From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id F11251A0FFE for ; Wed, 1 Jul 2015 04:57:57 +1000 (AEST) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 7886514030A for ; Wed, 1 Jul 2015 04:57:56 +1000 (AEST) Date: Tue, 30 Jun 2015 20:57:45 +0200 From: Thomas Huth To: Nikunj A Dadhania Cc: aik@ozlabs.ru, linuxppc-dev@ozlabs.org, dvaleev@suse.com Subject: Re: [PATCH SLOF v3 5/5] disk-label: add support for booting from GPT FAT partition Message-ID: <20150630205745.76a4c25e@thh440s> In-Reply-To: <87h9ppz8nl.fsf@linux.vnet.ibm.com> References: <1435662081-4293-1-git-send-email-nikunj@linux.vnet.ibm.com> <1435662081-4293-6-git-send-email-nikunj@linux.vnet.ibm.com> <20150630132834.16643eb5@thh440s> <87h9ppz8nl.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 30 Jun 2015 17:54:14 +0530 Nikunj A Dadhania wrote: > > disk-label: add support for booting from GPT FAT partition > > For a GPT+LVM combination disk, older bootloader that does not support > LVM, cannot load kernel from LVM. > > The patch adds support to read from BASIC_DATA UUID partitions for the > case that the OS installer has installed the CHRP-BOOT config on a FAT > file system. > > Makes GPT detection robust > * Fix bug in seek-pos updation code > * Check for Protective MBR Magic > * Check for valid GPT Signature > * Boundary check for allocated block size before reading into the > buffer > > Signed-off-by: Nikunj A Dadhania > > diff --git a/slof/fs/packages/disk-label.fs b/slof/fs/packages/disk-label.fs > index 347dc5d..fa5df27 100644 > --- a/slof/fs/packages/disk-label.fs > +++ b/slof/fs/packages/disk-label.fs > @@ -179,7 +179,8 @@ CONSTANT /gpt-part-entry > \ This word returns true if the currently loaded disk-buf has _NO_ GPT partition id > : no-gpt? ( -- true|false ) > 0 read-disk-buf > - 1 partition>part-entry part-entry>id c@ ee <> > + 1 partition>part-entry part-entry>id c@ ee <> IF true EXIT THEN > + disk-buf mbr>magic w@-le aa55 <> > ; > > : pc-extended-partition? ( part-entry-addr -- true|false ) > @@ -267,7 +268,10 @@ CONSTANT /gpt-part-entry > > : try-dos-partition ( -- okay? ) > \ Read partition table and check magic. > - no-mbr? IF cr ." No DOS disk-label found." cr false EXIT THEN > + no-mbr? IF > + debug-disk-label? IF cr ." No DOS disk-label found." cr THEN > + false EXIT > + THEN > > count-dos-logical-partitions TO dos-logical-partitions > > @@ -377,31 +381,85 @@ AA268B49521E5A8B CONSTANT GPT-PREP-PARTITION-4 > 8 + x@ GPT-PREP-PARTITION-4 = > ; > > -: load-from-gpt-prep-partition ( addr -- size ) > - no-gpt? IF drop false EXIT THEN > - debug-disk-label? IF > - cr ." GPT partition found " cr > - THEN > - 1 read-disk-buf disk-buf gpt>part-entry-lba l@-le > +\ Check for GPT MSFT BASIC DATA GUID - fat based > +EBD0A0A2 CONSTANT GPT-BASIC-DATA-PARTITION-1 > +B9E5 CONSTANT GPT-BASIC-DATA-PARTITION-2 > +4433 CONSTANT GPT-BASIC-DATA-PARTITION-3 > +87C068B6B72699C7 CONSTANT GPT-BASIC-DATA-PARTITION-4 > + > +: gpt-basic-data-partition? ( -- true|false ) > + disk-buf gpt-part-entry>part-type-guid > + dup l@-le GPT-BASIC-DATA-PARTITION-1 <> IF drop false EXIT THEN > + dup 4 + w@-le GPT-BASIC-DATA-PARTITION-2 <> IF drop false EXIT THEN > + dup 6 + w@-le GPT-BASIC-DATA-PARTITION-3 <> IF drop false EXIT THEN > + 8 + x@ GPT-BASIC-DATA-PARTITION-4 = > +; > + > +\ > +\ GPT Signature > +\ ("EFI PART", 