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/* -*- c -*- ------------------------------------------------------------- *
*
* Copyright 2003-2004 H. Peter Anvin - All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, Inc., 53 Temple Place Ste 330,
* Boston MA 02111-1307, USA; either version 2 of the License, or
* (at your option) any later version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
/* $Id: mdiskchk.c,v 1.7 2004/12/30 21:57:12 hpa Exp $ */
/*
* mdiskchk.c
*
* DOS program to check for the existence of a memdisk.
*
* This program can be compiled for DOS with the OpenWatcom compiler
* (http://www.openwatcom.org/):
*
* wcl -3 -osx -mt mdiskchk.c
*/
#include <stdio.h>
#include <string.h>
#include <i86.h> /* For MK_FP() */
typedef unsigned long uint32_t;
typedef unsigned short uint16_t;
typedef unsigned char uint8_t;
struct memdiskinfo {
uint16_t bytes; /* Bytes from memdisk */
uint16_t version; /* Memdisk version */
uint32_t base; /* Base of disk in high memory */
uint32_t size; /* Size of disk in sectors */
char far * cmdline; /* Command line */
void far * oldint13; /* Old INT 13h */
void far * oldint15; /* Old INT 15h */
uint16_t olddosmem;
uint8_t bootloaderid;
uint8_t _pad;
/* We add our own fields at the end */
int cylinders;
int heads;
int sectors;
};
struct memdiskinfo * query_memdisk(int drive)
{
static struct memdiskinfo mm;
uint32_t _eax, _ebx, _ecx, _edx;
uint16_t _es, _di;
unsigned char _dl = drive;
uint16_t bytes;
__asm {
.386 ;
mov eax, 454d0800h ;
mov ecx, 444d0000h ;
mov edx, 53490000h ;
mov dl, _dl ;
mov ebx, 3f4b0000h ;
int 13h ;
mov _eax, eax ;
mov _ecx, ecx ;
mov _edx, edx ;
mov _ebx, ebx ;
mov _es, es ;
mov _di, di ;
}
if ( _eax >> 16 != 0x4d21 ||
_ecx >> 16 != 0x4d45 ||
_edx >> 16 != 0x4944 ||
_ebx >> 16 != 0x4b53 )
return NULL;
memset(&mm, 0, sizeof mm);
bytes = *(uint16_t far *)MK_FP(_es, _di);
/* 27 is the most we know how to handle */
if ( bytes > 27 )
bytes = 27;
_fmemcpy((void far *)&mm, (void far *)MK_FP(_es,_di), bytes);
mm.cylinders = ((_ecx >> 8) & 0xff) + ((_ecx & 0xc0) << 2) + 1;
mm.heads = ((_edx >> 8) & 0xff) + 1;
mm.sectors = (_ecx & 0x3f);
return &mm;
}
const char *bootloadername(uint8_t id)
{
static const struct {
uint8_t id, mask;
const char *name;
} *lp, list[] =
{
{ 0x10, 0xf0, "LILO" },
{ 0x20, 0xf0, "LOADLIN" },
{ 0x31, 0xff, "SYSLINUX" },
{ 0x32, 0xff, "PXELINUX" },
{ 0x33, 0xff, "ISOLINUX" },
{ 0x34, 0xff, "EXTLINUX" },
{ 0x30, 0xf0, "SYSLINUX family" },
{ 0x40, 0xf0, "Etherboot" },
{ 0x50, 0xf0, "ELILO" },
{ 0x70, 0xf0, "GrUB" },
{ 0x80, 0xf0, "U-Boot" },
{ 0x00, 0x00, "unknown" }
};
for ( lp = list ; ; lp++ ) {
if ( ((id ^ lp->id) & lp->mask) == 0 )
return lp->name;
}
}
int main(int argc, char *argv[])
{
int d;
int found = 0;
struct memdiskinfo *m;
for ( d = 0 ; d <= 0xff ; d++ ) {
if ( (m = query_memdisk(d)) != NULL ) {
printf("Drive %02X is MEMDISK %u.%02u:\n"
"\tAddress = 0x%08lx, len = %lu sectors, chs = %u/%u/%u,\n"
"\tloader = 0x%02x (%s),\n"
"\tcmdline = %Fs\n",
d, m->version >> 8, m->version & 0xff,
m->base, m->size, m->cylinders, m->heads, m->sectors,
m->bootloaderid, bootloadername(m->bootloaderid),
m->cmdline);
found++;
}
}
return found;
}
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