This update adds the support for != 512 byte sector SCSI devices to

the sd & od drivers. There is also slight changes to fdisk & newfs
in order to comply with different sectorsizes.
Currently sectors of size 512, 1024 & 2048 are supported, the only
restriction beeing in fdisk, which hunts for the sectorsize of
the device.
This is based on patches to od.c and the other system files by
John Gumb & Barry Scott, minor changes and the sd.c patches by
me.
There also exist some patches for the msdos filesys code, but I
havn't been able to test those (yet).

	John Gumb (john@talisker.demon.co.uk)
	Barry Scott (barry@scottb.demon.co.uk)

1 files changed, 24 insertions, 5 deletions

diff --git a/sbin/i386/fdisk/fdisk.c b/sbin/i386/fdisk/fdisk.c
index b89d86571681..38506b58fc67 100644
--- a/sbin/i386/fdisk/fdisk.c
+++ b/sbin/i386/fdisk/fdisk.c
@@ -54,7 +54,9 @@ static char lbuf[LBUF];
 
 #define RoundCyl(x) ((((x) + cylsecs - 1) / cylsecs) * cylsecs)
 
-#define SECSIZE 512
+#define MAX_SEC_SIZE 2048	/* maximum section size that is supported */
+#define MIN_SEC_SIZE 512	/* the sector size to start sensing at */
+int secsize = 0;		/* the sensed sector size */
 
 const char *disk;
 const char *disks[] =
@@ -74,6 +76,8 @@ struct mboot
 	unsigned char bootinst[DOSPARTOFF];
 	struct	dos_partition parts[4];
 	unsigned short int	signature;
+	/* room to read in MBRs that are bigger then DEV_BSIZE */
+	unsigned char large_sector_overflow[MAX_SEC_SIZE-MIN_SEC_SIZE];
 };
 struct mboot mboot;
 
@@ -367,6 +371,7 @@ main(int argc, char *argv[])
 	    if (read_s0())
 		init_sector0(1);
 
+	    printf("Media sector size is %d\n", secsize);
 	    printf("Warning: BIOS sector numbering starts with sector 1\n");
 	    printf("Information from DOS bootblock is:\n");
 	    if (partition == -1)
@@ -433,7 +438,7 @@ struct dos_partition *partp = ((struct dos_partition *) &mboot.parts) + i;
 	printf("sysid %d,(%s)\n", partp->dp_typ, get_type(partp->dp_typ));
 	printf("    start %ld, size %ld (%ld Meg), flag %x\n",
 		partp->dp_start,
-		partp->dp_size, partp->dp_size * 512 / (1024 * 1024),
+		partp->dp_size, partp->dp_size * secsize / (1024 * 1024),
 		partp->dp_flag);
 	printf("\tbeg: cyl %d/ sector %d/ head %d;\n\tend: cyl %d/ sector %d/ head %d\n"
 		,DPCYL(partp->dp_scyl, partp->dp_ssect)
@@ -538,7 +543,7 @@ print_params()
 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
 			,cyls,heads,sectors,cylsecs);
 	if((dos_sectors > 63) || (dos_cyls > 1023) || (dos_heads > 255))
-		printf(" Figures below won't work with BIOS for partitions not in cyl 1\n");
+		printf("Figures below won't work with BIOS for partitions not in cyl 1\n");
 	printf("parameters to be used for BIOS calculations are:\n");
 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
 		,dos_cyls,dos_heads,dos_sectors,dos_cylsecs);
@@ -646,14 +651,28 @@ static ssize_t
 read_disk(off_t sector, void *buf)
 {
 	lseek(fd,(sector * 512), 0);
-	return read(fd, buf, 512);
+	if( secsize == 0 )
+		for( secsize = MIN_SEC_SIZE; secsize <= MAX_SEC_SIZE; secsize *= 2 )
+			{
+			/* try the read */
+			int size = read(fd, buf, secsize);
+			if( size == secsize )
+				/* it worked so return */
+				return secsize;
+			}
+	else
+		return read( fd, buf, secsize );
+
+	/* we failed to read at any of the sizes */
+	return -1;
 }
 
 static ssize_t
 write_disk(off_t sector, void *buf)
 {
 	lseek(fd,(sector * 512), 0);
-	return write(fd, buf, 512);
+	/* write out in the size that the read_disk found worked */
+	return write(fd, buf, secsize);
 }
 
 static int