Generic aarch64 Linux target in reference_integration?

[fortunaLim]

Is there a way to build for aarch64 Linux with mainline glibc — that is, neither QNX nor the Elektrobit ebclfsa SDK?

Looking at .bazelrc, aarch64 appears only via qnx-aarch64 and eb-aarch64. I could not find an aarch64 counterpart to linux-x86_64.

The pieces seem to exist already, though — aarch64-linux-gcc_12.2.0-posix in bazel_platforms, and a matching entry in version_matrix.bzl — so it is quite possible I am just missing how this is meant to be used.

If there is no such config today, is that a deliberate scope decision, or simply something nobody has needed yet?

[opajonk]

I guess the problem is not so much to build for aarch64; that is "easily done", as you say. S-CORE has a few dependencies on the OS, but that can be quite easily covered functionally. Looking e.g. at the few ".deb" files that are pulled in here in baselibs can be instructive.

The more interesting part is: what do you do with it? "Just running it"? Then why not use x86_64, which I assume still has the biggest share of development CPU architectures, and it all just works.

Running it on an embedded device with aarch64 architecture? Well, you have the eb-aarch64 tool-chain for cross-building, as you say. To be quite honest, that tool-chain at the moment is nothing but a GCC which cross-builds statically linked binaries for something which at a functional level is a Debian Trixie. For Rust, we at this moment even employ the already existing Ferrocene toolchain, configured for static linking. So... I think you should be able to put the binaries it creates onto many aarch64 devices and they will "just work" like that (Disclaimer: I did not check that now, of course). I would not see big blockers.. just giving it a try would be worth it. In other words, there is no need to use the EB corbos Linux for Safety Applications image here, if you don't want to.

An entirely different story all of this will be when you ultimately want to build a dependable system of any kind based on S-CORE. However, I assume that is not your current goal.

[opajonk]

Now I was curious ;-)

As development host I am using an Ubuntu 24.04 LTS system with all tools installed to run a DevContainer and VSCode. I have a Raspberry Pi 5 with a recent stock Raspbian on it, denoted as host raspi5 below. Raspbian is Debian Trixie based, which I admit is "rather close" to EB corbos Linux for Safety Application's default user-space, so YMMV with other distros.

Then:

1. Git clone reference_integration, latest main branch.
2. Using VSCode, open the repository, in the DevContainer that it comes with (takes a minute or two).
3. In VSCode, open a Terminal and then build the showcases package:

$ bazel build --lockfile_mode=error --config=eb-aarch64 //showcases:showcases_pkg_tar
[...this will take some time and output lots of logs]
INFO: Found 1 target...
Target //showcases:showcases_pkg_tar up-to-date:
  bazel-bin/showcases/showcases_pkg_tar.tar
INFO: Elapsed time: 275.816s, Critical Path: 132.45s
INFO: 1992 processes: 309 action cache hit, 90 disk cache hit, 340 internal, 1562 processwrapper-sandbox.
INFO: Build completed successfully, 1992 total actions
$ scp bazel-bin/showcases/showcases_pkg_tar.tar user@raspi5:
showcases_pkg_tar.tar                                                                                                      100%  115MB  87.4MB/s   00:01
$ ssh user@raspi5
Linux raspi5 6.18.33+rpt-rpi-2712 #1 SMP PREEMPT Debian 1:6.18.33-1+rpt1 (2026-06-01) aarch64

