[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Bug#903641: Preserve numlock state during cryptdisk boot password prompt in plymouth



Control: tag -1 moreinfo

On Thu, 12 Jul 2018 15:02:20 +0200 Pascal Vibet - ADACIS <pvibet@gmail.com> wrote:
> Package: cryptsetup-initramfs
> Version: 2:2.0.2-1ubuntu1
> 
> Dear Maintainers, i propose you my fix to this problem.
> 
> I'm using smartcard to decrypt luks disk, i'm using decrypt_opensc 
> script in /etc/crypttab. I want to preserve numlock state during 
> cryptdisk boot password prompt.
> 
> I found this article: 
> https://superuser.com/questions/1062979/preserve-numlock-state-during-cryptdisk-boot-password-prompt-in-plymouth
[...]

If plymouth specifically changes Num Lock state, this may be a bug in
plymouth.  However, I don't think it does.

I have a theory as to what might be happening:

* Each Linux virtual terminal (VT) has an independent keyboard
  lock/LED state.  When a different VT is activated, the driver will
  apply the lock/LED state for that VT.
* If you boot Linux in BIOS mode, the default state of Num Lock is set
  acccording to what the BIOS says it should be.
* If you boot Linux some other way, like UEFI, the default state is
  unknown and assumed to be off.
* plymouth opens and activates a new VT.  This applies the default
 
state.

Does this system boot using the BIOS or UEFI?

If it boots using UEFI, you can test this theory by doing:

1. In the boot menu, edit the kernel command line to remove "splash"
   and add "break=premount".
2. At the initramfs shell prompt, enter "openvt" to create a new VT.
3. Press Alt-F2 to activate the new VT.  Does Num Lock turn off?
4. Press Alt-F1 to activate the first VT.  Does Num Lock turn on or
   off?

Ben.

-- 
Ben Hutchings
Power corrupts.  Absolute power is kind of neat. - John Lehman

Attachment: signature.asc
Description: This is a digitally signed message part


Reply to: