nalika / rpms / grub2

Forked from rpms/grub2 2 years ago
Clone
9723a8
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
9723a8
From: Javier Martinez Canillas <javierm@redhat.com>
9723a8
Date: Sat, 7 Nov 2020 01:03:18 +0100
9723a8
Subject: [PATCH] docs: Document the cutmem command
9723a8
9723a8
The command is not present in the docs/grub.texi user documentation.
9723a8
9723a8
Reported-by: Daniel Kiper <daniel.kiper@oracle.com>
9723a8
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
9723a8
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
9723a8
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
9723a8
---
9723a8
 docs/grub.texi | 21 +++++++++++++++++++++
9723a8
 1 file changed, 21 insertions(+)
9723a8
9723a8
diff --git a/docs/grub.texi b/docs/grub.texi
b71686
index c55452307..314bbeb84 100644
9723a8
--- a/docs/grub.texi
9723a8
+++ b/docs/grub.texi
3efed6
@@ -3942,6 +3942,7 @@ you forget a command, you can run the command @command{help}
9723a8
 * cpuid::                       Check for CPU features
9723a8
 * crc::                         Compute or check CRC32 checksums
9723a8
 * cryptomount::                 Mount a crypto device
9723a8
+* cutmem::                      Remove memory regions
9723a8
 * date::                        Display or set current date and time
9723a8
 * devicetree::                  Load a device tree blob
9723a8
 * distrust::                    Remove a pubkey from trusted keys
3efed6
@@ -4103,6 +4104,8 @@ this page is to be filtered.  This syntax makes it easy to represent patterns
9723a8
 that are often result of memory damage, due to physical distribution of memory
9723a8
 cells.
9723a8
 
9723a8
+The command is similar to @command{cutmem} command.
9723a8
+
9723a8
 Note: The command is not allowed when lockdown is enforced (@pxref{Lockdown}).
9723a8
       This prevents removing EFI memory regions to potentially subvert the
9723a8
       security mechanisms provided by the UEFI secure boot.
3efed6
@@ -4266,6 +4269,24 @@ GRUB suports devices encrypted using LUKS and geli. Note that necessary modules
9723a8
 be used.
9723a8
 @end deffn
9723a8
 
9723a8
+@node cutmem
9723a8
+@subsection cutmem
9723a8
+
9723a8
+@deffn Command cutmem from[K|M|G] to[K|M|G]
9723a8
+Remove any memory regions in specified range.
9723a8
+@end deffn
9723a8
+
9723a8
+This command notifies the memory manager that specified regions of RAM ought to
9723a8
+be filtered out. This remains in effect after a payload kernel has been loaded
9723a8
+by GRUB, as long as the loaded kernel obtains its memory map from GRUB. Kernels
9723a8
+that support this include Linux, GNU Mach, the kernel of FreeBSD and Multiboot
9723a8
+kernels in general.
9723a8
+
9723a8
+The command is similar to @command{badram} command.
9723a8
+
9723a8
+Note: The command is not allowed when lockdown is enforced (@pxref{Lockdown}).
9723a8
+      This prevents removing EFI memory regions to potentially subvert the
9723a8
+      security mechanisms provided by the UEFI secure boot.
9723a8
 
9723a8
 @node date
9723a8
 @subsection date