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variable PBS code offset

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ment 2011-04-27 23:23:17 +02:00
parent ca37b188d2
commit 14510c867d
1 changed files with 16 additions and 7 deletions
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23
sys/src/cmd/disk/format.c
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@ -442,9 +442,9 @@ dosfs(int dofat, int dopbs, Disk *disk, char *label, int argc, char *argv[], int
memmove(b->version, "Plan9.00", sizeof(b->version));
/*
* Add bootstrapping code; assume it starts
* at 0x3E (the destination of the jump we just
* wrote to b->magic).
* Add bootstrapping code; offset is
* determined from short jump (0xEB 0x??)
* instruction.
*/
if(dopbs) {
pbsbuf = malloc(secsize);
@ -466,11 +466,15 @@ dosfs(int dofat, int dopbs, Disk *disk, char *label, int argc, char *argv[], int
memmove(pbsbuf, bootprog, sizeof(bootprog));
npbs = nbootprog;
}
if(npbs <= 0x3E)
n = buf[1] + 2;
if(npbs <= 0x3 || npbs < n)
fprint(2, "warning: pbs too small\n");
else
memmove(buf+0x3E, pbsbuf+0x3E, npbs-0x3E);
else if(buf[0] != 0xEB)
fprint(2, "warning: pbs doesn't start with short jump\n");
else{
memmove(buf, pbsbuf, 3);
memmove(buf+n, pbsbuf+n, npbs-n);
}
free(pbsbuf);
}
@ -558,6 +562,11 @@ if(chatty) print("driveno = %ux\n", b->driveno);
b->bootsig = 0x29;
x = disk->offset + b->nfats*fatsecs + nresrv;
PUTLONG(b->volid, x);
/*
* FAT32 9boot PBS requires volid at this
* offset even for FAT16/FAT12 partitions.
*/
PUTLONG(b->volid+28, x);
if(chatty) print("volid = %lux %lux\n", x, GETLONG(b->volid));
memmove(b->label, label, sizeof(b->label));
sprint(r, "FAT%d ", fatbits);