doc/README.gpt: define partition type GUID for U-Boot environment
When setting aside a GPT partition for holding the U-Boot environment,
having a partition type GUID [1] indicating "Linux filesystem" (as
most tools default to) is somewhat misleading - and there's no other
well-known type GUID that is better suited. So to have a canonical
value to put into the type field, define
3de21764-95bd-54bd-a5c3-4abe786f38a8
to mean a partition holding a U-Boot environment.
This is a v5 namespace-name GUID [2], generated [3] from a namespace
of "25cbcde0-8642-47c6-a298-1a3a57cd256b" and name "U-Boot
environment".
Should future type GUIDs be defined in the context of U-Boot, it's
sensible to use that same namespace GUID.
[1] https://en.wikipedia.org/wiki/GUID_Partition_Table#Partition_type_GUIDs
[2] https://en.wikipedia.org/wiki/Universally_unique_identifier#Versions_3_and_5_(namespace_name-based)
[3] https://www.uuidtools.com/v5
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
diff --git a/doc/README.gpt b/doc/README.gpt
index facd7af..9e0d222 100644
--- a/doc/README.gpt
+++ b/doc/README.gpt
@@ -267,6 +267,8 @@
(0657FD6D-A4AB-43C4-84E5-0933C84B4F4F)
"lvm" = PARTITION_LINUX_LVM_GUID
(E6D6D379-F507-44C2-A23C-238F2A3DF928)
+ "u-boot-env" = PARTITION_U_BOOT_ENVIRONMENT
+ (3DE21764-95BD-54BD-A5C3-4ABE786F38A8)
"uuid_disk=...;name=u-boot,size=60MiB,uuid=...;
name=kernel,size=60MiB,uuid=...,type=linux;"