Updated grub packages that fix several bugs and add two enhancements are now available for Red Hat Enterprise Linux 6.
The GRUB utility is a powerful boot loader, which can load a wide variety of operating systems.
- When the BIOS was set to Unified Extensible Firmware Interface (UEFI) mode, all legacy option ROMs in the setup were disabled, and the grub.efi utility was loaded, an attempt to access the network with the NET0 protocol was not successful and the "nd" root command did not work. This bug has been fixed and GRUB works correctly in this situation.
- Previously, the GRUB utility did not scan for KVM virtio disks when creating a device map. Consequently, these disks were not added to this map. This bug has been fixed and GRUB now scans for vd* devices located in the /dev/ directory, so virtio disks are added to a device map as expected.
- The GRUB utility did not pass high order address bits for the Extensible Firmware Interface (EFI) memory map and system table high order bits. As a consequence, the EFI system map and memory map did not work correctly on computers with RAM bigger then 4 GB. This bug has been fixed by passing high order address bits, so that grub works properly in the described scenario.
- When symbolic links in the /dev/mapper/ directory were resolved to the original file, this file did not match proper file entry in the device.map file. Consequently, the grub-install package failed and an error message was returned. With this update, symbolic links are now prevented to resolve in the /dev/mapper/ directory. As a result, grub-install proceeds as expected.
- Due to an error in the underlying source code, an incorrect attempt to dereference a NULL pointer could previously cause GRUB to terminate unexpectedly. This update corrects the underlying source code to prevent this error so that GRUB no longer crashes.
- This enhancement includes support for IPV6 UEFI 2.3.1 netboot, which was previously missing.
- With this update, the users can use EFI boot partition as a root partition, which can be specified in the grub.conf file. As a consequence, the users do not have to specify particular drive, but can use the one specified in the EFI boot manager.
All users of GRUB are advised to upgrade to these updated packages, which fix these bugs and add these enhancements.