The value of -l should be treated as a 512-byte block count.

Tweak man page.

diff --git a/sbin/fdisk/fdisk.8 b/sbin/fdisk/fdisk.8
index 780ac3c..c83ddb6 100644 (file)
--- a/sbin/fdisk/fdisk.8
+++ b/sbin/fdisk/fdisk.8
@@ -1,4 +1,4 @@
-.\"    $OpenBSD: fdisk.8,v 1.103 2021/06/22 15:01:55 jmc Exp $
+.\"    $OpenBSD: fdisk.8,v 1.104 2021/06/23 13:07:13 krw Exp $
 .\"
 .\"
 .\" Copyright (c) 1997 Tobias Weingartner
@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: June 22 2021 $
+.Dd $Mdocdate: June 23 2021 $
 .Dt FDISK 8
 .Os
 .Sh NAME
@@ -144,8 +144,7 @@ MBR partition containing all available space not allocated by a
 .Fl b
 specification.
 .It Fl l Ar blocks
-Specify the number of blocks in the disk, and force the MBR to be in LBA
-mode only.
+Treat the disk as if it has the specified number of blocks.
 .It Fl u
 Update MBR bootcode, preserving existing MBR partition table.
 The MBR bootcode extends from offset 0x000 to the start of the MBR partition

diff --git a/sbin/fdisk/fdisk.c b/sbin/fdisk/fdisk.c
index d6fee5a..c76ae1f 100644 (file)
--- a/sbin/fdisk/fdisk.c
+++ b/sbin/fdisk/fdisk.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: fdisk.c,v 1.111 2021/06/22 14:01:58 krw Exp $ */
+/*     $OpenBSD: fdisk.c,v 1.112 2021/06/23 13:07:13 krw Exp $ */
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -165,6 +165,15 @@ main(int argc, char *argv[])
                b_sectors = DL_BLKTOSEC(&dl, b_sectors);
                b_offset = DL_BLKTOSEC(&dl, b_offset);
        }
+       if (l_arg > 0) {
+               if (l_arg % bps != 0)
+                       l_arg += bps - l_arg % bps;
+               l_arg = DL_BLKTOSEC(&dl, l_arg);
+               disk.cylinders = l_arg / 64;
+               disk.heads = 1;
+               disk.sectors = 64;
+               disk.size = l_arg;
+       }
 
        /* "proc exec" for man page display */
        if (pledge("stdio rpath wpath disklabel proc exec", NULL) == -1)