Subversion Repositories HelenOS-doc

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  <title>Architecture overview</title>

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    <para>The HelenOS operating system is designed as a relatively small

    microkernel assisted with a set of userspace drivers and server tasks.

    HelenOS is not very radical in what subsystems should or should not be

    implemented in the kernel - in some cases, both kernel and userspace

    drivers exist. The reason for creating the system as a microkernel is

    prosaic. Even though it is initially more difficult to get the same level

    of functionality from a microkernel than it is in the case of a simple

    monolithic kernel, a microkernel is much easier to maintain once the

    pieces have been put to work together. Therefore, the kernel of HelenOS,

    as well as the essential userspace libraries thereof can be maintained by

    only a few developers who understand them completely. In addition, a

    microkernel based operating system reaches completion sooner than

    monolithic kernels as the system can be used even without some traditional

    subsystems (e.g. block devices, filesystems and networking).</para>

    <para>HelenOS is comprised of the kernel and userspace server tasks. The

    kernel provides scheduling, memory management and IPC. It also contains

    essential device drivers that control the system clock and other devices

    necessary to guarantee a safe environment. Userspace communicates with the

    kernel through </para>

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