Re: [RFC PATCH v4 14/15] arm/Kconfig: Always select SEMIHOSTING when TCG is present

[Fabiano Rosas <farosas@suse.de>]

Philippe Mathieu-Daudé <philmd@linaro.org> writes:

> On 19/1/23 19:50, Richard Henderson wrote:
>> On 1/19/23 03:54, Fabiano Rosas wrote:
>>> We are about to enable the build without TCG, so CONFIG_SEMIHOSTING
>>> and CONFIG_ARM_COMPATIBLE_SEMIHOSTING cannot be unconditionally set in
>>> default.mak anymore. So reflect the change in a Kconfig.
>>>
>>> Instead of using semihosting/Kconfig, use a target-specific file, so
>>> that the change doesn't affect other architectures which might
>>> implement semihosting in a way compatible with KVM.
>>>
>>> The selection from ARM_v7M needs to be removed to avoid a cycle during
>>> parsing.
>>>
>>> Signed-off-by: Fabiano Rosas<farosas@suse.de>
>> 
>> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
>> 
>>> The linux-user build does not use Kconfig. Is it worth it to add
>>> support to it? There's just the semihosting config so far.
>> 
>> Probably not.
>
> I hit this limitation last week trying to restrict libdecnumber to
> powerpc targets.
>
> Fabiano, do you see how this can be done easily?

If you grep for Kconfig in the top level meson.build, that code there
could be adapted to also include linux-user targets.

I did some experimenting and I could generate linux-user.mak files with
all the configs from the existing Kconfigs. It would be a matter of
adding the proper CONFIG_SOFTMMU, CONFIG_LINUX_USER options to separate
the two and then hooking up the .mak files with the rest of the
build. That last part I'm not sure how to do.