[PATCH v3 00/15] Add support for MediaTek MT7621 SoC

[Weijie Gao]

On Sun, 2022-05-01 at 08:52 -0400, Tom Rini wrote:
> On Sat, Apr 30, 2022 at 03:48:04PM +0200, Marek Behún wrote:
> > On Sat, 30 Apr 2022 21:31:15 +0800
> > Weijie Gao <weijie.gao at mediatek.com> wrote:
> > 
> > > On Fri, 2022-04-29 at 17:13 +0200, Marek Behún wrote:
> > > > On Fri, 29 Apr 2022 15:59:44 +0800
> > > > Weijie Gao <weijie.gao at mediatek.com> wrote:
> > > >   
> > > > > On Fri, 2022-04-29 at 08:15 +0200, Stefan Roese wrote:  
> > > > > > Hi Weijie
> > > > > > 
> > > > > > On 4/29/22 03:23, Weijie Gao wrote:    
> > > > > > > Hi Marek,
> > > > > > > 
> > > > > > > Yes. MT7621 does need such a proprietary binary for DDR
> > > > > > > initialization
> > > > > > > and calibration. That's why I submit only the ram-
> > > > > > > bootable part
> > > > > > > here.
> > > > > > > 
> > > > > > > I'm considering to create a preloader to load and run DDR
> > > > > > > init&calib
> > > > > > > binary and ram-bootable u-boot image. The ram-bootable u-
> > > > > > > boot
> > > > > > > image
> > > > > > > can be appended to the proloader to form the flash-
> > > > > > > bootable
> > > > > > > bootloader.
> > > > > > > 
> > > > > > > The source code of preloader will be uploaded to
> > > > > > > github.    
> > > > > > 
> > > > > > Just to be sure: You are not implementing this preloader as
> > > > > > an U-
> > > > > > Boot
> > > > > > SPL loader, as this would conflict with U-Boot's GPL
> > > > > > compatibility?    
> > > > > 
> > > > > Yes. Submitting the source code of this binary also violates
> > > > > MTK's
> > > > > non-
> > > > > disclosure agreement.  
> > > > 
> > > > Isn't it possible to submit the DDR training code in binary
> > > > version,
> > > > and somehow call into it from SPL?  
> > > 
> > > It's possible and I've already implemented it. But will u-boot
> > > accept
> > > binary file?
> > 
> > U-Boot at least accepts drivers that require proprietary firmware
> > to
> > load (bnxt driver, for example).
> > 
> > I don't know whether a binary firmware can be accepted into the U-
> > Boot
> > repository, whether in a separate file or as an u8 array in a .c
> > file,
> > but it should at least be possible to make it so that the user can
> > compile it thsemsevles to be bundled, i.e. create a Kconfig option
> > that
> > configures a path to the firmware. If it is present, it will be
> > compiled with DDR training bundled.
> > 
> > Stefan, Tom, can this be done?
> > 
> > BTW, Weijie, can I already test this on mt7621 board, also with DDR
> > training? Can you send me the patch that adds calling the
> > proprietary
> > code?
> 
> At the high level, I would make a further disappointed sigh and note
> the
> NXP ddr firmware blobs, the binary blobs we pull in for x86, and all
> of
> the other blobs we bring in today via binman.  Please make use of one
> of
> these otherwise existing mechanics to bring in the required DDR blobs
> here.
> 
At lease there are ways to achieve this. Thanks for the note.