RAUC kernel update failure (Error:FAT-fs bogus number of FAT structure)

[Rajalakshmi-Ranganathan]

Hi @ejoerns and others,

I'm using meta-rauc (Honister) where I am able to successfully update the rootfs slots using rauc bundle. But I am facing below issue when trying to update kernel. Also I have provided details like partition table, system.conf & bundle recipe file. Please take a look and provide your suggestions.

Error:

rauc --debug install http://10.42.0.2:8080/kernel_update/update-bundle-zynq-generic.raucb
rauc-Message: 12:37:50.434: Debug log domains: 'rauc'
(rauc:872): rauc-DEBUG: 12:37:50.454: install started
(rauc:872): rauc-DEBUG: 12:37:50.455: input bundle: http://10.42.0.2:8080/kernel_update/update-bundle-zynq-generic.raucb
(rauc:872): rauc-DEBUG: 12:37:50.503: Trying to contact rauc service
installing
0% Installing
0% Determining slot states
20% Determining slot states done.
20% Checking bundle
20% Verifying signature
40% Verifying signature done.
40% Checking bundle done.
40% Checking manifest contents
60% Checking manifest contents done.
60% Determining target install group
80% Determining target install group done.
80% Updating slots
80% Checking slot rootfs.1
85% Checking slot rootfs.1 done.
85% Copying image to rootfs.1
90% Copying image to rootfs.1 done.
90% Checking slot kernel.1
95% Checking slot kernel.1 done.
95% Copying image to kernel.1
99% Copying image to kernel.1 done.
FAT-fs (mmcblk0p6): bogus number of FAT structure
99% Updating slots failed.
100% Installing failed.
LastError: Installation error: Error while writing status file: failed to mount slot: failed to run mount: Child process exited with code 32
Installing http://10.42.0.2:8080/kernel_update/update-bundle-zynq-generic.raucb failed

My Disk Partition Table:

Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 2048 206847 204800 100M c W95 FAT32 (LBA) ======> BOOT
/dev/mmcblk0p2 206848 2303999 2097152 1G c W95 FAT32 (LBA) ======> BOOTENV
/dev/mmcblk0p3 2304000 30930943 28626944 13.7G 5 Extended
/dev/mmcblk0p5 2306048 2510847 204800 100M c W95 FAT32 (LBA) =====> Kernel.0 Image
/dev/mmcblk0p6 2512896 2717695 204800 100M c W95 FAT32 (LBA) =====> Kernel.1 Image
/dev/mmcblk0p7 2719744 15302655 12582912 6G 83 Linux =====> Rootfs.0 files
/dev/mmcblk0p8 15304704 30930943 15626240 7.5G 83 Linux =====> Rootfs.1 files

RAUC system.conf:

[system]
compatible=RAUC Fw Update
bootloader=uboot
bundle-formats=verity
max-bundle-download-size=209715200

[keyring]
path=/etc/rauc/ca.cert.pem

[slot.rootfs.0]
device=/dev/mmcblk0p7
type=ext4
bootname=system0

[slot.rootfs.1]
device=/dev/mmcblk0p8
type=ext4
bootname=system1

[slot.kernel.0]
device=/dev/mmcblk0p5
type=vfat
parent=rootfs.0

[slot.kernel.1]
device=/dev/mmcblk0p6
type=vfat
parent=rootfs.1

My Bundle Recipe:

DESCRIPTION = "RAUC bundle generator"

LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"

inherit bundle

RAUC_BUNDLE_FORMAT = "verity"

RAUC_BUNDLE_COMPATIBLE = "RAUC Fw Update"
RAUC_BUNDLE_VERSION = "v20240326"
RAUC_BUNDLE_DESCRIPTION = "RAUC Update Bundle"

RAUC_BUNDLE_SLOTS = "rootfs kernel"
RAUC_SLOT_rootfs = "petalinux-image-minimal"
RAUC_SLOT_rootfs[fstype] = "tar.gz"

RAUC_SLOT_kernel = "linux-xlnx"
RAUC_SLOT_kernel[type] = "file"
RAUC_SLOT_kernel[file] = "fitImage"

RAUC_KEY_FILE = "${THISDIR}/files/development-1.key.pem"
RAUC_CERT_FILE = "${THISDIR}/files/development-1.cert.pem"

[jluebbe]

You've configured the the kernel.* slots as type vfat and have not configured a shared data directory, which means that RAUC will try to mount them to store slot status information. But, because you write the FIT image directory to that slot, it doesn't contain a FAT file system and mounting fails.

