Package: os-prober Version: 1.57 Severity: important Dear Maintainer,
* What led up to the situation? Running update-grub on a Lenovo E530 with Windows 8 (UEFI System) the wrong grub.cfg entry: menuentry 'Windows 8 (loader) (on /dev/sda4)' --class windows --class os $menuentry_id_option 'osprober-chain-168269338269188F' { insmod part_gpt insmod ntfs set root='hd0,gpt4' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt4 --hint-efi=hd0,gpt4 --hint-baremetal=ahci0,gpt4 168269338269188F else search --no-floppy --fs-uuid --set=root 168269338269188F fi drivemap -s (hd0) ${root} chainloader +1 this tries to chainload windows directly instead of using the efi boot code. * What exactly did you do (or not do) that was effective (or ineffective)? update-grub finds Windows in the correct partition. Yet Windows is no more started from it's partition but from the EFI boot code. This code resides in the efi partition (dev/sda2 on the Lenovo) at /EFI/Microsoft/Boot/bootmgfw.efi More detailed: It seems on the Lenovo (and all UEFI systems?) Windows is not anymore booted through the nt loader but through an efi boot loader residing in the efi partition. So trying to chainload to the windows partition will fail. Instead the efi boot loader must be chainloaded. The os-prober seems to be unaware of this change of behavior on uefi systems and adds a non-efi entry (see above) A working grub entry would be (this is from an OpenSuSE install): menuentry 'Windows Boot Manager (auf /dev/sda2)' --class windows --class os $menuentry_id_option 'osprober-efi-F064-7203' { insmod part_gpt insmod fat set root='hd0,gpt2' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2 F064-7203 else search --no-floppy --fs-uuid --set=root F064-7203 fi chainloader /EFI/Microsoft/Boot/bootmgfw.efi } main difference is use of the efi partition instead the windows partition, and use of bootmgfw.efi chainload instead of the "old style" windows chainload. -- System Information: Debian Release: 7.0 APT prefers testing-updates APT policy: (500, 'testing-updates'), (500, 'testing'), (500, 'stable'), (1, 'experimental') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 3.8-trunk-amd64 (SMP w/8 CPU cores) Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Versions of packages os-prober depends on: ii libc6 2.13-38 os-prober recommends no packages. os-prober suggests no packages. -- no debconf information -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org