[U-Boot] UEFI on u-boot

[Udit Kumar]

Hi Alex

> -----Original Message-----
> From: Alexander Graf [mailto:agraf at suse.de]
> Sent: Monday, January 15, 2018 2:45 PM
> To: Udit Kumar <udit.kumar at nxp.com>
> 
> Hi Udit,
> 
> On 15.01.18 10:09, Udit Kumar wrote:
> > Hi Alex,
> > Hope you are doing great,
> >
> > Could you help on UEFI over the u-boot.
> > 1- I couldn't locate EFI_DXE_SERVICES in u-boot, do you have plan to
> > add those
> 
> Right now the model is that all device drivers are implemented by U-Boot
> and that only exposes their interfaces to EFI applications. Implementing DXE
> in U-Boot would open quite a big can of worms, as it would really only be
> useful in compilation with PI which is a terrible interface :).

Ok, 
 
> > 2- If I load  a driver (with bootefi) which install few protocols,  is
> > this ok to do with u-boot
> 
> It depends on how much the driver does, but in general yes. Heinrich is
> currently working on making the iPXE iSCSI driver work, so his EFI payload
> would expose an EFI block device to yet another payload running after his.

Thanks for this, 
Heinrich,  in  this driver, are you accessing underneath hardware register 
by UEFI-Driver and managing UEFI protocols
or you are relying on some h/w access exposed by u-boot driver


 
> > 3- if you say, 2 is ok then I hope these protocols are kept in some
> > data base, and this new protocol can be opened by an application
> 
> Yes, the protocol database is now global and persistent across bootefi
> invocations.

Thanks 
 
> > 4- if there is some known limitation, like we cannot run DXE_driver
> > etc
> 
> What exactly are you trying to do? With the U-Boot UEFI implementation
> we're trying to find a sweet spot between implementing as much as makes
> sense, but not the whole UEFI world, as that would just bloat the code
> needlessly.

I am trying to add a driver (DXE by definition) which 
a) Access the hardware registers. (I said DXE could due to hardware registers)
b) Update memory map as well (AddMemorySpace call)
c) Finally it export a protocol, which could be used by its test application. 

For b) I am not able to find function call, 
For a), if I say driver is UEFI and accessing hardware register, will this be acceptable ?  
 
> 
> Alex