Re: SMBios configuration table not present until late stage of boot

[Laszlo Ersek <lersek@redhat.com>]

On 05/19/17 12:32, Tomas Pilar (tpilar) wrote:
> The problem to solve is uniquely and persistently identifying which NICs
> are grouped together in which host to a third party management system
> over LAN during preboot in a reasonably secure way.
> 
> If we use a random generated UUID every reboot, we're not persistent. If
> we store the UUID across reboot, you could take the NIC out and move it
> to a different host and keep the ID. So the idea was to construct it
> from either the System UUID or using mobo/cpu serial numbers.

I think this platform smbios DXE driver might suffer from the
(apparently) common problem "let me do all my stuff in a ReadyToBoot
callback". To me this seems like just another example why that cannot
work, generally speaking -- a bunch of DXE drivers waiting for
"everything else" to complete their work, intending to get a "full"
system description as the last agent, and then to install stuff solely
for the OS.

This results in unspecified behavior if at least two agents with
inter-dependencies do this. Instead, the platform smbios DXE driver
should have a depex on the smbios protocol, and at dispatch time, it
should install all the tables at once (from its entry point) that are
possible to compute & install right then. I would assume type 1 is such
a table.

(just my opinion)

Thanks
Laszlo

> On 18/05/17 19:26, Laszlo Ersek wrote:
>> On 05/18/17 17:28, Tomas Pilar (tpilar) wrote:
>>> This is what I was afraid of. I am writing an IHV network driver that
>>> lives in optionROM.
>> Out of curiosity, if you can share it, what do you need the sytem UUID
>> in a network driver for?
>>
>> Thank you,
>> Laszlo
>>
>>> Cheers,
>>> Tom
>>>
>>> On 18/05/17 16:25, Jim.Dailey@dell.com wrote:
>>>> It is a tricky problem.
>>>>
>>>> What I would like is for a new protocol to be defined, which should
>>>> not rely on devices, to contain certain identifying information
>>>> like this that would be useful to device drivers. It could be
>>>> created early in DXE.
>>>>
>>>> What I fear is some future requirement that SMBIOS be made available
>>>> at some definitive time pre-OS boot.
>>>>
>>>> You may have to get support from the BIOS vendor. If you are doing a
>>>> driver for a particular system, that might not be too bad of a
>>>> solution; but if you're trying to develop some generic driver, I
>>>> don't have a good suggestion.
>>>>
>>>> Regards,
>>>> Jim
>>>>
>>>> -----Original Message-----
>>>> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of
>>>> Tomas Pilar (tpilar)
>>>> Sent: Thursday, May 18, 2017 10:14 AM
>>>> To: Dailey, Jim <Jim_Dailey@Dell.com>
>>>> Cc: edk2-devel@lists.01.org
>>>> Subject: Re: [edk2] SMBios configuration table not present until late
>>>> stage of boot
>>>>
>>>> This does make sense. Do you have a suggestion how I would go about
>>>> finding/creating a unique identifier for the system during preboot?
>>>>
>>>> Cheers,
>>>> Tom
>>>>
>>>> On 18/05/17 16:11, Jim.Dailey@dell.com wrote:
>>>>> Not a helpful comment, but I wanted to air my feelings on the topic:
>>>>>
>>>>> I view SMBIOS as data strictly for OS-level consumption and not for
>>>>> any pre-boot code.  I'm sure I'm in the minority, however.
>>>>>
>>>>> One of the problems is that the BIOS needs to have scanned all
>>>>> devices/resources and perhaps executed a connect all before the
>>>>> tables can be generated (or at least completed).
>>>>>
>>>>> Regards,
>>>>> Jim
>>>>>
>>>>> -----Original Message-----
>>>>> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf
>>>>> Of Tomas Pilar (tpilar)
>>>>> Sent: Thursday, May 18, 2017 10:01 AM
>>>>> To: edk2-devel@lists.01.org
>>>>> Subject: [edk2] SMBios configuration table not present until late
>>>>> stage of boot
>>>>>
>>>>> Hi,
>>>>>
>>>>> I am trying to read the system UUID from the System Table (Type 1) in
>>>>> the SMBios set of tables. I am doing this during DriverBinding.Start()
>>>>> part of the UEFI_DRIVER initialisation. Unfortunately the
>>>>> gST->ConfigurationTable only contains 6 tables and SMBios is not
>>>>> one of
>>>>> them.
>>>>>
>>>>> Once I boot into UEFI shell or start a PXE booting process, the
>>>>> gST->ConfigurationTable now contains 8 tables and SMBios is one of the
>>>>> two new tables. If I however only boot to a HDD, this never seems to
>>>>> happen.
>>>>>
>>>>> Can someone offer some insight why this might be so and how would I go
>>>>> about forcing the platform to provide the SMBios in
>>>>> gST->ConfigurationTable at a sensible point?
>>>>>
>>>>> Incidentally it seems ExitBootServices is not signaled on this
>>>>> platform
>>>>> if the boot goes through to HDD either, which is another strange
>>>>> thing ...
>>>>>
>>>>> Cheers,
>>>>> Tom
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
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