The L4Ka team is happy to announce the release of L4Ka::Pistachio version 0.4. With L4Ka::Pistachio the L4Ka team aims at providing a robust, portable, high performance implementation of the L4 Version 4 API.
It has been a long time since our last release, but we hope that all the new functionality and bug fixes were worth the wait. Among other things, the version 0.4 release adds support for 3 new hardware architectures. All in all the L4Ka::Pistachio kernel now runs on the following architectures:
o Intel IA32 (Pentium and higher) o Intel IA64 (Itanium1, Itanium2, Ski) o AMD64 [NEW] o PowerPC 32bit (IBM 750) o PowerPC 64bit (Power3, Power4) [NEW] o Alpha (21164) o MIPS 64bit (R4000, VR41xx, R5000) o ARM (SA1100, XScale, ARM925T) [NEW]
L4Ka::Pistachio version 0.4 incorporates a number of enhancements, modifications, and bug fixes. The following is a list of the major architecture independent changes since the last release:
o Most system calls have been extended to report error codes upon failure. This substantially improves the ease of application development.
o The kernel now implements "over-mapping" of flexpages correctly. Over-mapping occurs when a new page frame is mapped into the location of an already existing page frame in the destination address space.
o Better support for reporting and resetting reference bits.
o The ExchangeRegisters system call has been modified so that it can no longer activate inactive threads.
o The L4 Version 4 API now specifies an architecture independent protocol for communicating boot loader specific data to the application programs. This protocol is supported by several L4 bootloaders (including kickstart).
o Sigma0 now implements setting of memory attributes.
o A bug (actually several bugs) in sigma0 would in some cases cause sigma0 to refuse to hand out certain memory regions, or cause incorrect memory to be handed out.
o A new 'grabmem' example application has been added to the distribution.
The following is a list of architecture specific changes and additions:
Alpha: o Added FPU support. o Implemented SystemClock system call.
AMD64: o This release adds support for the AMD64 architecture to L4Ka::Pistachio. o The AMD64 kernel is almost feature complete. It only lacks support for I/O flexpages and implementations of the Lipc, ProcessorControl and MemoryControl system calls. It also does not support SMP yet. o The kernel also features a hand-optimized fast IPC path.
ARM: o This release adds support for the ARM architecture to L4Ka::Pistachio. o PLEB (Intel StrongARM SA-1100), Intel XScale IXP425 and TI OMAP1510 (ARM925T) platform support is included. o The kernel features fast address-space switching (FASS) [1] as a compile option. o The kernel is currently missing a fast-IPC path. Even without this optimization, context-switching and IPC performance across address spaces, when FASS is used appropriately, improves on any existing ARM implementation of L4 by approximately two orders-of-magnitude. o As with other architectures in L4Ka::Pistachio, currently no LIPC optimization is implemented - the LIPC path is identical to the IPC path.
IA32: o Added a proper implementation of the SystemClock system call. o The support for small address spaces has been greatly improved. o Fixed a bug in the interrupt handing code that caused edge triggered interrupts to be handled incorrectly. o The kickstart utility now handles a number of command line options (see http://l4ka.org/projects/pistachio/kickstart.php for details).
IA64: o The kernel now supports lazy handling of the upper 96 floating-point registers. o Preliminary support for performance profiling has been added. o Fixed a bug in the fast-IPC path that could cause interrupt handling to crash the kernel. o Low-level performance optimizations. o Fixed SystemClock system call to always report correct times.
MIPS 64bit: o The kernel has been fixed to compile without debugging. o Added support for NEC VR41XX processors. o Changed the system call encoding. o The fast-IPC path has been fixed. o Reworked the exception handling code. o More accurate timer implementation. o Floating point support. o SMP support.
PowerPC 32bit: o The kernel can run without debugging and without the debugger. o Proper exception message dispatching, including support for the system call exception. o Added correct implementation of the SystemClock system call. o Can prevent verbose kernel initialization. o Added a user-level I/O driver for the psim COM port, which can be used when the kernel is compiled without debug support. o Code restructuring to (1) minimize code, (2) improve readability, and (3) parameterize more kernel features.
PowerPC 64bit: o This release adds support for the 64 bit PowerPC architecture to L4Ka::Pistachio. o The kernel supports Power3 and Power4 architectures (no SMP). o Optimized selective SLB replacement context switching on Power4.
For more information on L4Ka::Pistachio and the L4 Version 4 API in general, refer to the L4Ka::Pistachio whitepaper:
http://l4ka.org/projects/pistachio/pistachio-whitepaper.pdf
L4Ka::Pistachio is available under the two-clause BSD license. Source and binary distributions, documentation, and other online resources can be found on the L4Ka website:
The latest version of L4Ka::Pistachio, including any changes since the latest release, is also available through a public read-only CVS repository. See our website for instructions on how to access the public CVS.
Happy hacking,
The L4Ka Development Team
[1] A. Wiggins, H. Tuch, V. Uhlig, and G. Heiser. Implementation of Fast Address-Space Switching and TLB Sharing on the StrongARM Processor. In Eighth Asia-Pacific Computer Systems Architecture Conference (ACSAC'03), Aizu-Wakamatsu City, Japan, September 23-26, 2003.