Package: efibootmgr Version: 0.5.4-6 Severity: normal Tags: patch User: [email protected] Usertags: origin-ubuntu ubuntu-patch saucy
In https://bugs.launchpad.net/bugs/1065261, I got a report that 'efibootmgr -w' overwrites an existing unique MBR signature. This is contrary to its documentation, which says "write unique sig to MBR if needed", and to the ChangeLog entry that introduced it, which said: - Added test for non-zero signature on MBR-style disks, and new -w flag to write a unique signature to the disk if so. This could be resolved either way: by correcting the documentation or by correcting the code. However, overwriting existing unique MBR signatures breaks Windows installations on the same disk, and the UEFI specification says of this field that it should be set by the OS rather than by the firmware. To satisfy all the requirements here, we want a way to set an MBR signature if it is not already non-zero. grub-install uses the -w option to achieve this, believing the documentation, and if the documentation were changed to match the code then grub-install would have to grow some quite complex code to do all the MBR handling itself. It seems a far superior approach to change efibootmgr's code instead. * Fix implementation of -w option to match documentation by leaving an existing unique MBR signature intact (LP: #1065261). diff -Nru efibootmgr-0.5.4/debian/patches/series efibootmgr-0.5.4/debian/patches/series --- efibootmgr-0.5.4/debian/patches/series 2013-01-23 17:30:38.000000000 +0000 +++ efibootmgr-0.5.4/debian/patches/series 2013-02-01 15:50:25.000000000 +0000 @@ -1,3 +1,4 @@ ldflags.patch docbook-fixes.patch efibootmgr-0.5.4-support-4k-sectors.patch +w-keep-existing-mbr-signature.patch diff -Nru efibootmgr-0.5.4/debian/patches/w-keep-existing-mbr-signature.patch efibootmgr-0.5.4/debian/patches/w-keep-existing-mbr-signature.patch --- efibootmgr-0.5.4/debian/patches/w-keep-existing-mbr-signature.patch 1970-01-01 01:00:00.000000000 +0100 +++ efibootmgr-0.5.4/debian/patches/w-keep-existing-mbr-signature.patch 2013-02-01 15:51:44.000000000 +0000 @@ -0,0 +1,20 @@ +Description: Fix -w option to leave an existing unique MBR signature intact + This makes the implementation match the documentation. +Author: Colin Watson <[email protected]> +Bug-Ubuntu: https://bugs.launchpad.net/bugs/1065261 +Forwarded: no +Last-Update: 2013-02-01 + +Index: b/src/lib/disk.c +=================================================================== +--- a/src/lib/disk.c ++++ b/src/lib/disk.c +@@ -352,7 +352,7 @@ + printf("******************************************************\n\n"); + + } +- else if (opts.write_signature) { ++ else if (!mbr->unique_mbr_signature && opts.write_signature) { + + /* MBR Signatures must be unique for the + EFI Boot Manager Thanks, -- Colin Watson [[email protected]] -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
