Re: Grub2 UEFI boot and serial console output

[Andrei Borzenkov]

On Mon, Jan 16, 2017 at 12:25 PM, Matwey V. Kornilov
<address@hidden> wrote:
> 2017-01-16 12:22 GMT+03:00 Andrei Borzenkov <address@hidden>:
>> On Mon, Jan 16, 2017 at 11:36 AM, Matwey V. Kornilov
>> <address@hidden> wrote:
>>>>
>>>> I think here is my issue:
>>>>
>>>> terminal_input says that 'console' is active terminal and no other
>>>> terminals available.
>>>>
>>>> serial --speed=115200 efi0 says "can't find command `serial'"
>>>>
>>>
>>> Ok, now I see! There is file /boot/grub2/x86_64-efi/serial.mod but
>>> isnmod serial says that there is no such file.
>>>
>>
>> Well
>>
>> 1. $prefix must be set correctly (normally is done for you by
>> grub-install & Co.; I do not know how you created your image)
>> 2. Device which is part of $prefix must of course exist. You may need
>> to explicitly load partition driver (not autoloaded) and/or virtual
>> storage drivers (Linux MD, LVM2, LUKS, etc)
>> 3. You need filesystem driver for this device (normally autoloaded).
>> 4. Most vendors build images for use with Secure Boot that disable
>> module load. Unless module is included in the image by vendor, it is
>> flat unavailable. If you are using such image (you most likely do if
>> you enabled secure boot support in your OS configuration) - check how
>> image is built. You are using openSUSE, are not you?
>>
>
> Thank you. Yes, I am using openSUSE. And there is Secure Boot... All
> this has been made by default installer.
>

OK, I suggest that for testing you disable Secure Boot both in
firmware setup and in YaST2. Then you will be using standard image
generated by grub-install and will have access to all grub modules
under $prefix. When you are sure serial port works for your setup,
just submit SR to add serial to list of modules in signed grub image
(see grub2.spec).