grub: badram
16.3.6 badram
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-- Command: badram addr,mask[,addr,mask...]
Filter out bad RAM.
This command notifies the memory manager that specified regions of
RAM ought to be filtered out (usually, because they're damaged).
This remains in effect after a payload kernel has been loaded by
GRUB, as long as the loaded kernel obtains its memory map from
GRUB. Kernels that support this include Linux, GNU Mach, the kernel
of FreeBSD and Multiboot kernels in general.
Syntax is the same as provided by the Memtest86+ utility
(http://www.memtest.org/): a list of address/mask pairs. Given a
page-aligned address and a base address / mask pair, if all the
bits of the page-aligned address that are enabled by the mask match
with the base address, it means this page is to be filtered. This
syntax makes it easy to represent patterns that are often result of
memory damage, due to physical distribution of memory cells.
The command is similar to 'cutmem' command.
Note: The command is not allowed when lockdown is enforced (⇒
Lockdown). This prevents removing EFI memory regions to
potentially subvert the security mechanisms provided by the UEFI
secure boot.
Info Catalog
grub: background_image
grub: Command-line and menu entry commands
grub: blocklist