Aimee OS/aimee-os/pipeline/head This commit looks goodDetails
Most of the logic in the `init-storage` script is the same as it was in
Aimee OS v1 (Gentoo). The major difference is now we are initializing
the data volume in the initramfs instead of in the real OS. This allows
us to make all of `/etc` writable via OverlayFS, instead of having only
certain sub-directories writable via bind-mounts.
Buildroot doesn't really have any tools for building an initramfs,
unfortunately. It does have a bit of infrastructure for running
`dracut`, but I'd really rather avoid having that much complexity in the
initramfs; all we need is to run the `init-storage` script and then
switch root. Instead, the `mkinitramfs.sh` script, called in the
post-build stage, creates the CPIO archive from files in the target
directory. The only particularly interesting bit is how it resolves
shared library dependencies, to make sure the appropriate resources are
available for the requisite commands.
I briefly considered building a statically-linked BusyBox just for the
initramfs. Since it doesn't provide several important tools like
`btrfs`/`mkfs.btrfs`, I had to implement the dynamic link resolution
function anyway. It made sense, then, to copy Dash and the necessary
Coreutils binaries themselves.
We set the default kernel command-line arguments to tell systemd to
spawn a debug shell on the serial console, instead of the default getty.
This will allow tests to run commands directly on the console, without
any authentication, etc.
The `AIMEEOS_DEFAULT_ROOTFLAGS` kconfig option can be used to set the
default value for the `rootflags` GRUB2 environment variable. The value
of this variable will be passed along as command-line arguments to
whatever kernel is chosen at boot.
Since post-image scripts do not have access to kconfig option values, we
need to build the GRUB2 environment file in the
`GRUB2_INSTALL_IMAGES_CMDS` script fragment instead.
If a value is provided for the `CUSTOM_TARGET` parameter, the specified
target will be built first, before building the filesystem images. This
provides a way to e.g. rebuild a specific package.
Dustin