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--  README,v 1.3 1995/12/19 20:12:30 joel Exp

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Overview of newlib support (newlib is from CYGNUS)

    Each task can have its own libc state including:

        open stdio files

        strtok

        multi precision arithmetic state

        etc.

    This is implemented by a reentrancy data structure for each task.

    When a task is "started" (in RTEMS sense) the reentrancy structure

    is allocated.  Its address is stored in notepad[NOTEPAD_LAST].

    When task is switched to, the value of global variable _impure_ptr

    is changed to the value of the new tasks reentrancy structure.

    When a task is deleted

        atexit() processing (for that task) happens

        task's stdio buffers are flushed

    When exit(3) is called

        calling task's atexit processing done

        global libc state atexit processing done

            (this will include any atexit routines installed by drivers)

        executive is shutdown

            causes a context switch back to bsp land

NOTE:

    libc extension are installed by bsp_libc_init()

        iff we are using clock interrupts.

        This hack is necessary to allow the tmtests to avoid

        timing the extensions.