Reproducible build

[PLangowski]

No description provided.

[m-iwanicki]

Is there no way to pass flags without patches?

[PLangowski]

I tried EXTRA_OEMAKE += "GZIP='gzip -9 -n'", but got this:

| gzip -9 -n -c pci.ids > pci.ids.gz
| gzip -9 -n -c usb.ids > usb.ids.gz
| gzip -9 -n -c oui.txt > oui.txt.gz
| gzip -9 -n -c manuf.txt > manuf.txt.gz
| gzip: gzip: gzip: abort: cannot provide files in GZIP environment variableabort: cannot provide files in GZIP environment variableabort: cannot provide files in GZIP environment variable

[m-iwanicki]

Try:

EXTRA_OEMAKE += "GZIP='-9 -n'"

[m-iwanicki]

Don't we use: usb-stick-dts.wks.in?
You can use variables directly e.g. https://github.com/Dasharo/meta-dts/blob/uki/meta-dts-distro/wic/usb-stick-dts.wks.in#L3 (setting LABEL)

[PLangowski]

The problem with this is the following:
We need to evaluate a bash command to create a uuid based on the commit SHA. I tried defining the UUIDs in this recipe and passing them to WICVARS

 ROOT_UUID="${@'$(echo ${LAYER_COMMIT_SHA} | sha256sum | cut -c1-8)-$(echo ${LAYER_COMMIT_SHA} | sha256sum | cut -c9-12)-4$(echo ${LAYER_COMMIT_SHA} | sha256sum | cut -c13-15)-$(echo ${LAYER_COMMIT_SHA} | sha256sum | cut -c16-19)-$(echo ${LAYER_COMMIT_SHA} | sha256sum | cut -c20-31)'}"
BOOT_UUID="${@'$(echo "boot-${LAYER_COMMIT_SHA}" | sha256sum | cut -c1-8)-$(echo "boot-${LAYER_COMMIT_SHA}" | sha256sum | cut -c9-12)-4$(echo "boot-${LAYER_COMMIT_SHA}" | sha256sum | cut -c13-15)-$(echo "boot-${LAYER_COMMIT_SHA}" | sha256sum | cut -c16-19)-$(echo "boot-${LAYER_COMMIT_SHA}" | sha256sum | cut -c20-31)'}"

WICVARS += "ROOT_UUID BOOT_UUID "

but the commands were not evaluated, so the variables were passed to wks in the form of commands. I'm not sure how else I could pass them aside from the original idea. Unless we want to set fixed UUIDs, then it becomes a simple matter.

[m-iwanicki]

Look at how every other recipe does this. Usually with python. I'm not sure if sh evaluation works:
https://docs.yoctoproject.org/bitbake/2.2/bitbake-user-manual/bitbake-user-manual-metadata.html#inline-python-variable-expansion

You could just define task and set value of this variable there: https://docs.yoctoproject.org/bitbake/2.2/bitbake-user-manual/bitbake-user-manual-metadata.html#exporting-variables-to-the-environment

You might write python task to begin with: https://docs.yoctoproject.org/bitbake/2.2/bitbake-user-manual/bitbake-user-manual-metadata.html#bitbake-style-python-functions
or just use this: https://docs.yoctoproject.org/bitbake/2.2/bitbake-user-manual/bitbake-user-manual-metadata.html#python-functions

BOOT_UUID="${@get_uuid('boot')}"
ROOT_UUID="${@get_uuid('root')}"

def get_uuid(string):
    import hashlib, uuid
    return str(uuid.UUID(hashlib.md5(f"{commit}{string}".encode()).hexdigest()))

you need to somehow get commit in python func. Not tested so there probably are mistakes.

[PLangowski]

I found do_rootfs_wicenv: https://git.yoctoproject.org/poky/plain/meta/classes-recipe/image_types_wic.bbclass
Maybe I can append the evaluated variables to the .env file there

[m-iwanicki]

If this doesn't work you might have to use: https://docs.yoctoproject.org/bitbake/2.2/bitbake-user-manual/bitbake-user-manual-metadata.html#immediate-variable-expansion

[m-iwanicki]

Maybe I can append the evaluated variables to the .env file there

why?

but the commands were not evaluated, so the variables were passed to wks in the form of commands

I think the problem was that you used wrong format. You can also use immediate variable expansion to make sure.
I think you tried to use bash script in python evaluation ('@'). Not only that but it's possible that it's because of ' in ${@'. It's possible that everything between '' was treated as string

[PLangowski]

Done https://github.com/Dasharo/meta-dts/compare/6615c9317c0ff58faffbc46f06dade8bc31b7f6c..81be646bee124af129961089c12c970c1e6e60e4

[m-iwanicki]

You forgot to include commit sha. I think it should be something like:

BOOT_UUID="${@get_uuid('boot' + d.getVar('LAYER_COMMIT_SHA'))}"
ROOT_UUID="${@get_uuid('root' + d.getVar('LAYER_COMMIT_SHA'))}"

Check if it works (and check if LAYER_COMMIT_SHA is evaluated correctly)

[m-iwanicki]

Working example:

• zarhus-base-image.inc#L12
• zarhus-uki.inc#L11
• zarhus-uki.wks#L3 - notice --ptable gpt in previous line, without it wic generates disk image with MBR which uses different UID format and will silently ignore --uuid, at least when it's in wrong format.

[m-iwanicki]

My previous suggestions didn't work? Because it's way more complicated and error prone

[PLangowski]

As I said, if done outside a task, they variables will not be evaluated before passed to the env

[PLangowski]

ok, I didn't see your comment above. I will try that

[m-iwanicki]

Don't use ` for shell evaluation

[m-iwanicki]

https://www.shellcheck.net/wiki/SC2006

[m-iwanicki]

You need to use bootloader --ptable gpt in wks file if you want to use long form of UUID otherwise it'd likely be ignored. MBR uses short UUID.