Re: [PATCH 00/17] arm: semihosting: Cleanups and new features

[Andre Przywara <andre.przywara@arm.com>]

On Fri, 4 Mar 2022 02:06:03 +0100
Linus Walleij <linus.walleij@linaro.org> wrote:

Hi,

Linus, thanks for the heads up, much appreciated!

> On Thu, Mar 3, 2022 at 9:44 PM Sean Anderson <sean.anderson@seco.com> wrote:
> 
> > The main device affected by these changes is vexpress64, so I'd appreciate
> > if Linus (or anyone else) could try booting.  

As it happens, I am sitting on a series updating vexpress_aemv8a_semi, and
letting it use OF_CONTROL. I will send this ASAP.
As it turned out, the automatic semihosting boot command is actually broken
in v2022.01, the fix is the first patch in my series. This clashes with
this series, but it's easy to resolve.

From skimming over this series here, it looks quite nice, I especially love
promoting the semihosting load to a proper filesystem. The only drawback
seems to be that this will break existing scripts used by people in their
deployments, which rely on the smhload command. I don't really know if
there are actually any users doing so, but I guess we will find out.

Is there any official U-Boot policy for changing commands, which might
break scripts? For instance I was always tempted to fix the "afs" command,
or make that an fs as well.

I will test and review this series ASAP.

Thanks,
Andre

> 
> I am currently on parental leave and pretty far removed from that hardware
> and have very little bandwidth. I added Andre Przywara to the header
> (include him in the future) because currently he does much more U-Boot
> work on these platforms than me.
> 
> The actual user of the semihosting commands is (IIRC) FVP, the software-only
> version of vexpress-variants. The semihosting creates software traps
> inside the emulated environment.
> 
> Yours,
> Linus Walleij