[PATCH v2] Documentation: x86: boot: reserve type_of_loader=13 for barebox

[Ahmad Fatoum]

barebox[1], a bootloader for mostly ARM and MIPS embedded systems,
can also be built as EFI payload for x86[2] to provide redundant
power-fail safe, watchdog-supervised boot up.

Since its v2015.09.0 release, it has been booting Linux on x86 with
type_of_loader=0xff[3]. Reserve 13, the next free id, so that can be
used instead in the future.

[1]: https://www.barebox.org/
[2]: https://www.barebox.org/doc/latest/boards/efi.html
[3]: https://elixir.bootlin.com/barebox/v2022.09.0/source/common/efi/payload/image.c#L217

Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
---
v1 -> v2:
  - elaborate on what barebox is and add some links to commit
    message (Boris)

v1 was here:
https://lore.kernel.org/all/20220513143039.2065756-1-a.fatoum@xxxxxxxxxxxxxx/
---
 Documentation/x86/boot.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst
index 894a19897005..240d084782a6 100644
--- a/Documentation/x86/boot.rst
+++ b/Documentation/x86/boot.rst
@@ -455,6 +455,7 @@ Protocol:	2.00+
 	11 Minimal Linux Bootloader
 	   <http://sebastian-plotz.blogspot.de>
 	12 OVMF UEFI virtualization stack
+	13 barebox
 	== =======================================
 
   Please contact <hpa@xxxxxxxxx> if you need a bootloader ID value assigned.
-- 
2.30.2