[PATCH] efi_loader: Allow disabling ANSI console queries via env variable

[Michal Simek]

On 3/17/26 08:43, Ilias Apalodimas wrote:
> Hi Michal
> 
> On Mon, 16 Mar 2026 at 09:45, Michal Simek <michal.simek at amd.com> wrote:
>>
>> Hi Heinrich and Ilias,
>>
>> On 3/16/26 03:43, Simon Glass wrote:
>>> Hi,
>>>
>>> On Fri, 13 Mar 2026 at 09:50, Michal Simek <michal.simek at amd.com> wrote:
>>>>
>>>>
>>>>
>>>> On 3/13/26 16:47, Peter Robinson wrote:
>>>>> On Fri, 13 Mar 2026 at 12:55, Ilias Apalodimas
>>>>> <ilias.apalodimas at linaro.org> wrote:
>>>>>>
>>>>>> Hi Michal
>>>>>>
>>>>>> On Tue, 10 Mar 2026 at 15:50, Michal Simek <michal.simek at amd.com> wrote:
>>>>>>>
>>>>>>> Commit 4cb724364030 ("efi_loader: Disable ANSI output for tests")
>>>>>>> introduced efi_console_set_ansi() to suppress ANSI escape sequences
>>>>>>> during unit tests. Extend this mechanism to be runtime-configurable via
>>>>>>> the 'no_ansi' U-Boot environment variable.
>>>>>>>
>>>>>>> When 'no_ansi' is set to 'yes', efi_console_set_ansi(false) is called
>>>>>>> at the start of efi_setup_console_size(). This prevents
>>>>>>> query_console_serial() from sending ANSI escape sequences to the
>>>>>>> terminal, using default 25x80 dimensions instead. This is useful for
>>>>>>> platforms where the serial console cannot handle ANSI queries.
>>>>>>
>>>>>> I am fine with the patch, but the no_ansi is a bit misleading reading the code.
>>>>>> It really means don't use ANSI queries to detect the console.  So
>>>>>> before creating an ABI to the cmd line should we really call it
>>>>>> "no_ansi" or perhaps "no_detect" and in the future clean up the
>>>>>> variable names as well?
>>>>>
>>>>> I wonder whether this should be a Kconfig option too, a maker of a
>>>>> device likely knows when this is an issue on their device and
>>>>> explicitly enabling it via a config as opposed to an environment
>>>>> variable would likely be useful when there's a menu enabled and the
>>>>> shell possibly disabled?
>>>>
>>>> There are a lot of Kconfig options and variable which can aligned it.
>>>> It means we can create Kconfig option for it but likely we should also have
>>>> variable way as common way in uboot.
>>>>
>>>
>>> Reviewed-by: Simon Glass <sjg at chromium.org>
>>>
>>> It might also be worth reconsidering this old patch:
>>>
>>> https://patchwork.ozlabs.org/project/uboot/patch/20231121113557.800353-5-sjg@chromium.org/
>>> https://patchwork.ozlabs.org/project/uboot/patch/20240815202424.766778-11-sjg@chromium.org/
>>> https://patchwork.ozlabs.org/project/uboot/patch/20240902011825.746421-11-sjg@chromium.org/
>>
>> We have met with this problem on real HW last year and based on it we created
>> this internal patch.
>> https://github.com/Xilinx/u-boot-xlnx/commit/29b1330570543056188e5c065f1ea1be064b3a4b
>>
>> And we also send it out
>> https://lore.kernel.org/all/SJ0PR12MB66857BFB90475FE74294CF0482C22@SJ0PR12MB6685.namprd12.prod.outlook.com/
>>
>> That's why I would like to get clear guidance which way you want to go and how
>> things should be changed. If you are fine with having variable/Kconfig symbol to
>> disable it, then I am happy to create a patch for it.
> 
> Ok thinking about it again I think Peter has a point. Having a runtime
> option would make sense if the feature would work at some point. Is
> there a case that you would want to enable ANSI sequences? Otherwise
> we can just turn this into a Kconfig.

I just want to have a way to disable it. I don't have a need to change it at run 
time.

Thanks,
Michal