serial download on imx8mp

[Peng Fan (OSS)]

On 2021/10/22 15:37, Rasmus Villemoes wrote:
> Hi
> 
> I'm having trouble getting serial download to work on an imx8mp evk. I'm
> building on top of v2021.10.
> 
> The SPL + U-Boot proper that I build work fine when I write them to an
> SD card and boot from that, also boot from eMMC with the same binaries
> works fine.
> 
> I can also succesfully get the SPL to load and run via USB, and I can
> _partially_ load the u-boot.itb; in the sense that I can see that
> bl31.bin runs: I get the lines
> 
> NOTICE:  BL31: v2.4(release):lf-5.10.52-2.1.0-rc1-39-gbb4957067
> NOTICE:  BL31: Built : 04:45:39, Sep  8 2021
> 
> on the serial console (same as when happens when booting via sd or
> emmc), but then the board just hangs.

DDR init pass, right?
Do you have a jtag to debug? THis board supports openOCD, you could give 
a try.

bl31 boots up and no more log, it is hard to tell where the issue is.

Better confirm whether bl31 jumps to U-Boot.

Regards
Peng



> 
> Now, extracting the u-boot.itb from the
> imx-boot-imx8mpevk-sd.bin-flash_evk file I found inside
> LF_v5.10.52-2.1.0_images_IMX8MPEVK.zip, I can actually get _that_
> u-boot.itb to run on top of the SPL that I built, so I think my SPL is
> alright (after all, it does manages to hand control over to BL31). That
> u-boot.itb is
> 
>    U-Boot 2021.04-lf_v2021.04+g1c0116f3da
> 
> Vanilla v2021.04 shows the same symptoms of being unable to boot via
> serial download. So I did a bisect between v2021.04 and 1c0116f3da. That
> bisect lands at
> 
> commit 3a053a1bd6bc03eaffe82648a318b065d70d1bd0 (refs/bisect/boots)
> Author: Ye Li <ye.li at nxp.com>
> Date:   Tue Apr 21 20:14:29 2020 -0700
> 
>      MLK-23574-39 imx8mp_evk: Update iMX8MP EVK board codes
> 
> so I suppose _something_ in that commit fixed it, but unfortunately
> 
>   board/freescale/imx8mp_evk/imx8mp_evk.c | 332
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>   board/freescale/imx8mp_evk/spl.c        |  79 ++++++++++++-------------
>   configs/imx8mp_evk_defconfig            |  66 +++++++++++++++++++--
>   include/configs/imx8mp_evk.h            | 156
> ++++++++++++++++++++++++++++++++++++++++++-------
>   4 files changed, 561 insertions(+), 72 deletions(-)
> 
> means I have no idea what part of it is missing in mainline, or if there
> are more bits and pieces scattered around that are prerequisites for
> getting it to work.
> 
> But it's really odd, because once the entire image has been downloaded,
> the components of the FIT have been loaded to the proper addresses and
> control handed over to BL31, I don't see how U-Boot proper (the very
> same binary that's used when booting from sd or emmc) can fail, and
> U-Boot shouldn't really need to know or care about where it was loaded from.
> 
> Rasmus
>