Initial support to read GPT partition tables in the kernel, if option GPT.

Contributed by Markus Mueller; code based upon Bitrig's GPT support, with
stricter GPT structures validation and support for alternate header places.

ok deraadt@ jsing@ krw@

2 files changed, 9 insertions, 2 deletions

diff --git a/sys/arch/i386/conf/GENERIC b/sys/arch/i386/conf/GENERIC
index 87300279bb4..76556799dfb 100644
--- a/sys/arch/i386/conf/GENERIC
+++ b/sys/arch/i386/conf/GENERIC
@@ -1,4 +1,4 @@
-#	$OpenBSD: GENERIC,v 1.780 2014/07/12 21:56:56 tedu Exp $
+#	$OpenBSD: GENERIC,v 1.781 2014/07/13 15:32:28 miod Exp $
 #
 # For further information on compiling OpenBSD kernels, see the config(8)
 # man page.
@@ -27,6 +27,7 @@ option		MTRR		# CPU memory range attributes control
 option		COMPAT_LINUX	# binary compatibility with Linux
 
 #option		PROCFS		# /proc, currently broken
+option		GPT		# GPT partition table support
 option		NTFS		# NTFS support
 option		HIBERNATE	# Hibernate support
 
diff --git a/sys/arch/i386/i386/disksubr.c b/sys/arch/i386/i386/disksubr.c
index 6da9f77a7bd..a8bf13d7bb0 100644
--- a/sys/arch/i386/i386/disksubr.c
+++ b/sys/arch/i386/i386/disksubr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: disksubr.c,v 1.106 2014/06/15 11:43:24 sf Exp $	*/
+/*	$OpenBSD: disksubr.c,v 1.107 2014/07/13 15:32:28 miod Exp $	*/
 /*	$NetBSD: disksubr.c,v 1.21 1996/05/03 19:42:03 christos Exp $	*/
 
 /*
@@ -93,6 +93,12 @@ readdisklabel(dev_t dev, void (*strat)(struct buf *),
 	bp = geteblk((int)lp->d_secsize);
 	bp->b_dev = dev;
 
+#if defined(GPT)
+	error = readgptlabel(bp, strat, lp, NULL, spoofonly);
+	if (error == 0)
+		goto done;
+#endif
+
 	error = readdoslabel(bp, strat, lp, NULL, spoofonly);
 	if (error == 0)
 		goto done;