[U-Boot] Booting imx_4.14.98_2.0.0_ga on i.MX8QM MEK Board

[Marcel Ziswiler]

Hi Peng

On Thu, 2019-05-02 at 03:57 +0000, Peng Fan wrote:
> Hi Marcel,
> 
> > Subject: Booting imx_4.14.98_2.0.0_ga on i.MX8QM MEK Board
> > 
> > Hi Peng, Stefano and Fabio
> > 
> > We are currently trying to boot the Linux kernel from NXP's
> > downstream Linux
> > BSP 4.14.98_2.0.0_ga with mainline U-Boot. However, that currently
> > seems
> > to crash as follows:
> > 
> > ...
> > 
> > Does any of you know what exactly could be going on?
> 
> SMMU is not powered up, so smmu driver probe triggers abort when
> accessing
> SMMU registers. Need power up SC_R_SMMU.

I see, this is actually done in downstream U-Boot:

https://source.codeaurora.org/external/imx/uboot-imx/commit/?h=imx_v2018.03_4.14.98_2.0.0_ga&id=45308e7da90f342c2de7fbec1f8c5b8bd3f1b8e5

Wondering how that is supposed to work with mainline U-Boot at the end.

> > BTW: The exact same crash is observed on Apalis iMX8 as well, while
> > both the
> > i.MX8QXP MEK as well as Colibri iMX8QXP boot that same downstream
> > Linux
> > kernel just fine. Must be something i.MX 8QuadMax specific...
> 
> There is no SMMU on i.MX8QXP.

Funny, at least in downstream U-Boot the same SMMU setup is done (;-p).

> Regards,
> Peng.

Thanks, Peng!

> > Cheers
> > 
> > Marcel

Cheers

Marcel