Re: [coreboot] Maintain boot order for multiple EFI based OS

[Zoran Stojsavljevic]

> Current UEFI payload uses an generic emulated variable driver provided in

EDK2 MdeModulePkg.

Thank you for that info, Maurice. Was looking for this (right entry point)
for very long time! :-)

Zoran

On Thu, Mar 23, 2017 at 1:56 AM, Ma, Maurice  wrote:
> Hi, Sibi，
>
> Yes,  UEFI payload follows the same way as standard UEFI FW on boot order
> handling.   You will have to enable a NVRAM variable driver in order to
> maintain the boot options and order.
>
> Current UEFI payload uses an generic emulated variable driver provided in
> EDK2 MdeModulePkg.   With this driver, the variable will be lost after
> reboot since it is stored in memory.
>
> To  store it in NVRAM,  you will then need to develop or port a flash
> based variable driver, and then replace the emulated variable driver.  This
> part is very platform and silicon specific.
>
> Thanks
>
> Maurice
>
> *From:* Leahy, Leroy P
> *Sent:* Wednesday, March 22, 2017 4:51 PM
> *To:* [e-mail]; [e-mail]; Ma, Maurice <
> [e-mail]>; Agyeman, Prince 
> *Subject:* Re: Maintain boot order for multiple EFI based OS
>
> Hi Maurice and Prince,
>
> Would you please help answer the question below?
>
> Hi Sibi,
>
> The maintainers for the various EDK-II packages can be found in
> payloads/external/tianocore/tianocore/Maintainers.txt.  In your case,
> search for CorebootPayloadPkg.
>
> Lee Leahy
>
> *From:* coreboot [mailto:[e-mail]
> ] *On Behalf Of *[e-mail]
> *Sent:* Wednesday, March 22, 2017 6:20 AM
> *To:* [e-mail]
> *Subject:* [coreboot] Maintain boot order for multiple EFI based OS
>
> *Dell - Internal Use - Confidential *
>
> Hi,
>
> We are using the coreboot project with Intel fsp to boot the Intel
> Rangeley based Mohonpeak CPU. We have built the Tianocore EDK2 project and
> used it as the payload to bring UEFI services to this bootloader. With this
> payload, we are able to boot a EFI based OS successfully.
>
> As a next step, we are looking at installing multiple EFI OS and
> maintaining boot order among the OS.
>
> How is boot order maintained with UEFI payload?
>
> Is it through EFI NVRAM variables? If so, does coreboot support NVRAM
> variables?
>
> Can you please point us in the right direction.
>
> Thanks,
>
> Sibi