Date: Fri, 28 Oct 1994 12:31:49 GMT
From: gilliard AT lectra DOT fr (Laurent Pierre Gilliard)
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: serial interrupt

I want to read a serial port using serial interruption.
I've a program in BorlandC which is ok.
I've tried to change it for GCC but.... Searching help! Thanks.




#define GCC                     /* else TURBOC  */
#define COM     1               /* or 2                         */


#include <dos.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <io.h>
#include <fcntl.h>
#include <sys\stat.h>
#include <graphics.h>
#include <string.h>
#include <process.h>
#include <sys\types.h>
#ifdef GCC
        #include <dpmi.h>
        #include <pc.h>
#endif


#define FAUX    0
#define VRAI    1

#define ICR 0x20                /* Int Control reg       */
#define EOI 0x20                /* End of Int            */
#define IMR 0x21                /* Int Mask reg  */

#if COM==1
        #define IER 0x3F9       /* Int Enable     reg */
        #define IIR 0x3FA       /* Int Identif   reg */
        #define LSR 0x3FD       /* Line Status   reg */
        #define TDR 0x3F8       /* Transmit Data reg */
        #define RDR 0x3F8       /* Receive  Data reg */
        #define DLR 0x3FB       /* Divisor Latch reg */
        #define DRL 0x3F8       /* DLR Low               */
        #define DRH 0x3F9       /* DLR High              */
        #define MCR 0x3FC       /* Modem Control reg */
        #define LCR 0x3FB       /* Line Control  reg */
#else
        #define IER 0x2F9       /* Int Enable     reg */
        #define IIR 0x2FA       /* Int Identif   reg */
        #define LSR 0x2FD       /* Line Status   reg */
        #define TDR 0x2F8       /* Transmit Data reg */
        #define RDR 0x2F8       /* Receive  Data reg */
        #define DLR 0x2FB       /* Divisor Latch reg */
        #define DRL 0x2F8       /* DLR Low               */
        #define DRH 0x2F9       /* DLR High              */
        #define MCR 0x2FC       /* Modem Control reg */
        #define LCR 0x2FB       /* Line Control  reg */
#endif


        void                    InitLine(void);
#ifdef GCC
        void                    RSInt();
#else
        void interrupt          RSInt();
#endif
        void                            RestoreLine();


#ifdef GCC
        _go32_dpmi_seginfo      OldRS, new_handler;
#else
        void interrupt (*OldRS)();
#endif

struct {                                /* Save lines status */
        char imr,
                lcr,
                drl,
                drh,
                mcr,
                lsr;
} etat_ligne;

volatile char Caractere;


void InitLine(void) {
        char c;

        disable();
        etat_ligne.imr = inportb(IMR);
        etat_ligne.lcr = inportb(LCR);
        etat_ligne.drl = inportb(DRL);
        etat_ligne.drh = inportb(DRH);
        etat_ligne.mcr = inportb(MCR);
        etat_ligne.lsr = inportb(LSR);
        outportb(LCR,0x80);                     /* Init de la vitesse   */
        outportb(DRL,0x0C);                     /* 9600                                 */
        outportb(DRH,0);
        outportb(LCR,3);                        /* 8 bits, 1 de stop, pas de parite */
        outportb(MCR,0x08);

        outportb(IER,1);                        /* Generer int des que car present  */
        c = inportb(IMR);
        c &= COM==1 ? 0xEF : 0xF7;
        outportb(IMR,c);

#ifdef GCC
        _go32_dpmi_get_protected_mode_interrupt_vector(COM==1 ? 0x0C : 0x0B, &OldRS);

        new_handler.pm_offset = (int)RSInt;
        new_handler.pm_selector = _go32_my_cs();
        _go32_dpmi_chain_protected_mode_interrupt_vector(COM==1 ? 0x0C : 0x0B, &new_handler);
#else
        OldRS = getvect(COM==1 ? 0x0C : 0x0B);
        setvect(COM==1 ? 0x0C : 0x0B, RSInt);
#endif

        enable();
}


#ifdef GCC
        void RSInt() {
#else
        void interrupt RSInt() {
#endif
        unsigned etat;

        etat = inportb(LSR);            /* Line state */
        if (etat&1) {
                Caractere = inportb(RDR);
        }
        outportb(ICR,EOI);
}


void RestoreLine(void) {
        while (!(inportb(LSR)&0x20));   /* Wait end of transmission     */
        disable();
        outportb(IMR,etat_ligne.imr);
        outportb(LCR,etat_ligne.lcr);
        outportb(DRL,etat_ligne.drl);
        outportb(DRH,etat_ligne.drh);
        outportb(MCR,etat_ligne.mcr);
        outportb(LSR,etat_ligne.lsr);

        outportb(IER,0);                        /* End of interruptions */
#ifdef GCC
        _go32_dpmi_set_protected_mode_interrupt_vector(COM==1 ? 0x0C : 0x0B, &OldRS);
#else
        setvect(COM==1 ? 0x0C : 0x0B, OldRS);
#endif
        enable();
}


void main() {
        printf("Start\n");
        InitLine();

        while (1) {
                if(kbhit())
                        break;
                printf("%c\n",Caractere);
        }

        RestoreLine();
        printf("End\n");
}