.ref-Research-V6/usr/sys/dmr/mem.c

#
/*
 */

/*
 *      Memory special file
 *      minor device 0 is physical memory
 *      minor device 1 is kernel memory
 *      minor device 2 is EOF/RATHOLE
 */

#include "../param.h"
#include "../user.h"
#include "../conf.h"
#include "../seg.h"

mmread(dev)
{
        register c, bn, on;
        int a, d;

        if(dev.d_minor == 2)
                return;
        do {
                bn = lshift(u.u_offset, -6);
                on = u.u_offset[1] & 077;
                a = UISA->r[0];
                d = UISD->r[0];
                spl7();
                UISA->r[0] = bn;
                UISD->r[0] = 077406;
                if(dev.d_minor == 1)
                        UISA->r[0] = (ka6-6)->r[(bn>>7)&07] + (bn & 0177);
                c = fuibyte(on);
                UISA->r[0] = a;
                UISD->r[0] = d;
                spl0();
        } while(u.u_error==0 && passc(c)>=0);
}

mmwrite(dev)
{
        register c, bn, on;
        int a, d;

        if(dev.d_minor == 2) {
                c = u.u_count;
                u.u_count = 0;
                u.u_base =+ c;
                dpadd(u.u_offset, c);
                return;
        }
        for(;;) {
                bn = lshift(u.u_offset, -6);
                on = u.u_offset[1] & 077;
                if ((c=cpass())<0 || u.u_error!=0)
                        break;
                a = UISA->r[0];
                d = UISD->r[0];
                spl7();
                UISA->r[0] = bn;
                UISD->r[0] = 077406;
                if(dev.d_minor == 1)
                        UISA->r[0] = (ka6-6)->r[(bn>>7)&07] + (bn & 0177);
                suibyte(on, c);
                UISA->r[0] = a;
                UISD->r[0] = d;
                spl0();
        }
}