Resize rootfs partition in a Ubuntu OS Image (Fenix) for VIM3

Technical Support
1

In order to use a read-only partition for the filesystem, i want to implement an overlay feature. To do so, the system has to be already partitioned with a working boot-loader and two partitions, the first one bootable. see the following link: Read-only root with overlayfs

However, our Image isn’t partitioned and only have a rootfs partition, that we couldn’t split and resize, without compromising the whole disk.

The idea was to apply the modifications before building the OS Image thanks to Fenix.

In the build-rootfs file, we modified part of the code related to disk partitioning to limit the size of the rootfs and to create another partition with the same size that we need for implementing the overlay:

		if [ "$GENERIC_IMAGE_PARTITION_TABLE" != "gpt" ]; then

			fdisk "${BUILD_IMAGES}/${IMAGE_FILE_NAME}" <<-EOF
			o
			n
			p
			1
			32768
			524287
			a
			t
			b
			n
			p
			2
			524288
			33540096
			n
			p
			3
			33540097
            67106815
			p
			w
			EOF
		else
			parted -s ${BUILD_IMAGES}/${IMAGE_FILE_NAME} mklabel gpt
			parted -s ${BUILD_IMAGES}/${IMAGE_FILE_NAME} unit s mkpart boot 32768 524287
			parted -s ${BUILD_IMAGES}/${IMAGE_FILE_NAME} unit s mkpart rootfs 524288 33540096
			#parted -s ${BUILD_IMAGES}/${IMAGE_FILE_NAME} unit s mkpart data 33540097 67106815
			#parted -s ${BUILD_IMAGES}/${IMAGE_FILE_NAME} set 1 boot on
		fi

You’ll find below the fdisk command that are used. The numbers are the values of the sector where the partition start and where it ends.

Screenshot from 2024-02-02 17-38-46
Screenshot from 2024-02-02 17-38-46478×674 38.6 KB

I also added this line in the config/config file:

#IMAGE PARTITION TABLE TYPE
GENERIC_IMAGE_PARTITION_TABLE="gpt"

Here is the result:

Screenshot from 2024-02-02 17-32-34
Screenshot from 2024-02-02 17-32-34561×604 42 KB

Our disk is still not splited even after modifing the files before building the image.
Do you have any tips to go further ? thank you so much for your help

1 Like
2

Dear Khadas team @numbqq, do you have some information about this ? to split partitions on Ubuntu image (fenix). Thanks a lot for your help.

3

Hello @Rayane_Mechik @JJ1997

You also need to change the dts to modify the partitions.