SWUpdate with unified-kernel using UUID in the kernel command line

SWUpdate with unified-kernel using UUID in the kernel command line

[Shivanand.Kunijadar]

Hi CIP-team, 

I'm trying to use UUID in the kernel command line for selecting the boot target(rootfs) with unified-kernel image.  
Check the below details on how UUID is used to switch the partitions and let me know what is the advantage of the initramfs script approach over UUID?

* Use filesystem UUID to specify the boot target (rootfs)
* UUID is generated for each filesystem and its value changes every release.
* Each unified kernel image is always generated with root=UUID=(The UUID of corresponding filesystem) in its cmdline and .swu includes the pair of unified kernel and rootfs.
* Install the update image using raw update type (i.e. block level).

Example:

Before update, Active partition: ROOTFS-A(mmcblk1p4):
sudo blkid
/dev/mmcblk1p4: LABEL="ROOTFS1" UUID="U1" TYPE="ext4" PARTLABEL="ROOTFS1" PARTUUID="PARTUUID1"
/dev/mmcblk1p5: LABEL="ROOTFS2" UUID="U0" TYPE="ext4" PARTLABEL="ROOTFS2" PARTUUID="PARTUUID2"

While building .swu
.swu includes...
a partition image (for ROOTFS-X) which UUID is U2
a unified kernel which cmdline includes root=UUID=U2

While installing the .swu for ROOTFS-B:
Unified kernel is installed to BOOT-B(mmcblk1p2)
The partition image is installed to ROOTFS-B(mmcblk1p5)

After update, Active partition: ROOTFS-B(mmcblk1p5):
sudo blkid
/dev/mmcblk1p4: LABEL="ROOTFS1" UUID="U1" TYPE="ext4" PARTLABEL="ROOTFS1" PARTUUID="PARTUUID1"
/dev/mmcblk1p5: LABEL="ROOTFS2" UUID="U2" TYPE="ext4" PARTLABEL="ROOTFS2" PARTUUID="PARTUUID2"

Thanks & Regards
Shivanand K

RE: SWUpdate with unified-kernel using UUID in the kernel command line

[Shivanand.Kunijadar]

Hi CIP-team, 

Any comments on this approach ? 
Let's discuss this topic in the today's CIP core meeting.

Thanks & Regards
Shivanand K 

-----Original Message-----
From: kunijadar shivanand(ＴＳＩＰ TMIEC ODG Porting) 
Sent: 27 January 2023 12:50
To: cip-dev@lists.cip-project.org
Cc: jan.kiszka@siemens.com; 38A5323E673042E40E350B6BD8E7D4A7 <kazuhiro3.hayashi@toshiba.co.jp>; dinesh kumar(TSIP TMIEC ODG Porting) <dinesh.kumar@toshiba-tsip.com>; pyla venkata(TSIP TMIEC ODG Porting) <Venkata.Pyla@toshiba-tsip.com>
Subject: SWUpdate with unified-kernel using UUID in the kernel command line

Hi CIP-team, 

I'm trying to use UUID in the kernel command line for selecting the boot target(rootfs) with unified-kernel image.  
Check the below details on how UUID is used to switch the partitions and let me know what is the advantage of the initramfs script approach over UUID?

* Use filesystem UUID to specify the boot target (rootfs)
* UUID is generated for each filesystem and its value changes every release.
* Each unified kernel image is always generated with root=UUID=(The UUID of corresponding filesystem) in its cmdline and .swu includes the pair of unified kernel and rootfs.
* Install the update image using raw update type (i.e. block level).

Example:

Before update, Active partition: ROOTFS-A(mmcblk1p4):
sudo blkid
/dev/mmcblk1p4: LABEL="ROOTFS1" UUID="U1" TYPE="ext4" PARTLABEL="ROOTFS1" PARTUUID="PARTUUID1"
/dev/mmcblk1p5: LABEL="ROOTFS2" UUID="U0" TYPE="ext4" PARTLABEL="ROOTFS2" PARTUUID="PARTUUID2"

While building .swu
.swu includes...
a partition image (for ROOTFS-X) which UUID is U2 a unified kernel which cmdline includes root=UUID=U2

While installing the .swu for ROOTFS-B:
Unified kernel is installed to BOOT-B(mmcblk1p2) The partition image is installed to ROOTFS-B(mmcblk1p5)

After update, Active partition: ROOTFS-B(mmcblk1p5):
sudo blkid
/dev/mmcblk1p4: LABEL="ROOTFS1" UUID="U1" TYPE="ext4" PARTLABEL="ROOTFS1" PARTUUID="PARTUUID1"
/dev/mmcblk1p5: LABEL="ROOTFS2" UUID="U2" TYPE="ext4" PARTLABEL="ROOTFS2" PARTUUID="PARTUUID2"

Thanks & Regards
Shivanand K

Re: SWUpdate with unified-kernel using UUID in the kernel command line

[Jan Kiszka]

On 27.01.23 08:19, Shivanand.Kunijadar@toshiba-tsip.com wrote:
> Hi CIP-team, 
> 
> I'm trying to use UUID in the kernel command line for selecting the boot target(rootfs) with unified-kernel image.  
> Check the below details on how UUID is used to switch the partitions and let me know what is the advantage of the initramfs script approach over UUID?
> 
> * Use filesystem UUID to specify the boot target (rootfs)

We considered using filesystem UUIDs for selecting the rootfs by the UKI
 (in the absence for dm-verity-based peering), but not all filesystems
come with this feature. Therefore, isar-cip-core implements a mechanism
that is independent of the filesystem type.

HTH,
Jan

> * UUID is generated for each filesystem and its value changes every release.
> * Each unified kernel image is always generated with root=UUID=(The UUID of corresponding filesystem) in its cmdline and .swu includes the pair of unified kernel and rootfs.
> * Install the update image using raw update type (i.e. block level).
> 
> Example:
> 
> Before update, Active partition: ROOTFS-A(mmcblk1p4):
> sudo blkid
> /dev/mmcblk1p4: LABEL="ROOTFS1" UUID="U1" TYPE="ext4" PARTLABEL="ROOTFS1" PARTUUID="PARTUUID1"
> /dev/mmcblk1p5: LABEL="ROOTFS2" UUID="U0" TYPE="ext4" PARTLABEL="ROOTFS2" PARTUUID="PARTUUID2"
> 
> While building .swu
> .swu includes...
> a partition image (for ROOTFS-X) which UUID is U2
> a unified kernel which cmdline includes root=UUID=U2
> 
> While installing the .swu for ROOTFS-B:
> Unified kernel is installed to BOOT-B(mmcblk1p2)
> The partition image is installed to ROOTFS-B(mmcblk1p5)
> 
> After update, Active partition: ROOTFS-B(mmcblk1p5):
> sudo blkid
> /dev/mmcblk1p4: LABEL="ROOTFS1" UUID="U1" TYPE="ext4" PARTLABEL="ROOTFS1" PARTUUID="PARTUUID1"
> /dev/mmcblk1p5: LABEL="ROOTFS2" UUID="U2" TYPE="ext4" PARTLABEL="ROOTFS2" PARTUUID="PARTUUID2"
> 
> Thanks & Regards
> Shivanand K
> 

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