[U-Boot] A80 (CubieBoard4) u-boot - what to inject in boot0 area?

[Chen-Yu Tsai]

"Hi,

On Tue, Jul 18, 2017 at 10:40 AM, Konrad Rzeszutek Wilk
<konrad at kernel.org> wrote:
> Hey,
>
> I am trying to install an U-boot from the upstream repo as it looks to have most (if not all?)
> of the features needed for the A80 board (Cubieboard4).
>
> I've built the uboot just fine (using the default ./configs/Cubieboard4_defconfig)
> ..
> ./tools/mkimage -A arm -T firmware -C none -O u-boot -a 0x2a000000 -e 0 -n "U-Boot 2017.07-00217-ge14b116 for sunxi board" -d u-boot.bin u-boot.img
> Image Name:   U-Boot 2017.07-00217-ge14b116 fo
> Created:      Wed Jul 12 22:11:53 2017
> Image Type:   ARM U-Boot Firmware (uncompressed)
> Data Size:    355711 Bytes = 347.37 KiB = 0.34 MiB
> Load Address: 2a000000
> Entry Point:  00000000
>
> And now I am trying to load it on the SD card and load it
> on a Cubieboard4, but it just hangs.
>
> If I use from the CC-A80-binaries[*1] git repo the "sdcard-fwbuild.sh"
> and put the two resulting binaries on the SD card it boots fine.
>
> But naturally the u-boot that is on the mentioned repo is from 2011
> and I would like a more recent version.
>
> If I try to use the CC-A80-binaries[*1] git repo and the "sdcard-fwbuild.sh"
> with the upstream u-boot it complains very loudly - and the resulting
> binary is not created.
>
> I figured out that it must be due to the header which as the magic
> string of 'uboot' (which in [*2] is in arch/arm/cpu/armv7/sun9iw1/spare_head.c)
>
> In u-boot upstream I can set CONFIG_RESERVE_ALLWINNER_BOOT0_HEADER=y
> which I did, but now I am struggling to figure out what I am
> suppose to put in there. Any ideas? Is there an tool to fill this
> area out? And more importantly, am I on the right track or is
> there something else that I a missing?
>
> I did look at board/sunxi/README.sunxi64 and it explained about the boot0
> but that talks about A53 boards I have an A15 (armv7) - and
> 'arm-trusted-firmware' is all geared towards armv8.
>
> Hints of what I should do next?

With ARMv7 Allwinner SoCs and mainline U-boot, boot0 is replaced with
U-boot SPL. The build process should generate a "u-boot-sunxi-with-spl.bin"
file, which is the SPL combined with U-boot proper at the correct offsets.
Just write that as you would the image built from "sdcard-fwbuild.sh",
that is at an offset of 8192 bytes on the SD card.

ChenYu

>
> Thanks!
>
> [*1]: https://github.com/cubieboard/CC-A80-binaries
> [*2]: https://github.com/cubieboard/CC-A80-u-boot
>