
                                                      (*itor)->buffer);
                }
                if ( (*itor)->num_xxh == 2)
                {
                    printf("%.4X\t|\t00%.2X%.2X\t|\t%s\n", (*itor)->adr + 0x0100,
                                                           (*itor)->xxh.xxh[0],
                                                           (*itor)->xxh.xxh[1],
                                                           (*itor)->buffer);
                }
                else if ( (*itor)->num_xxh == 3)
                {
                    printf("%.4X\t|\t%.2X%.2X%.2X\t|\t%s\n", (*itor)->adr + 0x0100,
                                                             (*itor)->xxh.xxh[0],
                                                             (*itor)->xxh.xxh[1],
                                                             (*itor)->xxh.xxh[2],
                                                             (*itor)->buffer);
                }
            }
        }

    private:

        // LittleEndian:
        /*
             lsb      msb
            -------------
            |78|56|34|12|
            -------------
                       .
                      /|\
                       |
                       |
               Adresse du suivant
                       |
                       |
                ----   |
            msb |12| <--
                ----
                |34|
                ----
                |56|
                ----
            lsb |78|
                ----
                
            Ex: 0x0210h -> 0x10 0x02
        */
        void LittleEndian(int xxh, int* xxh_1, int* xxh_2, int* xxh_3)
        {
            char buffer[6] = {0};
            sprintf(buffer, "%.6X", xxh);

            char part1[2] = {0};
            for (int i = 0; i < 2; i++) part1[i - 0] = buffer[i];
            (*xxh_3) = BufferToHexa(part1);

            char part2[2] = {0};
            for (int i = 2; i < 4; i++) part2[i - 2] = buffer[i];
            (*xxh_2) = BufferToHexa(part2);

            char part3[2] = {0};
            for (int i = 4; i < 6; i++) part3[i - 4] = buffer[i];
            (*xxh_1) = BufferToHexa(part3);
        }

        // Convertion d'une chaine de caractères en hexadécimal:        
        int BufferToHexa(char* buffer)
        {
            int c[2];

            for (int i = 0; i < 2; i++)
            {
                switch (buffer[i])
                {
                    case '0' : c[i] = 0; break;
                    case '1' : c[i] = 1; break;
                    case '2' : c[i] = 2; break;
                    case '3' : c[i] = 3; break;
                    case '4' : c[i] = 4; break;
                    case '5' : c[i] = 5; break;
                    case '6' : c[i] = 6; break;
                    case '7' : c[i] = 7; break;
                    case '8' : c[i] = 8; break;
                    case '9' : c[i] = 9; break;
                    case 'A' : c[i] = 10; break;
                    case 'a' : c[i] = 10; break;
                    case 'B' : c[i] = 11; break;
                    case 'b' : c[i] = 11; break;
                    case 'C' : c[i] = 12; break; 
                    case 'c' : c[i] = 12; break;
                    case 'D' : c[i] = 13; break;
                    case 'd' : c[i] = 13; break;
                    case 'E' : c[i] = 14; break;
                    case 'e' : c[i] = 14; break;
                    case 'f' : c[i] = 15; break;
                    case 'F' : c[i] = 15; break;
                }
            }

            return ( (c[0] * 16) + c[1] );
        }

    private:

        // Données membres:
        FILE*          m_pFile; 
        LCODE          m_pCode;
        unsigned int   m_Adr;
};


int main(void)
{
    CCom16b com16b;

    com16b.Set_mov_ah_xxh(0x09);
    com16b.Set_mov_dx_xxh(0x10F);
    com16b.Set_int_xxh(0x21);

    com16b.Set_mov_ah_xxh(0x00);
    com16b.Set_int_xxh(0x16);

    com16b.Set_mov_ah_xxh(0x00);
    com16b.Set_int_xxh(0x21);

    com16b.SetBuffer(0x10F, "Hello World !$");

    com16b.WriteCode();

    com16b.ShowCode();

    return 0;
}