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#if (TRY_FLOPPY_FIRST > 0)
/*
* 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; either version 2, or (at
* your option) any later version.
*/
#include "etherboot.h"
#define BOOTSECT ((char *)0x7C00)
#define BOOTSIG ((unsigned short *)BOOTSECT)[0xFF]
#define PARTTAB ((partentry *)(BOOTSECT+0x1BE))
typedef struct partentry {
unsigned char flags;
unsigned char start_head;
unsigned char start_sector;
unsigned char start_cylinder;
unsigned char type;
unsigned char end_head;
unsigned char end_sector;
unsigned char end_cylinder;
unsigned long offset;
unsigned long length;
} partentry;
static unsigned int disk_read_retry(int dev,int c,int h,int s)
{
int retry = 3,rc;
while (retry-- && (rc = pcbios_disk_read(dev,c,h,s,BOOTSECT)) != 0);
if (BOOTSIG != 0xAA55) {
printf("not a boot sector");
return(0xFFFF); }
return(rc);
}
int bootdisk(int dev,int part)
{
int rc;
disk_init();
if ((rc = disk_read_retry(dev,0,0,1)) != 0) {
readerr:
if (rc != 0xFFFF)
printf("read error (%#hhX)",rc/256);
return(0); }
if (part) {
partentry *ptr;
if (part >= 5) {
int i;
for (i = 0, ptr = PARTTAB; ptr->type != 5; ptr++)
if (++i == 4) {
printf("partition not found");
return(0); }
if ((rc = disk_read_retry(dev,
ptr->start_cylinder,
ptr->start_head,
ptr->start_sector)) != 0)
goto readerr;
part -= 4; }
if (!(ptr = PARTTAB-1+part)->type) {
printf("empty partition");
return(0); }
if ((rc = disk_read_retry(dev,
ptr->start_cylinder,
ptr->start_head,
ptr->start_sector)) != 0)
goto readerr; }
cleanup();
gateA20_unset();
/* Set %edx to device number to emulate BIOS
Fortunately %edx is not used after this */
__asm__("movl %0,%%edx" : : "g" (dev));
xstart((unsigned long)BOOTSECT, 0, 0);
return(0);
}
#endif
/*
* Local variables:
* c-basic-offset: 8
* End:
*/
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