How to execute a script in swupdate image recipe in Yocto?

Question

I am unable to execute a shell script(create_signed_swu.sh) in my recipe(panther2-swu.bb) which inherit swupdate and if I remove inherit swupdate, I see do_compile gets compiled and script executes successfully. Here is panther2-swu.bb recipe:

DESCRIPTION = "Building swupdate image (.swu ) for panther2  board"

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

inherit swupdate
FILESEXTRAPATHS_append := "${THISDIR}/../../../../build/tmp/deploy/images/panther2/"

SRC_URI = "file://sw-description \
          file://postinstall_swu.sh \
          file://bzImage \
          file://create_signed_swu.sh \
          file://priv.pem \
          file://passphrase \
        "
do_compile() {
        ${WORKDIR}/create_signed_swu.sh
}
DEPENDS = "openssl-native"

Here is the create_signed_swu.sh:

#!/bin/bash

IMAGES="bzImage panther2-usb-panther2.ext4"
FILES="sw-description sw-description.sig postinstall_swu.sh $IMAGES"
echo "Executing swu signing script..."

cp ../sw-description .
cp ../postinstall_swu.sh .
cp ../../../../../deploy/images/panther2/bzImage .
cp ../../../../../deploy/images/panther2/panther2-usb-panther2.ext4 .

read -d ' ' SHA_ROOTFS < <(sha256sum panther2-usb-panther2.ext4)
read -d ' ' SHA_BZIMAGE < <(sha256sum bzImage)
read -d ' ' SHA_POSTINSTALL < <(sha256sum postinstall_swu.sh)

sed -i ':a;N;$!ba; s/sha256 = "[0-9A-Za-z]*"/sha256 = '"\"${SHA_ROOTFS}"\"'/1' sw-description
sed -i ':a;N;$!ba; s/sha256 = "[0-9A-Za-z]*"/sha256 = '"\"${SHA_BZIMAGE}"\"'/2' sw-description
sed -i ':a;N;$!ba; s/sha256 = "[0-9A-Za-z]*"/sha256 = '"\"${SHA_POSTINSTALL}"\"'/3' sw-description

openssl dgst -sha256 -sign ../priv.pem -passin file:../passphrase sw-description > sw-description.sig

for i in $FILES;do
        echo $i;done | cpio -ov -H crc >  panther2-swu-$USER-devbuild.swu

cp panther2-swu-$USER-devbuild.swu ../../../../../deploy/images/panther2

rm -f sw-description
rm -f postinstall_swu.sh
rm -f sw-description.sig
rm -f bzImage
rm -f panther2-usb-panther2.ext4
rm -f panther2-swu-$USER-devbuild.swu

I have tried ROOTFS_POSTPROCESS_COMMAND as well but it doen't execute my srcipt either.

Any help would really be appreciated, Thanks in advance...!!!

you should look at [examples](https://github.com/sbabic/meta-swupdate-boards) to integrate swupdate in Yocto. meta-swupdate will compute signed images automatically, [this file](https://github.com/sbabic/meta-swupdate/blob/master/README) explains it pretty well. — Nayfe, Apr 29 '19 at 06:42

score 1 · Answer 1 · answered Jul 28 '19 at 15:58

Generating a SWU does not compile anything and not only do_compile, but even do_configure is turned off. The class "swupdate" has an own task : do_swuimage. Changes to default behaviour can be done with a do_swuimage_append(). Anyway, the script above makes no sense: the class does exactly what the script is trying to do, and provide variable substitutions to automatically set sha256 and other values. The "sed" entries make no sense, as well as signing in this script. Instead of that, the class should be inherited and variables must be (all of them starting with SWUPDATE_, please check in documentation) to let the class to do its job. The script is a variant of the script inserted in the documentation to build outside Yocto - instead of following this approach, the functionalities in meta-swupdate should be used.

score 0 · Answer 2 · answered Apr 29 '19 at 15:43

If removing the inherit swupdate makes your do_compile execute and launch your script it means that the class swupdate.bbclass do not execute the do_compile task. The class surely has this line :

do_compile[noexec] = "1"

Which means that the do_compile is not excuted at all.

You could choose between two solutions:

Using prepend/append of some task:

Prepend/append your recipe's task that is meant to launch the script to an existing task like following :

Assuming the do_configure is launched :

do_configure_append() 
{
 ${WORKDIR}/create_signed_swu.sh
}

This will launch your script at the end of do_configure.

Creating your own task:

Assuming you want to launch your script before do_build task

do_launch_script () {
     ${WORKDIR}/create_signed_swu.sh
}
addtask launch_script after do_configure before do_build

How to execute a script in swupdate image recipe in Yocto?

2 Answers2