6a34fdb76a
When booting on an ARMv8 core that implements either CTR.IDC or CTR.DIC (indicating that some of the cache maintenance operations can be removed when dealing with I/D-cache coherency, GRUB dies with a "Unsupported cache type 0x........" message. This is pretty likely to happen when running in a virtual machine hosted on an arm64 machine (I've triggered it on a system built around a bunch of Cortex-A55 cores, which implements CTR.IDC). It turns out that the way GRUB deals with the CTR register is a bit harsh for anything from ARMv7 onwards. The layout of the register is backward compatible, meaning that nothing that gets added is allowed to break earlier behaviour. In this case, ignoring IDC is completely fine, and only results in unnecessary cache maintenance. We can thus avoid being paranoid, and align the 32bit behaviour with its 64bit equivalent. This patch has the added benefit that it gets rid of a (gnu-specific) case range too. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Leif Lindholm <leif@nuviainc.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This is GRUB 2, the second version of the GRand Unified Bootloader. GRUB 2 is rewritten from scratch to make GNU GRUB cleaner, safer, more robust, more powerful, and more portable. See the file NEWS for a description of recent changes to GRUB 2. See the file INSTALL for instructions on how to build and install the GRUB 2 data and program files. Please visit the official web page of GRUB 2, for more information. The URL is <http://www.gnu.org/software/grub/grub.html>. More extensive documentation is available in the Info manual, accessible using 'info grub' after building and installing GRUB 2. There are a number of important user-visible differences from the first version of GRUB, now known as GRUB Legacy. For a summary, please see: info grub Introduction 'Changes from GRUB Legacy'