45h 46h 49h 20h 50h 41h 52h 54h) > +\ > +4546492050415254 CONSTANT GPT-SIGNATURE > + > +\ The routine checks whether the protective MBR has GPT ID and then > +\ reads the gpt data from the sector. Also set the seek position and > +\ the partition size used in caller routines. > + > +: get-gpt-partition ( -- true|false ) > + no-gpt? IF false EXIT THEN > + debug-disk-label? IF cr ." GPT partition found " cr THEN > + 1 read-disk-buf > + disk-buf gpt>part-entry-lba x@-le > block-size * to seek-pos > disk-buf gpt>part-entry-size l@-le to gpt-part-size > - disk-buf gpt>num-part-entry l@-le dup 0= IF false EXIT THEN > + gpt-part-size disk-buf-size > IF > + cr ." GPT part size exceeds buffer allocated " cr > + false exit > + THEN > + disk-buf gpt>signature x@ GPT-SIGNATURE = > +; > + > +: load-from-gpt-prep-partition ( addr -- size ) > + get-gpt-partition 0= IF false EXIT THEN > + disk-buf gpt>num-part-entry l@-le dup 0= IF false exit THEN > 1+ 1 ?DO > seek-pos 0 seek drop > disk-buf gpt-part-size read drop gpt-prep-partition? IF > - debug-disk-label? IF > - ." GPT PReP partition found " cr > - THEN > - disk-buf gpt-part-entry>first-lba x@-le > - disk-buf gpt-part-entry>last-lba x@-le > - over - 1+ ( addr offset len ) > - swap ( addr len offset ) > - block-size * to part-offset > - 0 0 seek drop ( addr len ) > - block-size * read ( size ) > + debug-disk-label? IF ." GPT PReP partition found " cr THEN > + disk-buf gpt-part-entry>first-lba x@-le ( addr first-lba ) > + disk-buf gpt-part-entry>last-lba x@-le ( addr first-lba last-lba) > + over - 1+ ( addr first-lba blocks ) > + swap ( addr blocks first-lba ) > + block-size * to part-offset ( addr blocks ) > + 0 0 seek drop ( addr blocks ) > + block-size * read ( size ) > + UNLOOP EXIT > + THEN > + seek-pos gpt-part-size + to seek-pos > + LOOP > + false > +; > + > +: try-gpt-dos-partition ( -- true|false ) > + get-gpt-partition 0= IF false EXIT THEN > + disk-buf gpt>num-part-entry l@-le dup 0= IF false EXIT THEN > + 1+ 1 ?DO > + seek-pos 0 seek drop > + disk-buf gpt-part-size read drop > + gpt-basic-data-partition? IF > + debug-disk-label? IF ." GPT BASIC DATA partition found " cr THEN > + disk-buf gpt-part-entry>first-lba x@-le ( first-lba ) > + dup to part-start ( first-lba ) > + disk-buf gpt-part-entry>last-lba x@-le ( first-lba last-lba ) > + over - 1+ ( first-lba s1 ) > + block-size * to part-size ( first-lba ) > + block-size * to part-offset ( ) > + 0 0 seek drop > + disk-buf block-size read drop > + disk-buf fat-bootblock? ( true|false ) > UNLOOP EXIT > THEN > - seek-pos gpt-part-size i * + to seek-pos > + seek-pos gpt-part-size + to seek-pos > LOOP > false > ; > @@ -491,7 +549,7 @@ AA268B49521E5A8B CONSTANT GPT-PREP-PARTITION-4 > > debug-disk-label? IF ." Trying CHRP boot " .s cr THEN > 1 disk-chrp-boot ! > - dup load-chrp-boot-file ?dup 0 <> IF .s cr nip EXIT THEN > + dup load-chrp-boot-file ?dup 0 <> IF nip EXIT THEN > 0 disk-chrp-boot ! > > debug-disk-label? IF ." Trying GPT boot " .s cr THEN > @@ -591,6 +649,7 @@ AA268B49521E5A8B CONSTANT GPT-PREP-PARTITION-4 > > : try-partitions ( -- found? ) > try-dos-partition IF try-files EXIT THEN > + try-gpt-dos-partition IF try-files EXIT THEN > \ try-iso9660-partition IF try-files EXIT THEN > \ ... more partition types here... > false This version now looks fine to me. Reviewed-by: Thomas Huth