Re: Interrupt testing

[Vladimir 'phcoder' Serbinenko]

On Sun, Mar 8, 2009 at 2:32 PM, Robert Millan<address@hidden> wrote:
> On Sat, Mar 07, 2009 at 04:43:01PM +0100, phcoder wrote:
>> Hello. Here is a trivial patch for testing which interrupts are and
>> which aren't handled by BIOS. Can be used as a simple but not reliable
>> test for boot viruses
>
> Would it be feasible to make this more generic?  BIOS works with 16-bit 8086
> mode interrupt handlers, others might have setup 32-bit interrupt handlers.
>
> What would you think of:
>
>  - Detect both 16-bit / 8086 interrupts and 32-bit ones.
>  - Make it agnostic about what firmware instead of assuming BIOS.
>  - Building it in i386.rmk instead.
>
I don't know if it's possible. Any interrupt handler would also
intercept mmap interrupts so checking against memory map is useless.
The problem is to know which parts of memory are ROM and which ones
are RAM. I think what you propose is possible but I don't know how to
do it. The main idea behind this checker is to check for simple boot
viruses (not advanced ones) and the main target for boot viruses is
BIOS (even if EFI would be excellent for virus writers)
>  ?
>
> --
> Robert Millan
>
>  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
>  how) you may access your data; but nobody's threatening your freedom: we
>  still allow you to remove your data and not access it at all."
>
>
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-- 
Regards
Vladimir 'phcoder' Serbinenko

Personal git repository: http://repo.or.cz/w/grub2/phcoder.git