Re: Question about memory map entries

[Rafael Machado <rafaelrodrigues.machado@gmail.com>]

Thanks Andrew and Laszlo for the clarification and guidance.

About Laszlo questions

>Is the reboot automatic (from the platform firmware), or application /
>user initiated?
Yes. We just do some clean up, finish the events and "return EFI_SUCCESS;"

>Do you exit the application before the system is powered off?
No. At this test we just let the application finishes it's work and power
off the system.  No "return EFI_SUCCESS;"

Thanks and Regards
Rafael

Em qui, 2 de ago de 2018 às 11:44, Laszlo Ersek <lersek@redhat.com>
escreveu:

> On 08/02/18 14:39, Rafael Machado wrote:
> > Hi everyone
> >
> > After some other tasks I am back to this case :)
> >
> > After some debug, we detected the moment where things start to go wrong,
> > but I am not sure what may cause this.
> >
> > What we noticed is that the following assert is reached:
> >
> https://github.com/tianocore/edk2/blob/87acb6e298e718250dd8b741b6888a3a54c7cb5a/MdeModulePkg/Core/Dxe/Gcd/Gcd.c#L2199
> >
> > Just to remember, this assert is reached with the following steps:
> > 1 - Boot the application (renamed to BOOTX64.efi) from a usb stick
> > 2 - Execute the application tasks
> > 3 - exit the application (free everything, all events closed and  no
> memory
> > leaks detected as suggested to check by Andrew on the previous e-mail,
> then
> > return efi_success)
> > 4 - the system will reboot and reach the assert
>
> Is the reboot automatic (from the platform firmware), or application /
> user initiated?
>
> > But it does not happen with the following scenario:
> > 1 - Boot the application (renamed to BOOTX64.efi) from a usb stick
> > 2 - Execute the application tasks
> > 3 - Power off the system
>
> Do you exit the application before the system is powered off?
>
> >
> > As far as I could understand (please correct my understanding that may be
> > wrong since is the first time I look at this part of the code), at this
> > point the HOBs passed from sec phase are processed by PEI so the memory
> > could be "detected/mapped/initialized" correctly. But for some reason the
> > required HOB is no present at the list.
> >
> > Could someone with more experience at this part of the code please
> confirm
> > my understanding, and if possible give some guesses about what could
> cause
> > this scenario?
>
> PEI may act differently (produce different HOBs) dependent on boot mode.
> The PI spec defines several boot modes; it's platform-dependent what
> hardware states / transitions are mapped to what PI boot modes by the
> firmware.
>
> > My guess is that some memory cleanup that should be done by the bios
> after
> > the application exits is not being done correctly. So I believe the
> problem
> > is not at the application, but at the BIOS. A friend here mentioned about
> > the MemoryTypeInformation efi var, that may be corrupted, and considering
> > it's used to guide the boot process it may impact the boot, but I am not
> > sure if this is the case and also I didn't find to much information about
> > this var and it's usage, so any help about this would be well received
> also.
>
> MemoryTypeInformation measures peak usage (of various UEFI memory types)
> during boot, so that at next boot, the internal allocation "bins" can be
> primed with large enough sizes. The goal is to reduce fragmentation due
> to "unforeseen" allocations.
>
> If you exit the application gracefully in both scenarios (and the only
> difference is whether you reboot the system, or power it down,
> afterwards, e.g. by passing different options to the RESET command of
> the UEFI shell), then I don't see how MemoryTypeInformation could be
> relevant.
>
> Thanks
> Laszlo
>