On 02/23/2015 04:55 PM, James Bottomley wrote:
> On Wed, 2015-02-18 at 23:32 -0800, Andrew Fish wrote:
>>> On Feb 18, 2015, at 11:19 PM, Sergey Isakov <[email protected]> wrote:
>>>
>>> No, memory change is not event for hardware. It is not interrupt
>>> as well. No matter of UEFI or not.
>>>
>>
>> From a hardware point of view you could make the page write protected
>> and take a page fault on the write.
>
> Please don't do this: I don't think handling interrupts in UEFI is
> something we want to get into. What happens at runtime when the OS is
> supposed to be handling all the interrupts? ... the UEFI standard
> defines no mechanism for handing off interrupts from the OS to the UEFI
> layer (assuming the OS even determines that's where they belong).
At runtime, the OS will control the interrupt vector table, so you will
need to use something in the OS to handle it. The BIOS's exception
handlers are gone at that point.
But handling interrupts in UEFI firmware isn't that hard: debuggers do
it all the time (see SourceLevelDebugPkg.) And
UefiCpuPkg/Library/CpuExceptionHandlerLib gives a standardized way to
register interrupt handlers within the UEFI environment. (Technically,
that library is a PI spec thing, I believe....) You could make a page
write protected, or set up a watchpoint in the the debug registers to
catch writes to that particular address. Then do whatever you need to
do in the corresponding exception handler. Not that it would be
trivial, but it would at least be possible.
--
Brian
--------------------------------------------------------------------
"You have greater impact on others by the way you listen than by the
way you talk."
-- Unknown
------------------------------------------------------------------------------
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the
conversation now. http://goparallel.sourceforge.net/
_______________________________________________
edk2-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/edk2-devel
