I looked at the populate-volatile.sh, and this seemed to almost do the job, if I solve the problem using symlinks. What it needs is a copy file function. As a temporary solution, I created a derivative: populate-settings.sh which will check /etc/default/settings in the same way populate-volatile.sh checks /etc/default/volatiles.
It also support copying a file, if the copy target does not exist. What I have right now is a ”writeable.bbclass” To make a file located in a read-only location, I just inherit writeable and declare it writeable in a bbappend. inherit writeable WRITEABLE = ”/etc/localtime” At build time, the ”/etc/localtime” is moved to ”/etc/update/localtime”, and ”/etc/localtime” becomes a symlink to ”/persistent/localtime” (a leading ”/etc” is shaved off) An entry to copy ”/etc/update/localtime” to “/persistent/localtime” is created in “/etc/default/settings/99_tzdata” When “/etc/init.d/populate-settings.sh” is run, “/persistent/localtime” is created. This works. Efficiency is on several levels. I am looking for a solution, where I, like above, only need to declare the name of the file. I want to avoid solutions, where I manually have to add symlinks etc. Once the symlink/bind mount is accessed, it should not eat up the CPU cycles, Kno Best Regards, Ulf Samuelsson > 14 juni 2018 kl. 01:02 skrev Andre McCurdy <armccu...@gmail.com>: > >> On Wed, Jun 13, 2018 at 9:28 AM, Ulf Samuelsson <yo...@emagii.com> wrote: >> Thanks, is it more efficient than symlinking? > > Efficient in what way? > > Have you looked at the volatile-binds recipe in oe-core? Its job is to > setup enough bind mounts to enable systemd to run from a readonly > rootfs. Although it's currently systemd specific (it only provides a > systemd service file, no init script) it might give you some clues > about how to setup bind mounts at boot time. > >> Best Regards, >> Ulf Samuelsson >> >>> 13 juni 2018 kl. 15:20 skrev Anders Darander <and...@chargestorm.se>: >>> >>> * Ulf Samuelsson <yo...@emagii.com> [180612 22:01]: >>> >>>> We want most of /etc to be read-only for security reasons, >>>> and the overlayfs will make the whole of /etc writeable. >>> >>>> I tried mount —bind /etc/timezone /persistent/etc/timezone, and it >>>> complained that they were not directories. Bind mounting /etc again >>>> will make all of /etc writeable. >>> >>> Try to use: mount —o bind /etc/timezone /persistent/etc/timezone >>> >>> I'm using that heavily, either manually or by the volatile-binds recipe. >>> It works perfectly fine with files. >>> >>>> Symlinking to /persistent is fine, so the question is what an >>>> acceptable method is to have a simple way of ensuring that a certain >>>> file is converted to that symlink. >>> >>> This is normally done by a manual inspection / addition of bbappend >>> file. >>> >>> Cheers, >>> Anders >>> -- >>> Anders Darander, Senior System Architect >>> ChargeStorm AB / eStorm AB >> >> -- >> _______________________________________________ >> yocto mailing list >> yocto@yoctoproject.org >> https://lists.yoctoproject.org/listinfo/yocto -- _______________________________________________ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto