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Thu Sep  3 22:13:08 2026 from X.X.X.X
$ uname -a
Linux raspi5 6.18.33+rpt-rpi-2712 #1 SMP PREEMPT Debian 1:6.18.33-1+rpt1 (2026-06-01) aarch64 GNU/Linux
$ mkdir foo
$ cd foo/
$ tar xvf ../showcases_pkg_tar.tar 
showcases/
showcases/bin/
showcases/bin/cli
showcases/bin/com-api-example
showcases/bin/config_daemon
showcases/bin/control_daemon
showcases/bin/cpp_supervised_app
showcases/bin/dlt_generator
showcases/bin/high_res_steady_time
showcases/bin/launch_manager
showcases/bin/lifecycle_signal.sh
showcases/bin/logging_app
showcases/bin/main_macro
showcases/bin/rust_supervised_app
showcases/bin/safety_task
showcases/bin/select
showcases/bin/steady_time
showcases/bin/system_time
showcases/bin/vehicle_time
showcases/configs/
showcases/configs/com.score.json
showcases/configs/config_management.score.json
showcases/configs/kyron.score.json
showcases/configs/logging.score.json
showcases/configs/simple_lifecycle.score.json
showcases/configs/time.score.json
showcases/data/
showcases/data/comm/
showcases/data/comm/etc/
showcases/data/comm/etc/mw_com_config.json
showcases/data/config_management/
showcases/data/config_management/etc/
showcases/data/config_management/etc/demo_parameters.json
showcases/data/config_management/etc/mw_com_config.json
showcases/data/logging/
showcases/data/logging/dlt_generator/
showcases/data/logging/dlt_generator/etc/
showcases/data/logging/dlt_generator/etc/logging.json
showcases/data/logging/logging_app/
showcases/data/logging/logging_app/etc/
showcases/data/logging/logging_app/etc/logging.json
showcases/data/simple_lifecycle/
showcases/data/simple_lifecycle/etc/
showcases/data/simple_lifecycle/etc/hm_demo.bin
showcases/data/simple_lifecycle/etc/hmcore.bin
showcases/data/simple_lifecycle/etc/lm_demo.bin
showcases/data/simple_lifecycle/etc/logging.json
$ cd bin
$ ./safety_task 
2026-09-03T20:06:57.114875Z DEBUG main ThreadId(01) Registered worker UniqueWorkerId(193489873)
2026-09-03T20:06:57.120234Z DEBUG ThreadId(02) Safety worker UniqueWorkerId(14144299263607051467) started
2026-09-03T20:06:57.120300Z DEBUG ThreadId(03) Parking on IO Driver with timeout: None
2026-09-03T20:06:57.120341Z DEBUG main ThreadId(01) Engine starts waiting for workers to be ready
2026-09-03T20:06:57.120363Z DEBUG ThreadId(04) Parking on CV without timeout
2026-09-03T20:06:57.120471Z DEBUG main ThreadId(01) Workers ready, continue...
2026-09-03T20:06:57.120541Z DEBUG ThreadId(03) Unparked on IO Driver with result: Ok(())
2026-09-03T20:06:57.120540Z DEBUG ThreadId(05) Dedicated worker UniqueWorkerId(193489873) started
2026-09-03T20:06:57.120578Z DEBUG ThreadId(04) Unparked from CV(from park_on_cv) by notification
2026-09-03T20:06:57.120586Z  INFO ThreadId(03) Parent task. Worker ID: WorkerId { unique_id: UniqueWorkerId(7572170704431216), engine_id: 0, worker_id: 0, typ: Async }, Task Id: TaskId(65535)
2026-09-03T20:06:57.120604Z DEBUG ThreadId(04) Parking on IO Driver with timeout: None
2026-09-03T20:06:57.120634Z DEBUG ThreadId(04) Unparked on IO Driver with result: Ok(())
2026-09-03T20:06:57.120637Z  INFO ThreadId(03) =============================== Spawned all tasks ===============================
2026-09-03T20:06:57.120654Z  INFO ThreadId(05) Dedicated worker (dw1): passing_non_safety_task. Worker ID: WorkerId { unique_id: UniqueWorkerId(193489873), engine_id: 0, worker_id: 2, typ: Dedicated }, Task ID: TaskId(196608)
2026-09-03T20:06:57.120662Z  INFO ThreadId(03) Worker-N: passing_safety_task. Worker ID: WorkerId { unique_id: UniqueWorkerId(7572170704431216), engine_id: 0, worker_id: 0, typ: Async }, Task ID: TaskId(131072)
2026-09-03T20:06:57.120661Z  INFO ThreadId(04) Worker-N: failing_safety_task. Worker ID: WorkerId { unique_id: UniqueWorkerId(7572170704431217), engine_id: 0, worker_id: 1, typ: Async }, Task ID: TaskId(65536)
2026-09-03T20:06:57.120712Z DEBUG ThreadId(03) Notified while try to sleep, searching again
2026-09-03T20:06:57.120726Z DEBUG ThreadId(04) Notified while try to sleep, searching again
2026-09-03T20:06:57.120735Z DEBUG ThreadId(03) Parking on IO Driver with timeout: None
2026-09-03T20:06:57.120730Z  INFO ThreadId(02) Since safety task fails, safety worker may execute parent task from this statement onwards.
2026-09-03T20:06:57.120746Z DEBUG ThreadId(04) Parking on CV without timeout
2026-09-03T20:06:57.120754Z  INFO ThreadId(02) Parent task. Worker ID: WorkerId { unique_id: UniqueWorkerId(14144299263607051467), engine_id: 0, worker_id: 3, typ: Dedicated }, Task Id: TaskId(65535)
2026-09-03T20:06:57.120795Z  INFO ThreadId(02) Program finished running.
2026-09-03T20:06:57.120819Z  INFO main ThreadId(01) Exit.
2026-09-03T20:06:57.120848Z DEBUG ThreadId(03) Unparked on IO Driver with result: Ok(())
2026-09-03T20:06:57.120851Z DEBUG ThreadId(04) Worker1 received stop request, shutting down
2026-09-03T20:06:57.120867Z DEBUG ThreadId(03) Worker0 received stop request, shutting down
2026-09-03T20:06:57.220756Z DEBUG ThreadId(05) Dedicated worker UniqueWorkerId(193489873) stopping
$ ./system_time 
SystemTime printer started. Press Ctrl+C to stop.
[0]  unix=1788466090.406404029 s
[1]  unix=1788466091.406482626 s
[2]  unix=1788466092.406559599 s
[3]  unix=1788466093.406637075 s
[4]  unix=1788466094.406716166 s
[5]  unix=1788466095.406796798 s
^CShutdown requested. Exiting.
$

I started a few other executables, which were unhappy about their configuration situation - but they all started fine. So, as I expected - that "just works".

[fortunaLim]

Thank you, and especially for actually running it. That answers it completely.

I had read eb-aarch64 as being specific to the EB corbos Linux image, so it did not occur to me that it is effectively a general purpose statically-linked aarch64 Linux cross-build. That is a very useful thing to know.

That also makes sense of your pointer to baselibs: the OS-facing surface being small is what makes it hold up.

[opajonk]

At least at this moment it is not really very specific, so feel free to use it. This will likely change in later versions, where we will have to change libc and compiler, but this is not the case right now.