usr/src/cmd/standalone/tm.c

#

/*
 * TM tape driver
 */

#include <sys/param.h>
#include <sys/inode.h>
#include "saio.h"

struct device {
        int     tmer;
        int     tmcs;
        int     tmbc;
        char    *tmba;
        int     tmdb;
        int     tmrd;
};

#define TMADDR ((struct device *)0172520)

#define GO      01
#define RCOM    02
#define WCOM    04
#define WEOF    06
#define SFORW   010
#define SREV    012
#define WIRG    014
#define REW     016
#define DENS    060000          /* 9-channel */
#define IENABLE 0100
#define CRDY    0200
#define GAPSD   010000
#define TUR     1
#define SDWN    010
#define HARD    0102200 /* ILC, EOT, NXM */
#define EOF     0040000

#define SSEEK   1
#define SIO     2


tmrew(io)
register struct iob *io;
{
        tmstrategy(io, REW);
}

tmopen(io)
register struct iob *io;
{
        register skip;

        tmstrategy(io, REW);
        skip = io->i_boff;
        while (skip--) {
                io->i_cc = 0;
                while (tmstrategy(io, SFORW))
                        ;
        }
}
tmstrategy(io, func)
register struct iob *io;
{
        register int com, unit, errcnt;

        unit = io->i_unit;
        errcnt = 0;
retry:
        tmquiet();
        com = (unit<<8)|(segflag<<4)|DENS;
        TMADDR->tmbc = -io->i_cc;
        TMADDR->tmba = io->i_ma;
        if (func == READ)
                TMADDR->tmcs = com | RCOM | GO;
        else if (func == WRITE)
                TMADDR->tmcs = com | WCOM | GO;
        else if (func == SREV) {
                TMADDR->tmbc = -1;
                TMADDR->tmcs = com | SREV | GO;
                return(0);
        } else
                TMADDR->tmcs = com | func | GO;
        while ((TMADDR->tmcs&CRDY) == 0)
                ;
        if (TMADDR->tmer&EOF)
                return(0);
        if (TMADDR->tmer < 0) {
                if (errcnt == 0)
                        printf("tape error: er=%o", TMADDR->tmer);
                if (errcnt==10) {
                        printf("\n");
                        return(-1);
                }
                errcnt++;
                tmstrategy(io, SREV);
                goto retry;
        }
        if (errcnt)
                printf(" recovered by retry\n");
        return( io->i_cc+TMADDR->tmbc );
}

tmquiet()
{
        while ((TMADDR->tmcs&CRDY) == 0)
                ;
        while ((TMADDR->tmer&TUR) == 0)
                ;
        while ((TMADDR->tmer&SDWN) != 0)
                ;
}