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Quark
Developer	Ralph Schmidt, Teemu Suikki
Written in	C, assembly language
OS family	AmigaOS
Working state	Current
Marketing target	Amiga
Available in	English
Update method	Compile from source code
Platforms	Motorola 68000 series (MC680x0, 68k),; PowerPC (PPC)
Kernel type	Microkernel
Default; user interface	Command-line interface
Preceded by	AmigaOS

In computing, Quark is an operating system kernel used in MorphOS. It is a microkernel designed to run fully virtualized computers, called boxes (see sandbox). As of 2020^[update], only one box is available, the ABox, that lets users run extant AmigaOS software compiled for Motorola 68000 series (MC680x0 or 68k) and PowerPC central processing units (CPUs).

Design goals

The Quark microkernel is not a member of the L4 microkernel family, but borrows concepts from it, including: the clan (group of tasks), ID concept, and recursive address mapping. Quark also has an asynchronous/synchronous message interface similar to Amiga's Exec kernel but adapted to an environment with memory protection.

Other Quark features include:

High super/usermode switch speed
Low interrupt latency
Interrupt threads (IntThreads) and Int P-code abstraction
Symmetric multiprocessing (SMP)
Models task/thread and clan/chief
Resource tracking
Virtual memory (optional)
Distributed computing
No access to kernel structures
Clean design with an elegant application programming interface (API)
Micro/pico kernel mix

For this new kernel, a hardware abstraction layer is used which provides the needed hardware resource information like scanning all Amiga Zorro II bus boards, Peripheral Component Interconnect (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 just-in-time (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 has a fully integrated 68k emulator to run many Amiga applications, which were almost exclusively compiled for the 68k processor, though MorphOS runs on PowerPC. Trance supplements this function by adding JIT compiling, increasing the speed of the emulation. It does not interfere with the full integration of 68k and PowerPC tasks MorphOS provides.^[1]

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.^[4]^[5]^[6]

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 International A1000, A500(+), A600, A2000, A1200, A3000(T), and A4000(T) systems runs as a mix of a virtual emulation and a driver. This OS driver is called an ABox.

The 68k emulation is written in C and uses GNU Compiler Collection (GCC) assembly language macros where needed to speed up some complex instructions.

A JIT engine named Trance is also available for MorphOS, to speed up old 68k programs beyond the current state of the traditional emulation.

The PPC native Exec supports the PowerPC register model which means there is 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 fully transparent if some library, hook, interrupt is still 68k or already using PowerPC code.^[7]

References

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