0046-docs-Document-the-cutmem-command.patch 2.6 KB

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  1. From f05e79a0143beb2d9a482a3ebf4fe0ce76778122 Mon Sep 17 00:00:00 2001
  2. From: Javier Martinez Canillas <javierm@redhat.com>
  3. Date: Sat, 7 Nov 2020 01:03:18 +0100
  4. Subject: [PATCH] docs: Document the cutmem command
  5. The command is not present in the docs/grub.texi user documentation.
  6. Reported-by: Daniel Kiper <daniel.kiper@oracle.com>
  7. Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
  8. Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
  9. Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
  10. Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
  11. ---
  12. docs/grub.texi | 21 +++++++++++++++++++++
  13. 1 file changed, 21 insertions(+)
  14. diff --git a/docs/grub.texi b/docs/grub.texi
  15. index 79f58c5..8518cc0 100644
  16. --- a/docs/grub.texi
  17. +++ b/docs/grub.texi
  18. @@ -3892,6 +3892,7 @@ you forget a command, you can run the command @command{help}
  19. * cpuid:: Check for CPU features
  20. * crc:: Compute or check CRC32 checksums
  21. * cryptomount:: Mount a crypto device
  22. +* cutmem:: Remove memory regions
  23. * date:: Display or set current date and time
  24. * devicetree:: Load a device tree blob
  25. * distrust:: Remove a pubkey from trusted keys
  26. @@ -4051,6 +4052,8 @@ this page is to be filtered. This syntax makes it easy to represent patterns
  27. that are often result of memory damage, due to physical distribution of memory
  28. cells.
  29. +The command is similar to @command{cutmem} command.
  30. +
  31. Note: The command is not allowed when lockdown is enforced (@pxref{Lockdown}).
  32. This prevents removing EFI memory regions to potentially subvert the
  33. security mechanisms provided by the UEFI secure boot.
  34. @@ -4214,6 +4217,24 @@ GRUB suports devices encrypted using LUKS and geli. Note that necessary modules
  35. be used.
  36. @end deffn
  37. +@node cutmem
  38. +@subsection cutmem
  39. +
  40. +@deffn Command cutmem from[K|M|G] to[K|M|G]
  41. +Remove any memory regions in specified range.
  42. +@end deffn
  43. +
  44. +This command notifies the memory manager that specified regions of RAM ought to
  45. +be filtered out. This remains in effect after a payload kernel has been loaded
  46. +by GRUB, as long as the loaded kernel obtains its memory map from GRUB. Kernels
  47. +that support this include Linux, GNU Mach, the kernel of FreeBSD and Multiboot
  48. +kernels in general.
  49. +
  50. +The command is similar to @command{badram} command.
  51. +
  52. +Note: The command is not allowed when lockdown is enforced (@pxref{Lockdown}).
  53. + This prevents removing EFI memory regions to potentially subvert the
  54. + security mechanisms provided by the UEFI secure boot.
  55. @node date
  56. @subsection date
  57. --
  58. 2.14.2