Pull request #106: Recommend usage of partition type GUIDs to find firmware (Heinrich)
Comments in U-Boot mention looking for the partition, but in practice use sector number or MBR partition type or number (not for GPT). Heinrich aiming at creating image booting on multiple platforms (similar to André's Single boot image for SBCs at FOSDEM).
Heinrich: backwards compatibility problem?
Etienne: firmware == UEFI firmware? Could apply to U-Boot SPL loading U-Boot proper. Could apply to ROM.
Ilias: on eMMC, use boot partition.
The way U-Boot SPL finds U-Boot proper can be customised, this is a config option not devicetree. No config option to use a GUID yet. Patch sent to U-Boot by Heinrich.
Ilias: ask more board/SoC vendors? Also, do they care about GPT at all?
Start an informative list of known PartitionTypeGUIDs in EBBR, somewhere. Start with ESP, Arm firmware A/B update, Linux, Windows...
Even GPT partition types have a limit of 128; better use a file on the ESP.