testbios and the system timer
Eric W. Biederman
ebiederman at lnxi.com
Tue Jun 8 11:33:01 CEST 2004
Richard Smith <rsmith at bitworks.com> writes:
> Eric W. Biederman wrote:
>
> >> You can in the emulator redirect I/O port access to a function. Write the
> >> code to handle read/write on those ports and use the emulate_counter to drive
>
> >> the clock value.
> > Let me ask this quick question. Does the emulator restrict port I/O to
> > just the resources on a particular VGA device? If not that is something
> > we need to do to implement to ensure we flush these kinds of issues
> > into the open and ensure the emulator is portable.
>
> No. It allows full access to all IO ports. Otherwise it would have never been
> able to get to the system timer.
I was afraid of that.
> So not only will it have to emulate x86 instructions it will have to emulate
> some of the generic x86 hardware setup.
Exactly. But in this case emulation is more predictable than making
certain your hardware is setup in a legacy conforming mode.
Eric
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