date and time created 91/05/12 22:30:02 by william

[unix-history] / usr / src / sys / i386 / stand / mem.c

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* %sccs.include.noredist.c%
*
*      @(#)mem.c       7.1 (Berkeley) %G%
*/

/*
* Scan physical memory and talley, bypassing AT devices/roms
*/
#define CHK     4096
main() {
       long base;
       register long val;

       base = 0;
       do {
               printf("0x%X - ", base);
               for ( ;; base+= CHK) {
                       if (base >= 0xa0000 && base <= 0xe0000) break;
                       if (base >= 0xfffff000) break;
                       val = *((long *) base);
                       *((long *) base) = base*4 + 0x55555555;
                       if (*((long *) base) != base*4 + 0x55555555) {
                               *((long *) base) = val ;
                               break;
                       }
                       *((long *) base) = val ;
               }
               printf("0x%X\n", base-CHK) ;
               for ( ;; base+= CHK) {
                       if (base >= 0xa0000 && base <= 0xe0000) continue ;
                       if (base >= 0xfffff000) break;
                       val = *((long *) base);
                       *((long *) base) = base*4 + 0x55555555;
                       if (*((long *) base) == base*4 + 0x55555555) {
                               *((long *) base) = val ;
                               break;
                       }
               }
       } while (base < 0xfffff000); 
       printf("finished\n");
       getchar();
}