ref: 14510c867d15cbd0de68319b428b734a301317e0
parent: ca37b188d2da25bf88f28a79c84befb1b3015f5f
author: ment <[email protected]>
date: Wed Apr 27 19:23:17 EDT 2011
variable PBS code offset
--- a/sys/src/cmd/disk/format.c
+++ b/sys/src/cmd/disk/format.c
@@ -442,9 +442,9 @@
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 @@
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 @@
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);