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#ident "$Id: fd.c,v 1.2 2004/12/14 22:46:25 hpa Exp $"
/* ----------------------------------------------------------------------- *
*
* Copyright 2003 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.
*
* ----------------------------------------------------------------------- */
/*
* fd.c
*
* Chainload a floppy disk (currently rather braindead.)
*/
#include <com32.h>
#define NULL ((void *)0)
int printf(const char *, ...);
unsigned int atou(const char *);
int __start(void)
{
int whichfd = atou(__com32.cs_cmdline);
static com32sys_t inreg, outreg; /* In bss, so zeroed automatically */
int retry;
for ( retry = 0 ; retry < 6 ; retry++ ) {
printf(">");
inreg.eax.w[0] = 0x0201; /* Read one sector */
inreg.ecx.w[0] = 0x0001; /* Cyl 0 sector 1 */
inreg.edx.b[1] = 0; /* Head 0 */
inreg.edx.b[0] = whichfd; /* Drive number */
inreg.es = SEG(__com32.cs_bounce); /* Read into the bounce buffer */
inreg.ebx.w[0] = OFFS(__com32.cs_bounce);
__com32.cs_intcall(0x13, &inreg, &outreg);
if ( (outreg.eflags.l & 1) == 0 )
break;
}
if ( (outreg.eflags.l & 1) == 0 ) {
printf("!\n");
inreg.eax.w[0] = 0x000d;
inreg.edx.w[0] = 0;
inreg.edi.l = (uint32_t) __com32.cs_bounce;
inreg.ecx.l = 512;
inreg.ebx.l = whichfd & 0xff;
inreg.esi.l = 0; /* No partitions */
inreg.ds = 0; /* No partitions */
__com32.cs_intcall(0x22, &inreg, NULL);
}
/* If we get here, badness happened */
return 255;
}
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