Quark (kernel)

In computing, Quark is an operating system kernel used in MorphOS. It is a microkernel designed to run totally virtualized computers, called "boxes" (see sandbox). Currently only one "Box" is available, the ABox, that lets users run existing AmigaOS software compiled for MC680x0 and PowerPC processors.

Design goals

Quark microkernel borrows concepts from L4 microkernel family but is not an L4 implementation itself. For example the clan, id concept and recursive address mapping comes from L4. Quark also has an asynchronous/synchronous message interface similar to Amiga's Exec kernel but adapted to the memory protected environment.

Other Quark features include:

• High Super/Usermode switch speed
• Low interrupt latency
• IntThreads and Int P-code abstraction
• Symmetrical multiprocessing (SMP)
• Task/Thread and Clan/Chief model
• Resource tracking
• Virtual memory (optional)
• Distributed computing
• No access to kernel structures
• Clean design with an elegant API
• Micro/pico kernel mixture

For this new kernel a hardware abstraction layer is used which provides the necessary hardware resource information like scanning all zorro boards, PCI boards and local hardware resources.^[1][2]

Functions

SYS_AddLinkMessage SYS_AttemptSemaphore SYS_AttemptSemaphoreShared SYS_CopyCPUHalConfig SYS_CreateMemList SYS_CreateTask SYS_DeletePort SYS_DeleteSemaphore SYS_DumpMemHeader SYS_FindFreeMemArea SYS_FindSkipSize SYS_GetLinkMessage SYS_GetMessageAttr SYS_GetNextCPU SYS_Init SYS_InsideClan SYS_IsClanMember SYS_MMUAddPage SYS_MMUGetEntry SYS_MoveRomModuleToMemoryEnd

SYS_ObtainPort SYS_ObtainSemaphore SYS_ObtainSemaphoreShared SYS_ReleaseSemaphore SYS_ReplyMessage SYS_SendMessage SYS_SetMessageAttr SYS_SetupPageTable SYS_ShowExceptionThreads SYS_ShowForbidThreads SYS_ShowIntThreads SYS_ShowQuarkState SYS_ShowReadyThreads SYS_ShowRunThreads SYS_ShowThreads SYS_ShowWaitIntThreads SYS_ShowWaitThreads SYS_Start SYS_StartNextThread SYS_StartThread SYS_WaitPort

Trance JIT

Trance JIT is a MorphOS JIT compiler, or code translator, for running 68k applications within the MorphOS environment. It has been part of the MorphOS operating system since MorphOS 1.4.^[3]

MorphOS itself has a fully integrated 68k emulator for running many Amiga applications, which were almost exclusively compiled for the 68k processor, while MorphOS itself is PowerPC. Trance supplements this functionality by adding JIT compilation, increasing the speed of the emulation. It does not interfere with the full integration of 68k and PowerPC tasks MorphOS provides.^[4]

Trance exists in the form of an executable, run during boot, and a shared library. Although it is not technically part of the kernel, and MorphOS can be run without it, Trance is considered a fundamental part of MorphOS and one of its most powerful features.

Compatibility of Trance is considered to be very high and there are few to no 68k instruction sequences or applications which cause it any problems. It is also considered to be very fast, with users noticing few differences between 68k programs and native PowerPC code. ^[5][6][7]

Trance was developed by Ralph Schmidt and Teemu Suikki, with minor support from other MorphOS team members, Mark Olsen, Sigbjørn Skjæret and Harry Sintonen.

ABox

Under the Quark kernel a PowerPC native reimplementation of the OS known from the Commodore A1000, A500(+), A600, A2000, A1200, A3000(T) and A4000(T) systems runs as a mixture of a virtual emulation and a driver. This OS driver is called as ABox.

The 68k emulation is written in C and uses gcc assembler macros where necessary to speed up certain complex instructions.

A JIT (Just In Time) engine called Trance for MorphOS to speed up old 68k programs beyond the current state of the traditional emulation is also available.

The PPC native Exec supports the PowerPC register model which means there's no difference for this Exec if it runs 68k or PowerPC code. PowerPC code does not block multitasking inside the OS box like in emulations where the 68k code is just emulated in some host system's task (then every access outside this environment would stop the multitasking in the emulated environment).

For applications running under this new PowerPC ABox kernel 68k code runs as subroutines inside PowerPC tasks. For 68k or PowerPC applications it's completely transparent if some library, hook, interrupt is still 68k or already using PowerPC code.^[8]

References

1. "MorphOS? What's that, then?", AmigActive, pp. 14–17, July 2000
2. David Gerber (2002). "MorphOS Full Features List" (PDF). Retrieved 2010-07-28.
3. "MorphOS 1.4 available". 9 August 2003. Retrieved 2010-07-28.
4. "MorphOS? What's that, then?", AmigActive, pp. 14–17, July 2000
5. "How fast is MorphOS?". 8 February 2003. Retrieved 2010-07-28.
6. "MorphOS 68k speed". 3 November 2002. Retrieved 2010-07-28.
7. "Comparatif : performances entre AmigaOS 4.1 et MorphOS 2.3 sur Pegasos II (French)". September 2009. Retrieved 2010-07-28.
8. "MorphOS Full Features List". 11 December 2002. Retrieved 2010-07-28.