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                      Bedrock Linux

Introductory Material

Limitations

Reference Material

Extending Bedrock

Miscellaneous


© Bedrock Linux 2012-2020
Linux® is a registered
trademark of Linus Torvalds

Bedrock Linux 0.7 Poki Feature Compatibility

Feature How well it works Notes
cross-stratum bash completion Mostly Works Install bash-completion in all strata; some completions fail
cross-stratum fish completion Just Works
cross-stratum zsh completion Mostly Works Install zsh in all strata; some completions fail
cross-stratum applications Minor Work-around Clear cache to update application menu
cross-stratum dbus Just Works
cross-stratum desktop environments Major Issues Requires hand-crafted, Bedrock-aware configuation.
cross-stratum dkms Mostly Works Sometimes must pair dkms and kernel
cross-stratum executables Just Works
cross-stratum firmware Mostly Works Kernel will detect firmware across strata, initrd-building software needs investigation
cross-stratum info pages Just Works
cross-stratum init configuration Major issues Requires hand-crafted, Bedrock-aware configuration.
cross-stratum libraries Does Not Work Theoretically possible but unsupported due to complexity/messiness concerns
cross-stratum login shells Just Works Specifying stratum requires special configuration
cross-stratum man pages Just Works
cross-stratum themes Mostly Works Works work themes that support $XDG_DATA_DIRS
cross-stratum vt fonts Does Not Work Needs research
cross-stratum Wayland Fonts Needs Testing Needs research
cross-stratum Xorg fonts Reports of inconsistency Deeper investigation needed
ACLs Mostly Works Does not work in /etc
Any stratum's init Mostly Works Select init at init-selection menu during boot; see BSD style SysV notes
Any stratum's kernel Mostly Works Install kernel from stratum then update bootloader
AppArmor, TOMOYO, SMACK Needs Testing Default profiles unlikely to work
BSD-style SysV init Major Issue Freezes on shutdown
build tools (e.g. make, configure scripts, etc) Minor Work-around Often confused without strat -r
grubs+btrfs/zfs Major Issue GRUB miss-updates grub.cfg on btrfs/zfs in Bedrock
nVidia proprietary drivers Manual Work-around Manually install drivers in relevant strata
pamac/octpoi Inconsistent Reports Inconsistent reports
ptrace (e.g. gdb, strace) Minor Work-around Install in same stratum as traced program, strat -r
SELinux Does Not Work Bedrock disabled on hijack
systemd-shim Major Issue logind access denied
timeshift Major Issue Confused by filesystem layout; do not use with Bedrock

Application Launchers

Many application launchers cache known applications and/or their icons. Some may fail to recognize new applications in /bedrock/cross/applications or icons in /bedrock/cross/icons.

Some such applications can be prompted to build the cache by removing ~/.cache and restarting the application menu provider (e.g. logging out and back in).

Application Launcher specific cache updating techniques:

Login shells

Linux systems typically store the full path to a login shell in /etc/passwd. Default login shell paths are local and will not be visible to another stratum's init system. Bedrock automatically changes any local login shell to a cross path in /bedrock/cross/bin/ to work around this concern.

If you would like to use a specific stratum's shell rather than the highest priority one, create a pin entry in cross-bin with the desired shell. After brl applying the new configuration, add the new pin path to /etc/shells and chsh to it.

Init configuration

Every stratum sees its own init configuration and only its own init configuration. By default, an init from one stratum will not know how to manage a service from another stratum's init.

It is possible to work around this by hand crafting init configuration. For example, one may make a runit run directory whose run file calls strat. For another example, one may make a systemd unit file whose Exec= line calls strat.

If you find hand creating init configuration is intimidating or bothersome, consider simply picking one stratum to provide your init and get all init-related services from that stratum.

Desktop Environments

Generally, getting:

all from the same stratum works as expected, and is the recommended workflow for most users.

The wiring between these components does not work automatically register across stratum boundaries. There are two components to this issue:

It is possible to make cross-stratum desktop environments work if the relevant init configuration is made by hand to launch all of the DE's dependencies. Whether /usr/share/xsessions changes are also needed depends on the specific init configuration strategy utilized. This may be difficult for some users and is not broadly recommended.

dkms

Cross-stratum dkms usage on Bedrock almost always works, with one exception.

dkms needs to see two code bases to work:

Bedrock can make the former work across stratum boundaries. A dkms from any stratum will automatically be able to pick up and use things like nVidia or Virtualbox module code from other strata.

