[U-Boot] [RFC] efi_loader: workaround for EDK2's shell.efi

[Alexander Graf]

> Am 09.08.2018 um 09:30 schrieb AKASHI Takahiro <takahiro.akashi at linaro.org>:
> 
>> On Thu, Aug 09, 2018 at 07:55:06AM +0100, Alexander Graf wrote:
>> 
>> 
>>> On 09.08.18 07:15, AKASHI Takahiro wrote:
>>> The commit 21b3edfc964 ("efi_loader: check parameters of CreateEvent")
>>> enforces a strict parameter check at CreateEvent().  Unfortunately,
>>> however, EDK2's Shell.efi calls this function with notify_tpl == 0.
>>> 
>>> The patch above does right thing and we'd better fix the issue on EDK2
>>> side, and yet we might want a workaround allowing for running un-modified
>>> version of EDK2 in short-term solution.
>> 
>> ... of the EDK2 shell ...
>> 
>> and it's not just about short term - we always want to be compatible :).
> 
> Okay.
> 
>> So what's the reason this does not trigger in edk2? Are they considering
>> TPL 0 a valid TPL always or did they just forget the check in create
>> event? If they always consider TPL 0 valid, we better change
>> is_valid_tpl to ensure compatibility with edk2's behavior.
> 
> I'm not confident about what Shell's intent is.
> Created here is an event to be used to raise a signal for "notification
> of Ctrl-C keystrokes," and hence Shell expects such key data to always
> be sent to a task whatever its TPL is?

Leif, can you please help out here?


Thanks!

Alex