From: krw <krw@openbsd.org>
Date: Wed, 1 Dec 2021 22:37:30 +0000 (+0000)
Subject: Remove the MBR_init() "#ifdef defined(__macppc__) ||
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=354eded82a987a0032db0f12e45cbfbadee14669;p=openbsd

Remove the MBR_init() "#ifdef defined(__macppc__) ||
defined(__mips__)" chunk that rounded the start of the default
OpenBSD partition to a cylinder boundary. The value has been
immediately re-rounded to a power of 2 block since r1.25 in 2009.

Eliminates wasted space when no /usr/mdec/mbr partition
0 information is available.

'-b' becomes available to architectures other than amd64 and
i386, taking precedence over /usr/mdec/mbr partition 0
information. The latter being present only in macppc and loongson
/usr/mdec/mbr files.
---

diff --git a/sbin/fdisk/mbr.c b/sbin/fdisk/mbr.c
index 67b2eda71df..ac911074f5c 100644
--- a/sbin/fdisk/mbr.c
+++ b/sbin/fdisk/mbr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mbr.c,v 1.111 2021/11/25 15:40:26 krw Exp $	*/
+/*	$OpenBSD: mbr.c,v 1.112 2021/12/01 22:37:30 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -63,8 +63,12 @@ MBR_init(struct mbr *mbr)
 	memset(&bootprt, 0, sizeof(bootprt));
 	disksz = disk.dk_cylinders * spc; /* Use only complete cylinders. */
 
-	memcpy(&dp, &default_dmbr.dmbr_parts[0], sizeof(dp));
-	PRT_parse(&dp, 0, 0, &bootprt);
+	if (disk.dk_bootprt.prt_ns > 0) {
+		bootprt = disk.dk_bootprt;
+	} else {
+		memcpy(&dp, &default_dmbr.dmbr_parts[0], sizeof(dp));
+		PRT_parse(&dp, 0, 0, &bootprt);
+	}
 
 	if (bootprt.prt_ns > 0)
 		obsdprt.prt_bs = bootprt.prt_bs + bootprt.prt_ns;
@@ -73,17 +77,6 @@ MBR_init(struct mbr *mbr)
 	else
 		obsdprt.prt_bs = 1;
 
-#if defined(__powerpc__) || defined(__mips__)
-	/* Now fix up for the MS-DOS boot partition on PowerPC/MIPS. */
-	if (obsdprt.prt_bs % spc != 0)
-		obsdprt.prt_bs += spc - (obsdprt.prt_bs % spc);
-#else
-	if (disk.dk_bootprt.prt_ns > 0) {
-		bootprt = disk.dk_bootprt;
-		obsdprt.prt_bs = bootprt.prt_bs + bootprt.prt_ns;
-	}
-#endif
-
 	/* Start OpenBSD MBR partition on a power of 2 block number. */
 	daddr = 1;
 	while (daddr < DL_SECTOBLK(&dl, obsdprt.prt_bs))