Align rootfs partition id with freedesktop GUIDs on all platforms

[lool]

Hi,

In current qcom-ptool, these platforms define an ESP partition called "efi" (using efi.bin) using the proper GUID (c12a7328-f81f-11d2-ba4b-00a0c93ec93b) for EFI System Partition per The Discoverable Partitions Specification (DPS):

• platforms/qcm6490/partitions.conf
• platforms/qrb4210-rb2/partitions.conf
• platforms/qcs9100/partitions.conf
• platforms/qrb2210-rb1/partitions.conf

However while all of these platforms define a root partition called "rootfs" (using rootfs.img), only these two platforms use the correct GUID (b921b045-1df0-41c3-af44-4c6f280d3fae) for Root Partition (64-bit ARM/AArch64):

• platforms/qcm6490/partitions.conf
• platforms/qcs9100/partitions.conf

While these two use a GUID not defined in the DPS (1B81E7E6-F50D-419B-A739-2AEEF8DA3335):

• platforms/qrb4210-rb2/partitions.conf
• platforms/qrb2210-rb1/partitions.conf

Notably, I don't think systemd recognizes this GUID.

[lool]

I suspect this is a remnant of these platforms shipping without an UEFI capable firmware.

[ndechesne]

We imported the partition.conf file for RB1 from db-boot-tool from Linaro, and that GUID comes from here:
https://git.codelinaro.org/linaro/qcomlt/db-boot-tools/-/commit/fb9032ce65d72cc0f00a5d6de727c979fedc1036
When we converted the Android partition config to Linux with ESP and rootfs. This GUID was the one used for the Android userdata partition. So this is a real bug. Do you want to update it?

[lool]

Is there any known meaning to the GUID? Any boot firmware or other tool that might count on it?

[lool]

Not sure if this is legit, but this random repo lists it as "userdata" partition:
https://github.com/HelllGuest/Qualcomm_tools/blob/master/gpt_parser-for-xml.py#L473

And this one as Android user data:
https://gitlab.tails.boum.org/tails/gdisk/-/blob/tails/bookworm/parttypes.cc?ref_type=heads#L350

[ndechesne]

Is there any known meaning to the GUID? Any boot firmware or other tool that might count on it?

yes. The GUIDs are used to 'find' the partition. eg. the ROM CODE (PBL) will find the first stage bootloader (XBL) by looking for the GUID DEA0BA2C-CBDD-4805-B4F9-F428251C3E98. And it's the same thing for each stage of the boot.

[lool]

Is there any known meaning to the GUID? Any boot firmware or other tool that might count on it?

yes. The GUIDs are used to 'find' the partition. eg. the ROM CODE (PBL) will find the first stage bootloader (XBL) by looking for the GUID DEA0BA2C-CBDD-4805-B4F9-F428251C3E98. And it's the same thing for each stage of the boot.

So which part might be break by changing the Android userdata partition? I guess this highlights that this is also OS specific, so really the partitions files here might be for a Linux boot, a Yocto A/B boot, or an Android A/B boot.

We should still be consistent and use the right GUIDs when that makes sense, but I suspect we'll maintain partition files in OS-specific repositories.

[ndechesne]

So which part might be break by changing the Android userdata partition? I guess this highlights that this is also OS specific, so really the partitions files here might be for a Linux boot, a Yocto A/B boot, or an Android A/B boot.

Using the userdata GUID was a 'bug'. For our rootfs partition we need to use the correct GUID (b921b045-1df0-41c3-af44-4c6f280d3fae) for Root Partition (64-bit ARM/AArch64). It won't break anything.

[ricardosalveti]

Yeah, changing for the rootfs only won't really affect anything here.