Version 10 (modified by Jiri Svoboda, 14 years ago) ( diff )

Add deadlock detection

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 Bazaar mainline. (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 0.4.2.

Special Notes for this Release


Features Introduced in This Release


  • New boot infrastructure
    • The new boot infrastructure is more unified and offers similar boot behavior on all supported platforms.
  • PearPC support discontinued
    • PearPC was the original PowerPC simulator used for the development of HelenOS ppc32 port. However, since this simulator is no longer in active development and even severe flaws have not been fixed for more that 4 years (OFW memory management calls, etc.), we have decided to drop support for this simulator completely instead of adding more quirks to our bootloader and kernel code. Qemu/PPC is currently our PowerPC simulator of choice.
  • Added support for the Neo FreeRunner smartphone (based on the ARMv4 architecture).
  • Deadlock detection for fibril mutexes.


  • Observability
    • Kernel panics now have a more unified look and print more informative, meaningful and compact messages.
    • Experimental support for kernel stack traces on mips32, ppc32 and sparc64.

Services and Drivers

  • Item

File Systems

  • FAT file system server
    • Sequential file I/O has linear time complexity in number of blocks for most use patterns. Previously, time complexity of sequential I/O was always quadratic in number of blocks.


  • Statistics
    • Added top utility which can print nearly real-time statistics for various system entities.
    • Added stats utility which prints load-related system statistics.
    • Added tasks utility to list tasks, threads and CPUs.
  • Languages
    • Added sbi interpreter of the Sysel experimental programming language.


  • Item

Regressions in This Release

  • Item
    • Description

Known Bugs

  • For the known bugs, please see the list of defects logged for the next releases.
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