Ubuntu Wiki

(UDS notes, pasted from the blueprint used to schedule the UDS session)

Let's make a note to talk about startup looks as well as resume/return from screensaver looks. In particular, if the login screen is too similar to the latter the user might enter their password as their username.

-- BoF notes --- Plymouth? Other cool stuff? https://blueprints.edge.launchpad.net/ubuntu/+spec/karmic-start-up-look-and-feel

• Goals:
  • Fast --- 10 seconds (ssd drives?)
  • flicker-free (need KMS)
  • switch X to VT1 in gdm/kdm/xdm (pitti/seb128), disable getty on tty1 in upstart (Keybuk)
  • preferably not support both usplash and plymouth (duplicates theming effort, etc.)
  • Ability to switch to another OS while booting---boot loader should not disrupt the boot process or fiddle with screen
  • Kernel team intends for Grub to be silent (and switch to grub 2)
• KMS impacts
  • Needs fallback for non-kms drivers (-nvidia, etc.)
• OS Switcher:
  • User could trigger it during boot process
  • While the user is selecting the session, the system is essentially ready to start, waiting for him to choose
  • Same type of screen could be called from the user session, ex: at logout or after selecting reboot
  • We don't want people to feel anxiety about switching back and forth
  • Preferable to put the switcher in the GDM/KDM/XDM menu?
  • gdm starts at 3s in the startup sequence, so the os-switcher could be implemented as a gdm plugin
  • What happens if bootup fails?
    • - Come back with grub providing a menu, so the user can select rescue mode.
      • - Have grub by default go to menu, but be constantly told to hide the menu whenever user reboots from Ubuntu
        • but make sure that rebooting into windows doesn't cause a subsequent reboot to always go windows (reset default when boot into other OS)
  • If forced to switch at GDM (only), would boot be fast enough so that users
    • don't find booting into Ubuntu, then rebooting into their desired OS? - If kernel or X breaks, user wouldn't be able to boot into another OS
  • on kernel panic: kexec into a working system and file a bug

    • - https://wiki.ubuntu.com/specs/KernelKarmicBugHandling

  • on OOPS or warnings: Better to have apport popup on successful login to report a bug?
  • Filesystem checks are what hold up the boot at the moment
  • fsck integration needs integration with plymouth if we use it
  • Have design on bootup become "more ubuntu" as bootup progresses
    • - Dark GDM theme was chosen because it resembled the rest of the boot splash
  • Trigger a shutdown, tell grub what to reboot into.
    • - What to print on screen at shutdown? If we leave the video driver loaded, we
      • could leave a message box saying shutting down. At the moment, we only clear the screen. + We need to provide some form of feedback to the user to let him/her know what we're doing. + In text mode, shutting down provides a wall message, shutting down now, etc. + Probably easier just to fade to black at the end, the time between telling
        • the user what we're doing, fading to black and rebooting will be incredibly short anyway.
        + Can also show a message using an arbitrary graphical application (when in kernel mode) that then fades to black, eg: rebooting into Windows or rebooting into old kernel
  flicker mitigation strategy for non-KMS compatible drivers: use text mode, and wait for X to drive the screen; and using a black / empty screen (just before flicker is planned). We need a text mode boot anyway for ubuntu server.
• only ever touch the mode once by the kernel or X.org graphics driver
• only two modes for fsck/encryption passphrase: text for server and non-KMS, and "pretty" for KMS
  • - two supported systems at the moment: ecryptfs (private directory),
    • dm-crypt (whole filesystem)

• Wouldn't need usplash if boot is under 5s -> let's drop usplash altogether, to remain with two cases (text/plymouth)

• -poulsbo is KMS-enabled already
• -openchrome
• hibernate:
  • - this is why having i915 built into kernel would be benefical
    • - Would this require having an Intel graphics card?
• The prettier you make resume, the longer it'll take. Text mode will make it quicker
  • - Would be a black screen, with only a white bar moving across the screen.

In-kernel throbber: no interest, because it requires a graphic infrastructure (drivers) that is not available early enough

Let's not forget about Kubuntu (KDM) and the variants using XDM.