Bedrock's ability to make the latter work across strata depends on how the kernel-providing distro sets up its kernel headers. Some distros place the header source directly at

/usr/lib/modules/version/build/

For example, Arch Linux does this. If such a distro provides your kernel, dkms from non-kernel strata can detect the kernel's headers.

Other distros make the kernel header source directory a symlink to a local location. For example, Debian symlinks them into /usr/src/. dkms from other non-kernel strata will be unable to follow such symlinks.

In practice, this means:

In the scenario where dkms does not detect headers cross-stratum, one may manually run the kernel stratum's dkms with strat to build and install the module:

strat -r target-kernel-stratum dkms install module/module-version -k target-kernel-version

Table

dkms binary is from kernel stratum dkms module is from kernel stratum kernel headers are local symlink Just Works
Yes Yes Yes Yes
Yes Yes No Yes
Yes No Yes Yes
Yes No No Yes
No Yes Yes No
No Yes No Yes
No No No Yes
No No Yes No

BSD Style SysV

BSD-style SysV init systems, such as used by Slackware and CRUX, freeze on shutdown when run on Bedrock.

The leading theory is:

Quick and dirty tests show etcfs normally umounts on SIGTERM from root. It is not clear why this might not be happening during SysV shutdown. Bedrock's etcfs code does not do any direct signal handling. Debugging this may require digging into libfuse's code to see how it handles signals.

systemd-shim

On MX Linux, the logged in user is expected to get certain permissions granted from systemd-logind, such as the ability to use the desktop environment's menu to reboot the system.

When running in Bedrock, this does not appear to work. This is likely due to MX Linux's use of SysV and systemd-logind via systemd-shim. The issue does not occur either on pure systemd systems nor on pure SysV systems.

Investigation found some process was reading local copies of what should have been global /etc files. This process was somehow reading /etc content under the etcfs mount. It is not clear what process was doing this, nor how it was doing so.

Manually writing through global /etc files to the init stratum (and consequently, systemd-logind's and systemd-shim's stratum) resolved the issue. However, automating this is not suitable as a general solution due to both performance and implementation complexity concerns.

Grub with BTRFS or ZFS

When GRUB updates grub.cfg on BTRFS it adds a subvol= field. Similarly, on ZFS it adds a ZFS= field.

GRUB's logic to populate these fields via grub-mkrelatph/grub2-mkrelpath appears to be confused under Bedrock and mis-populate the BTRFS and ZFS fields. This will cause boot failures.

Until this is resolved, it is strongly recommended not to use Bedrock, GRUB, and BTRFS/ZFS. Any two of the three is fine; consider another bootloader or filesystem.

Some quick digging into grub-mkrelpath's source found:

This is fine on most distros which only mount the root partition once. However, Bedrock's use of bind-mounts results in multiple /proc/self/mountinfo entries with the same major:minor number, which in turn means grub-mkrelpath may grab the wrong one.

Pamac and Octopi

Inconsistent reports have been provided for how well pamac and octopi work on Bedrock, both on Manjaro and Arch via AUR. Investigation may be needed.

Nvidia proprietary drivers

Most Linux graphics drivers have two components:

Most F/OSS Linux graphics drivers strive to make the two components forward and backward compatible such that their versions do not have to sync up perfectly. This allows a kernel from one stratum to work with an Xorg server from another stratum. However, the proprietary Nvidia drivers require these two components be in sync. Since the kernel module is shared across strata, this means every stratum that does anything with the graphics card requires the exact same version. Bedrock does not know how to enforce this itself. To work around this, one must manually install distro-agnostic portable proprietary Nvidia in all strata.

Download the proprietary Nvidia driver. Then run

where kernel-stratum is the stratum providing your kernel. This may require a linux-headers package be installed in the kernel-stratum. Note the -r: this is important to keep the Nvidia driver installer from "cleaning" graphics related files in other strata.

Next, run

for all remaining strata that require graphics drivers.

The bedrock stratum and other strata that do not utilize the graphics acceleration do not require the Nvidia drivers.