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

[Chris Packham]

On Wed, 4 Jan 2023, 8:52 PM Pali Rohár, <pali at kernel.org> wrote:

> 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.
>

Last time I looked the MarvellEmbeddedProcessors stuff was a long way
behind what Marvell are releasing to customers. That was for the newer SoCs
so maybe the A385 stuff is current.

>
> > > 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
> >
> >
>