kwboot: UART booting with bin_hdr u-boot (Marvell Armada 385)

[Pali Rohár]

On Wednesday 04 January 2023 08:50:28 Pali Rohár wrote:
> Hello!
> 
> On Tuesday 03 January 2023 17:55:41 Tony Dinh wrote:
> > Hi Pali,
> > 
> > I'm building a new u-boot for the Thecus N2350 board (Armada 385
> > dual-core 1Ghz 1GB DDR4). The trouble with this board is DDR4, which
> > is not currently supported in u-boot (also cc this to Chris for
> > commenting about Marvell DDR4 training driver).
> 
> Yes, ddr4 training code is not in u-boot yet.
> 
> A38x u-boot ddr driver is in this directory:
> https://source.denx.de/u-boot/u-boot/-/tree/master/drivers/ddr/marvell/a38x
> 
> And it is copied from the original marvell driver by stripping non-a38x
> code and removal of the ddr4 code from the master branch:
> https://github.com/MarvellEmbeddedProcessors/mv-ddr-marvell
> 
> So you can try to copy code again without stripping ddr4 parts
> (run git log drivers/ddr/marvell/a38x in u-boot)

https://source.denx.de/u-boot/u-boot/-/commit/107c3391b95bcc2ba09a876da4fa0c31b6c1e460

> And adjust u-boot board code for ddr4.
> 
> I guess it could work but it would be needed to play with it.
> 
> > So I'm building with binary.0 in the ./board/thecus/n2350/. This
> > binary.0 is a copy of the Marvell bin_hdr for SPI in the GPL source
> > for this board (provided by Thecus). My
> > ./board/thecus/n2350/kwbimage.cfg.in file looks like this
> > 
> > # Armada 38x uses version 1 image format
> > VERSION         1
> > # Boot Media configurations
> > BOOT_FROM spi
> > # Binary Header (bin_hdr) with DDR4 training code
> > BINARY board/thecus/n2350/binary.0 0000005b 00000068
> > 
> > When I kwboot the u-boot.kwb image (using kwboot binary built with
> > 2023.01-rc4), the header was transferred successfully, but then the
> > BootROM jumped to SPI u-boot, instead of loading the u-boot payload
> > from UART. Please see the log below.
> > <BEGIN LOG>
> > # ./kwboot -t -p -B 115200 /dev/ttyUSB0 -b uboot.kwb
> > 
> > kwboot version 2023.01-tld-1-00048-g19e15f9081-dirty
> > Patching image boot signature to UART
> > Aligning image header to Xmodem block size
> > Sending boot message. Please reboot the target.../
> > Sending boot image header (97792 bytes)...
> >   0 % [......................................................................]
> >   9 % [......................................................................]
> > <snip>
> >  82 % [......................................................................]
> >  91 % [................................................................      ]
> > Done
> > 
> > BootROM - 1.73
> > Booting from SPI flash
> 
> This indicates reset of the board. BootROM started execution of the
> image from the primary location.
> 
> > <snip>
> > U-Boot 2013.01 (Nov 12 2018 - 20:56:19) Marvell version: 2015_T1.0p18-tld-4
> > <END LOG>
> > 
> > It seems kwboot patched the image, but the BOOT_FROM indicator was
> > still recognized as from SPI. So the BootROM loaded the stock u-boot
> > image from SPI and executed it. Since I am booting with bin_hdr, I'm
> > not sure if there is something inside this blob that has forced this
> > indicator to SPI.
> 
> No, blob cannot force BootROM to switch boot location. This really
> indicates crash of the blob or crash of the payload which results in the
> board reset.
> 
> > I'm attaching the u-boot.kwb image to this email, in case you are
> > interested in taking a look at the structure.
> > 
> > Thanks,
> > Tony
> 
>