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Release Notes for HelenOS 0.4.2

HelenOS 0.4.2 (Skewer) was released on 2010-03-10.

This document contains a summary of changes made to HelenOS since release 0.4.1.

Features Introduced in This Release


  • The project switched to Bazaar VCS.
  • The ia32 port can be run in VirtualBox again.
  • Support for building using Clang.


  • Support for the UltraSPARC T1 and T2 processors was added.

Services and Drivers

  • ATA Disk Driver
    • Now works with real disks and supports 48-bit LBA.
  • Added MBR and GUID partition table drivers.
  • On G3 Macs keyboard works again via new Apple Desktop Bus driver (and mouse is also supported).
  • Re-introduced mouse drivers, this time as separate servers.
    • PS/2 mouse
    • Apple ADB mouse
  • Clipboard service
  • Networking stack (experimental support)

File Systems

  • Block addresses and file offsets are now 64-bit on all architectures.
  • Improved I/O error handling.
  • The FAT file system is now more robust against malformed on-disk file system data.
  • The DEVFS file system now understands device namespaces and moves to hierarchical directory structure.
  • TMPFS and FAT file systems can now be unmounted.


  • New Text Editor
    • Added edit, a simple text editor.
  • Bdsh
    • Improved command input (text seek, history, copy and paste)
    • mkfile command for creating zero-filled files (e.g. disk images)
  • Tool for creating FAT file systems, mkfat


  • Build system
    • Parallel builds are now supported.
  • Spawned task now inherits the current working directory from the spawner task.
  • Stack traces
    • Upon a failed assertion the failing application will print a stack trace (all architectures except ia64 and mips32).
    • When the kernel kills a task, it will print its stack trace (all architectures except ia64, mips32, ppc32 and sparc64).
    • When the kernel panics, it will print a stack trace (all architectures except ia64, mips32, ppc32 and sparc64).
  • Core dumps (experimental support)

Regressions in This Release

  • Changes in Qemu behavior for some platforms
    • HelenOS/arm32 for Integrator/CP running in Qemu 0.11 and above will show wrong colors on the frame buffer and the keyboard presses will result in incorrect scan codes. Running in Qemu 0.10.5 does not exhibit these problems.

Known Bugs

  • For the known bugs, please see the list of defects logged for the next releases.
Last modified 4 years ago Last modified on 2012-08-08T13:15:42Z