The minimal memory reserved parameter vm.min_free_kbytes should be
between 1-3% according to RedHat.
However, the kernel by default reserves around 3MB (e.g. only 3285 on a
32-bit Raspberry Pi 4 2GB installation). This seems to be too low for
network intensive applications such as ours: Under memory pressure
"page allocation failure" on various orders have been observed.
Raspberry Pi OS uses a fixed value of 16MB. Follow this setting for now.
Note: We cannot set this globally for Home Assistant: x86-64 machines
can have quite a bit more memory, which also requires increased
min_free_kbytes parameter. ODROID-N2 on the other hand uses transparent
huge pages: If enabled, the kernel requires higher min_free_kbytes
values, and sets those also by default (e.g. on ODROID-N2+ with 4GB
memory its set to 22528 by default).
Don't fail adding reserved memory when a memory region already has been
reserved (e.g. via memreserve). This avoids conflicting no-map setting
and makes sure memory is properly reserved.
* Enable some useful kernel configurations
* Add xe-guest-utilities for better Xen support
Add guest utilities and make sure the Xen guest daemon gets started
when running under Xen virtualization.
* Avoid using tar when uploading dev builds
The GitHub action to upload the images to the os-builds server uses
tar before uploading. This creates unnecessary copies and takes a while.
Switch to a GitHub action which uploads the images using rsync instead.
Other compression methods remove the original image file at compression.
Add the -m (move) command to zip to do the same when compressing with
zip. This saves some space in the builds image/release directory.
The CRDA (Central Regulatory Domain Agent) utility has been used as a
user space helper to load regulatory information for WiFi drivers.
However, since Linux 4.15 the kernel can load the regulatory information
directly from a signed firmware file "regulatory.db".
The regulatory.db file is provided by the WIRELESS_REGDB package, which
has been already installed since its a dependency of CRDA.
Drop CRDA and select WIRELESS_REGDB package explicitly to make sure the
regulatory.db file is present.
LVM2 is not really required in the embedded use case. Opt out of
installing the standard installation which will install only dmsetup.
This requires a backported fix for the lvm2 package to not install
unnecessary systemd services.
Fixes: #1448
* Drop buildroot from git repository
Manage buildroot in a separate git repository and use a git submodule
to include it into the HAOS source tree.
This makes it easier to manage changes to buildroot since it can be
managed by git. A buildroot fork repository is being maintained with
the changes we currently have. It makes the buildroot-patches unnecessary
and should make it easier to rebase and upstream changes to buildroot.
* Remove buildroot-patches
Now that buildroot changes are managed in the buildroot fork repository
there is no need to manage patches in a separate directory.
* Initialize git submodule if necessary
* Move build directory to root
This avoids conflict/local modification issues with the buildroot
git submodule.
* Improve kernel update scripts
Use separate script for ODROID-N2 for now. Also warn if there are kernel
patches with a specific kernel version number in the source tree: They
typically can be just moved to the new kernel version, but one should
compile check them before committing.
* Add squashfs with LZ4 and LZO compression to Barebox
* Add squashfs with LZO compression to U-Boot
* Use squashfs for Linux kernel partition
Generate a squashfs image with LZO compression for the Linux kernel
partition. Adjust the boot scripts to be file system independent commands
to boot from squashfs.
The patches for ODROID-C2/C4 don't apply to Linux 5.12 used in
ODROID-N2. Move ODROID-C2/C4 patches to kernel version specific
directory so they don't get applied for ODROID-N2.
Use the latest Linux stable release 5.12 for ODROID-N2. This allows to
test if we see the random kernel crashes observed with 5.10 in latest
stable 5.12 as well.
The rauc hook for the spl slotclass writes to the disk directly. Make
sure the changes do not end up in cache in case the device looses power
or is otherwise not properly rebooted.
Also use the same partition label detection we are using in
hassos-expand.
In the past file system extents have been deactivated to get better
performance in U-Boot. However, the performance issue has been addressed
with commit d5aee659f217 ("fs: ext4: cache extent data") in U-Boot. The
performance should be equal to regular files using no extents.
Enabling extents has an advantage however: Files are stored more
efficently, especially relatively large files like a kernel image. The
impact is not all that big (~100KiB), but worthwhile nonetheless.
The Wireless Extension framework is deprecated, but it seems that the
Wireless Extensions proc API is still popular (/proc/net/wireless).
Enable the minimal set of Wireless Extension to get the proc API.
