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Release Notes for HelenOS mainline

Note: This document is a draft describing a future HelenOS release and is subject to change. The software described here has not been released yet. To get these latest and greatest features now, check out our Git master. (But you will also get the latest bugs).

HelenOS version (codename) was released on date.

This document contains a summary of changes made to HelenOS since release previous release.

Special Notes for this Release

Features Introduced in This Release


  • HelenOS switched to the Meson build system. Among other things, this enables faster and reliable incremental builds as well as building out of the source tree.
  • The Malta machine now requires a boot command line argument to tell the userspace console layer which serial device to use as console. In the previous release this setting was baked in the kernel. Starting with this release, use the following command line to start HelenOS/mips32 Malta emulation in QEMU. Note that the console path is dependent on the PCI bus topology and might change between configurations.
    $ qemu-system-mipsel -cpu 4Kc -kernel image.boot -append "console=devices/\\hw\\pci0\\00:0a.0\\com1\\a" -nographic
  • It is now possible to boot HelenOS using U-boot on Raspberry Pi, in addition to booting it directly from the SD card.
  • Partial support for dynamic linking on ia64.


Services and Drivers

  • New window system - Display server replaces Compositor
    • New architecture, more flexible, structured, more testable
    • Mouse cursor changes over resize areas
    • Proper preview of minimum window size

File Systems


  • Added unit tests for UDP server


  • GUI applications no longer require window registration service as the first argument (it is optional)
  • Mostly fixed /app/trace (but still sometimes does not terminate correctly)
  • Bdsh alias command


  • C++ stdlib
    • <future> header
      • std::future
      • std::promise
      • std::async
      • std::packaged_task
      • std::shared_future


  • Added French keyboard layut (thx chtcheglov-ilia)

Regressions in This Release

  • For the list of regressions since the previous release, see this report.
  • Notable regressions

Fixed Logged Bugs & Enhancements

  • For the list of all logged defects fixed in this release, see this report.
  • For the list of all logged enhancements integrated in this release, see this report.

Known Bugs

  • For the list of known bugs still not fixed in this release, see this report.
  • For the list of all open tickets, see this report.
Last modified 3 months ago Last modified on 2020-07-04T22:07:46Z