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/include/part_efi.h b/include/part_efi.h
index 1929e44..c68529b 100644
--- a/include/part_efi.h
+++ b/include/part_efi.h
@@ -56,6 +56,9 @@
#define PARTITION_LINUX_LVM_GUID \
EFI_GUID( 0xe6d6d379, 0xf507, 0x44c2, \
0xa2, 0x3c, 0x23, 0x8f, 0x2a, 0x3d, 0xf9, 0x28)
+#define PARTITION_U_BOOT_ENVIRONMENT \
+ EFI_GUID( 0x3de21764, 0x95bd, 0x54bd, \
+ 0xa5, 0xc3, 0x4a, 0xbe, 0x78, 0x6f, 0x38, 0xa8)
/* linux/include/efi.h */
typedef u16 efi_char16_t;