Halting auto-boot process in the U-Boot shell https://lore.kernel.org/u-boot/20220614060203.33600-1-heinrich.schuchardt at canonical.com/

[Michal Simek]

On 2/26/25 09:23, Heinrich Schuchardt wrote:
> On 2/26/25 07:48, Kummari, Prasad wrote:
>> [AMD Official Use Only - AMD Internal Distribution Only]
>>
>>
>> Hi Heinrich,
>>
>> Regarding below commit.
>>
>> commit 68edbed454b863dbcd197e19e1ab26a0a05c7d85
>> Author:     Heinrich Schuchardt <xypron.glpk at gmx.de>
>> AuthorDate: Tue Jun 14 08:02:03 2022 +0200
>> Commit:     Heinrich Schuchardt <xypron.glpk at gmx.de>
>> CommitDate: Sun Jun 19 15:53:09 2022 +0200
>>
>>      efi_loader: initialize console size late
>>
>>      If CONFIG_VIDEO_DM=n we query the display size from the serial console.
>>      Especially when using a remote console the response can be so late that
>>      it interferes with autoboot.
>>
>> *    Only query the console size when running an EFI binary.*
>>
>> https://lore.kernel.org/u-boot/20220614060203.33600-1- 
>> heinrich.schuchardt at canonical.com/ <https://lore.kernel.org/u- 
>> boot/20220614060203.33600-1-heinrich.schuchardt at canonical.com/>
>>
>> Commit 68edbed454b863dbcd197e19e1ab26a0a05c7d85 modifies the system to query 
>> the console size only when running an EFI binary. However, when 
>> CONFIG_EFI_CAPSULE_ON_DISK is enabled, the console is still being invoked, 
>> which shouldn't happen. This results in issues on our terminal, which cannot 
>> handle the resulting characters, leading to incorrect display and halting the 
>> auto-boot process in the U-Boot shell.
>>
>> *Log Output:*
>>
>> Warning: ethernet at ff0c0000 (eth0) using random MAC address - ee:df:0a:38:a8:c4
>>
>> eth0: ethernet at ff0c0000, eth1: mrmac at a40f0000, eth2: mrmac at a40f1000, eth3: 
>> mrmac at a40f2000, eth4: mrmac at a40f3000
>>
>> Cannot persist EFI variables without system partition
>>
>> Missing TPMv2 device for EFI_TCG_PROTOCOL
>>
>> Missing RNG device for EFI_RNG_PROTOCOL
>>
>> Hit any key to stop autoboot:  0
>>
>> *Versal> [42;173R*
>>
>> *Unknown command '[42' - try 'help'*
> 
> Hello Prasad,
> 
> The terminal emulation seems to be sending a valid reply indicating 42 rows and 
> 173 columns.
> 
> It could be that in your setup you are hitting the time out in term_get_char().
> 
> Could you, please, check what happens if you apply
> 
> --- a/lib/efi_loader/efi_console.c
> +++ b/lib/efi_loader/efi_console.c
> @@ -92,8 +92,7 @@ static int term_get_char(s32 *c)
>          timeout = timer_get_us() + 100000;
> 
>          while (!tstc())
> -               if (timer_get_us() > timeout)
> -                       return 1;
> +               ;
> 
>          *c = getchar();
>          return 0;
> 
> If the failure disappears, next you would have to analyze why the timeout is 
> occurring (e.g. timer_get_us() running too fast).
> 
> If you still get failures, please, add debug output term_read_reply() to 
> understand what is happening.

But why is this send at this stage? Why capsule update needs to be aware about 
size of terminal? I understand that you need to know it for efi application but 
what's the reason to know it capsule update?

Thanks,
Michal