I'd suggest to both:

• configure a data directory on a shared partition
• use type raw for the kernel slots

[Rajalakshmi-Ranganathan]

Thanks a lot @jluebbe for the response.

I'm using Rauc version 1.7 where data-directory key is not available. However I used statusfile key and able to see bundle installation completed successfully.

But once I reboot, kernel is unable to boot. After debugging further, I noticed that kernel.1 slot partition mmcblk0p6 got corrupted after "rauc update". Please find the log, system.conf and mount output as below and kindly help to resolve the partition corruption issue.

Rauc update result log:

:~$ rauc --debug install http://10.42.0.2:8080/kernel_update/update-bundle-zynq-generic.raucb
rauc-Message: 12:51:05.871: Debug log domains: 'all'
(rauc:989): rauc-DEBUG: 12:51:05.881: install started
(rauc:989): rauc-DEBUG: 12:51:05.882: input bundle: http://10.42.0.2:8080/kernel_update/update-bundle-zynq-generic.raucb
(rauc:989): rauc-DEBUG: 12:51:05.899: Trying to contact rauc service
installing
0% Installing
0% Determining slot states
20% Determining slot states done.
20% Checking bundle
20% Verifying signature
40% Verifying signature done.
40% Checking bundle done.
40% Checking manifest contents
60% Checking manifest contents done.
60% Determining target install group
80% Determining target install group done.
80% Updating slots
80% Checking slot rootfs.1
85% Checking slot rootfs.1 done.
85% Copying image to rootfs.1
90% Copying image to rootfs.1 done.
90% Checking slot kernel.1
95% Checking slot kernel.1 done.
95% Copying image to kernel.1
99% Copying image to kernel.1 done.
99% Updating slots done.
100% Installing done.
Installing http://10.42.0.2:8080/kernel_update/update-bundle-zynq-generic.raucb succeeded

system.conf:

[system]
compatible=RAUC Fw Update
bootloader=uboot
bundle-formats=verity
max-bundle-download-size=209715200
statusfile=/media/central-status.raucs

[keyring]
path=/etc/rauc/ca.cert.pem

[slot.rootfs.0]
device=/dev/mmcblk0p7
type=ext4
bootname=system0

[slot.rootfs.1]
device=/dev/mmcblk0p8
type=ext4
bootname=system1

[slot.kernel.0]
device=/dev/mmcblk0p5
type=raw
parent=rootfs.0

[slot.kernel.1]
device=/dev/mmcblk0p6
type=raw
parent=rootfs.1

Mount Error:

sudo mount /dev/mmcblk0p6 /tmp/kernel/
mount: /var/volatile/tmp/kernel: wrong fs type, bad option, bad superblock on /dev/mmcblk0p6, missing codepage or helper program, or other error.

[jluebbe]

Why do you want to mount /dev/mmcblk0p6, which contains a fit image (according to your bundle recipe, and not a filesystem? That won't work.

[Rajalakshmi-Ranganathan]

Hi @jluebbe

In my project, the fitImage file name is "image.ub". My u-boot scripts and it's commands will load it only if it finds the file image.ub in the kernel vfat partition. So I am planning to use "rename" property as below to achieve it.

RAUC_SLOT_kernel[file] = "fitImage"
RAUC_SLOT_kernel[rename] = "image.ub"

So I'm trying to achieve kernel slot updates as same as rootfs.

During Rootfs slot update in Rauc:

1. Format and create ext4 partition
2. Mount the rootfs partition
3. Extract contents to the mounted folder
4. Unmount the partition

Current kernel slot update in Rauc:

1. Opening the partition slot
2. Writing the data

I think the kernel slot update actually does binary writing of fitImage contents but I wanted it to be a "cp" operation by mount and unmount a valid vfat filesystem.

Kindly help on this.

[florentsfl]

@jluebbe I understand that in this case the fitImage is written as is on the partition without a filesystem, but in this case, is the bootloader supposed to read the partition without filesystem to boot the fitImage ?

The question I have is how to boot the fitImage from the bootloader when it is written on a partition without filesystem, is it even possible ?

Because if we follow the instructions from the bundle.bbclass, it seems like to update the kernel slot we could use this

meta-rauc/classes-recipe/bundle.bbclass

Line 22 in 8992a51

# RAUC_SLOT_kernel ?= "linux-yocto"

but then that would copy a raw kernel image to a partition so I wonder if it is bootable then.

Thank you for your help