syscall-msg emulation layer help

Matthew Dillon dillon at apollo.backplane.com
Fri Jul 16 08:52:23 PDT 2004


:Carlo "vl4d" Comin wrote:
:
:> is anyone already working on userapi?
:
:can someone consider to answer, please? :)

    Hey, I only have 500 unread emails in my mailbox!

    Nobody is working on this yet, but the concepts are pretty well
    laid out.  Doing it right, however, is going to require both
    userland and kernelland coding skills.

    The general idea is to have a kernel-managed 'emulation layer' space
    that is up in kernel memory and managed by the kernel but is also
    read/exec from userland.  This emulation layer would take over the
    standard system call space and convert system calls to system call
    messages, then use the sysmsg facility in the kernel to dispatch
    the message and wait for the result.

    'Newer' programs would be aware of this space and be able to call into
    it directly.  So in the sense of DFly-native programs, the emulation
    layer would act more like a shared library (though in reality it would
    not be).

    Since the emulation space would be using the messaging interface, it
    would be thread-safe.

    The idea is then to have an emulation space for the freebsd4 syscalls,
    freebsd5, linux, sysv, ibcs, etc.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>





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