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9bootfat: handle extended partitions

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This commit is contained in:
cinap_lenrek 2011-07-20 08:57:00 +02:00
parent 5be936a192
commit 76c3214389
1 changed files with 25 additions and 11 deletions
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22
sys/src/boot/pc/fat.c
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@ -314,7 +314,7 @@ conffat(Fat *fat, void *buf)
}
static int
findfat(Fat *fat, int drive)
findfat(Fat *fat, int drive, ulong xbase, ulong lba)
{
struct {
uchar status;
@ -327,22 +327,36 @@ findfat(Fat *fat, int drive)
uchar buf[Sectsz];
int i;
if(readsect(drive, 0, buf))
if(xbase == 0)
xbase = lba;
if(readsect(drive, lba, buf))
return -1;
if(buf[0x1fe] != 0x55 || buf[0x1ff] != 0xAA)
return -1;
p = (void*)&buf[0x1be];
for(i=0; i<4; i++){
switch(p[i].typ){
case 0x05:
case 0x0f:
case 0x85:
/* extended partitions */
if(!findfat(fat, drive, xbase, xbase + GETLONG(p[i].lba)))
return 0;
/* no break */
case 0x00:
continue;
default:
if(p[i].status != 0x80)
continue;
fat->drive = drive;
fat->partlba = *((ulong*)p[i].lba);
fat->partlba = lba + GETLONG(p[i].lba);
if(readsect(drive, fat->partlba, buf))
continue;
if(conffat(fat, buf))
continue;
return 0;
}
}
return -1;
}
@ -358,7 +372,7 @@ start(void *sp)
/* drive passed in DL */
drive = ((ushort*)sp)[5] & 0xFF;
if(findfat(&fat, drive)){
if(findfat(&fat, drive, 0, 0)){
print("no fat\r\n");
halt();
}