[U-Boot] [PATCH v2 1/2] ARC: HSDK: add platform-specific commands

[Alexey Brodkin <Alexey.Brodkin@synopsys.com>]

Hi Tom,

On Mon, 2018-03-26 at 15:57 +0300, Eugeniy Paltsev wrote:
> This patch add support of hsdk platform-specific commands:
> 
> hsdk_clock set - set clock from axi_freq, cpu_freq and tun_freq
> environment variables/command line arguments
> 
> hsdk_clock get - save clock frequencies to axi_freq, cpu_freq
> and tun_freq environment variables
> 
> hsdk_clock print - show CPU, AXI, DDR and TUNNEL current
> clock frequencies.
> 
> hsdk_clock print_all - show all currently used clock frequencies.
> 
> hsdk_init - setup board HW in one of pre-defined configuration
> (hsdk_hs34 / hsdk_hs36 / hsdk_hs36_ccm / hsdk_hs38 /
> hsdk_hs38_ccm / hsdk_hs38x2 / hsdk_hs38x3 / hsdk_hs38x4)
> 
> hsdk_go - run baremetal application on hsdk configured
> by hsdk_init command.
> 
> This patch changes default behaviour of 'bootm' command:
> now we are able to set number of CPUs to be kicked by setting
> 'core_mask' environment variable before 'bootm' command run.
> 
> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
> ---

I was about to send you a pull-request containing this one but
decided to give TravisCI a shot. And what I got was a warning
due to not yet supported "naked" attribute in GCC 6.x for ARC,
see https://travis-ci.org/abrodkin/u-boot/jobs/360259472

Ok I bumped ARC tools to the most recent arc-2017.09 based on
GCC 7.1 where "naked" attr for ARC is already supported.
But then I got another warning:
--------------------->8-----------------------
board/synopsys/hsdk/hsdk.c: In function "hsdk_core_init_f":
board/synopsys/hsdk/hsdk.c:345:1: error: stack usage computation not supported for this target [-Werror]
 }
 ^
--------------------->8-----------------------
see https://travis-ci.org/abrodkin/u-boot/jobs/360274604


That happens because GCC for ARC unconditionally tries to compute
stack requirements for all functions even if they are "naked".
And for "naked" computed value is negative thus the warning above.

So far I didn't manage to find a simple way to disable that warning.

And my question would be how to proceed with this [patch]?
Given we're seeing a problem in GCC it most probably won't be fixed
in U-Boot and we'll need to wait before new tools are available.

Or otherwise we'll start to see "failing" ARC jobs in TravisCI.

-Alexey