fs/custom: generate complete, partition-based device images

Hi,

I was looking for a way to customize the root file system in the way, that all except /var is read only. And /var is at a separate partition which will be enlarged at the first start to the maximum size of the storage media. (I'm using RPi 3)

I'm using BR 2017.02.1. The above patch seems not to be included yet. And I didn't fount any discussion about accepting the patch. Is there a other way to solve my issue?

Thanks and regards,
Jan Schmidt

Jan, All,

On 2017-08-29 13:27 +0200, Jan Schmidt spake thusly:

At first, I was very puzzled about what patch this was refering to. ANd it truns out it was something I wrote almost 4 years ago... Damn, time flies...

Anyway, back on topic: no, that was not accepted at all, see the discussion in the thread:

    https://patchwork.ozlabs.org/patch/306631/

So, the best option for you is that you do something like:

- only generate a tarball out of Buildroot,
- provide a post-image script that:
- extract the tarball into ${TMP_ROOT_DIR}
- generate an ext2 (or other writable FS) out of ${TMP_ROOT_DIR}/var
- remove ${TMP_ROOT_DIR}/var/*
- tweak ${TMP_ROOT_DIR}/etc/fstab to add the mountpoint for /var
- create the readonly root fs with out of ${TMP_ROOT_DIR}/

Note that the post-image script should run under fakeroot, and Buildroot does not guarantee that, so your script would probalby need to start with something like:

    if [ $(id -u) -ne 0 ]; then
        fakeroot "${0}" "${@}"
        exit ${?}
    fi

which would ensure that the script runs under fakeroot.

Regards,
Yann E. MORIN.

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