Red Hat Bugzilla – Bug 468100
"plymouth --hide-splash" clears screen when booting without "rhgb quiet"
Last modified: 2009-10-05 11:01:48 EDT
If I boot 220.127.116.11-30.rc1 without "rhgb quiet", just before this message appears:
Session finished...exiting logger
...something clears the screen and moves the cursor to (0,0).
2.6.27-13.0 doesn't do this; the "Session finished...exiting logger" line just scrolls the display. (The initird init scripts are the same for both kernels, so there must be something in 18.104.22.168-30.rc1 that is clearing the screen.)
Scrolling the display is preferable to blanking the screen, as blanking the screen erases boot messages that may have value (see bug 461797).
The kernel shouldn't be doing anything here. This is either initscripts, or possibly plymouth.
After much "debugging via printk()" (so to speak), I've isolated what is clearing the screen, which is:
(rc.sysinit's init_crypto() function runs "plymouth --hide-splash" before it runs cryptsetup.)
The bizarre thing is that plymouth only has this behavior with 22.214.171.124-30.rc1. With 2.6.27-13.0, the screen isn't cleared. This is 100% reproducible (by alternating booting with one kernel and then the other).
My guess is that plymouth's --hide-splash option has been trying (and failing) to clear the screen all along, but changes between 2.6.27-13.0 and 126.96.36.199-30.rc1 have "fixed" it so that plymouth actually succeeds now.
Re-filing against plymouth...
okay, so what's going on is,
hide_splash_screen() for the details plugin has:
uninitialize_window, NULL, NULL);
We do this so that when plymouth quits the screen is blank so the crossfade to gdm fades from black instead of boot messages.
Sort of hard to fix that case and this one. I guess crossfading from boot messages when you are using details isn't that bad, so I'll do that (especially since showing boot messages isn't the default)
This should be fixed in the latest builds.
(I'm still seeing this for plymouth-0.6.0-0.2008.11.10.5, which is the latest in rawhide ATM, but I'm not sure if there's anything else in the build queue...)
Make sure you rebuild your initrd (with /usr/libexec/plymouth/plymouth-update-initrd or /sbin/mkinitrd -f /boot/initrd-$(uname -r).img $(uname -r) or installing a new kernel) after updating plymouth.
I think the build you mentioned should have the fix in it, but there have been several builds since then.
This bug appears to have been reported against 'rawhide' during the Fedora 10 development cycle.
Changing version to '10'.
More information and reason for this action is here:
Everything has been working properly in F10 current; booting with "nomodeset" and without "rhgb quiet" loses no console output.
Is it really necessary to specify "nomodeset" without "rhgb" in order to see the boot messages? This seems more trouble than should be needed. It certainly made me have to poke around and find this bug report.
No, shouldn't be neccessary. If it's broken again, please file a new bug.