Is it possible to pass parameters to kernel at boot screen with opensuse 12.2 + GRUB2? (One-time only.)
We used to pass often “3” and “acpi=off” for debugging.
Now, how do I boot an installed 12.2 system to no-graphics mode?
Are we going direction Ubuntu: “Why do you want to boot text-only?” "Why do you even need to know that a nongraphical boot exists? " “What is “3”?”
Sure. Just like with Grub1 press ‘e’ to edit selected boot entry, add (or remove) options in “linux …” line and boot with Ctrl-X (or F10)
On 09/17/2012 09:06 AM, arvidjaar wrote:
>
> Sure. Just like with Grub1 press ‘e’ to edit selected boot entry, add
> (or remove) options in “linux …” line and boot with Ctrl-X (or F10)
hmmmmm…i read that and wondered how i had missed learning that for all
these years…so, using grub1 (openSUSE 11.4 with KDE4.6) i shut down to
reboot and give it a try…when the first green screen popped up (as
always), with the desktop entry i wanted to boot to selected, i typed
‘e’ and it appeared in the screens Boot Option line, as i expected…
but then nothing happened… nothing at all…i wasn’t offered a line of
options to edit in a “linux …” line
nothing, so i figured i need to press enter, i did and the boot
progressed to the KDE desktop…
so, that is not the way it works on my grub1 launched openSUSE.
and, anyway if i wanna go to a command line (as the OP asked) i just
type ‘3’ (not ‘e’) and press enter…but, i do not think that works
with systemD, and i do not know what does (and neither does the asking
originator of this thread)
i’d love to hear if ‘e’ works on 12.2, or not !!
–
dd http://goo.gl/PUjnL
Grub1 splash screen is add-on; you need to quit splash screen with ESC to return to native Grub Legacy (text mode only) interface to be able to edit menu entry.
GRUB2 supports graphic mode natively, so it is not required.
if i wanna go to a command line (as the OP asked) i just type ‘3’ (not ‘e’) and press enter
You are of course right. For Grub1 with its splash screen. But when I often also need to remove kernel parameters and this is not possible in splash. So it is easier to always do it consistently
On 09/17/2012 10:16 AM, arvidjaar wrote:
>
> GRUB2 supports graphic mode natively, so it is not required.
so it is not, as you wrote “Just like with Grub1 press ‘e’ to edit” ??
that is, you must first press “Esc” (prior to the first green screen,
right after the BIOS flash) or what?
–
dd
On 2012-09-17 09:50, dd@home.dk wrote:
> but then nothing happened… nothing at all…i wasn’t offered a line of options to edit in a
> “linux …” line
You are mixing grub 1 with grub 2 instructions. 
> and, anyway if i wanna go to a command line (as the OP asked) i just type ‘3’ (not ‘e’) and
> press enter…but, i do not think that works with systemD, and i do not know what does (and
> neither does the asking originator of this thread)
A 3 on the kernel command line of 12.1 works with systemd.
–
Cheers / Saludos,
Carlos E. R.
(from 12.1 x86_64 “Asparagus” at Telcontar)
On 09/17/2012 12:33 PM, Carlos E. R. wrote:
> You are mixing grub 1 with grub 2 instructions.
i think arvidjaar (not me) is doing just that…
i think s/he is giving grub instructions to an OP who specified “Is it
possible to pass parameters to kernel at boot screen…?” (which is
not the same as “at grub[1 or 2] command line”
and, still i don’t know if a user can type “3” or “acpi=off” into the
boot screen’s Boot Options line and get in 12.2 what you could get since
about SUSE 9.x, or not…
but, since that is exactly the question, i assume a user cannot…and,
i really doubt if typing “e” works either…but, that remains to be
seen in the report of ZStefan or anyone else brave enough to install 12.2 !
–
dd
On 2012-09-17 14:38, dd@home.dk wrote:
> On 09/17/2012 12:33 PM, Carlos E. R. wrote:
>> You are mixing grub 1 with grub 2 instructions.
>
> i think arvidjaar (not me) is doing just that…
>
> i think s/he is giving grub instructions to an OP who specified “Is it possible to pass
> parameters to kernel at boot screen…?” (which is not the same as “at grub[1 or 2] command
> line”
The OP is using grub2, he said so.
> and, still i don’t know if a user can type “3” or “acpi=off” into the boot screen’s Boot
> Options line and get in 12.2 what you could get since about SUSE 9.x, or not…
Not directly, no. You have to enter edit mode first.
–
Cheers / Saludos,
Carlos E. R.
(from 12.1 x86_64 “Asparagus” at Telcontar)
You can press ‘e’ to edit a command before booting, then Ctrl-X or F10 to boot, just like @arvidjaar explained. However you don’t see the kernel command line in this Grub editor but the whole boot entry (which could be about ten lines long). You have to move to the kernel line, the one starting with “linux” to add or remove kernel boot parameters. From there, you can also pres F2 to open a Grub shell.
Actually @dd@home.dk is mixing Grub1 interface and Grub1 splash screen. 
I apologize for possible confusion, but for me these are completely separate. And I never said “press ‘e’ during splash screen”; I reviewed my posts and I still believe they are technically correct.
Once more, I apologize for possible confusion.
Thanks to all, ‘e’ worked. It is not guessable, though. I tried TAB, ESC and maybe a few others.
Would be good if there was a hint about ‘e’ on the boot screen.
On 09/20/2012 12:46 AM, ZStefan wrote:
> Thanks to all, ‘e’ worked.
does not work here and i can only guess that is because i’m using 11.4
–
dd
But the grub gfxterm is quite unreadable (text is light grey on light green). I actually happenend to have solved this problem before it even occured, as I installed Grub2 on 12.1 already and - among other things - set a readable font color for the Grub shell. updateGrub2 didn’t work on 12.2 BIOS systems until I applied some modifications, which I just did. I guess it’s fine now.
You can install updategrub from my repo and use the command “updategrub” whenever you need to update the menu. It will add the script 05_menu_color to /etc/grub.d (the first time as this file doesn’t exist) . This script will be executed every time the Grub menu is refreshed (whether manually by running updategrub or grub2-mkconfig … or automatically after a kernel update, for example.)
Here’s what 05_menu_color writes in /boot/grub2/grub.cfg:
### BEGIN /etc/grub.d/05_menu_color ###
set color_normal=black/black
set color_highlight=white/black
### END /etc/grub.d/05_menu_color ###
Here’s the script 05_menu_color:
#!/bin/sh -e
set -e
prefix=/usr
exec_prefix=/usr
. /usr/share/grub2/grub-mkconfig_lib
COLOR_NORMAL="black/black"
COLOR_HIGHLIGHT="white/black"
if "${GRUB_TERMINAL_OUTPUT}" = "gfxterm" ] ; then
cat <<EOF
set color_normal=${COLOR_NORMAL}
set color_highlight=${COLOR_HIGHLIGHT}
EOF
else
cat << EOF
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
EOF
fi
The location of grub-mkconfig_lib has changed. That’s what I had to fix to get updateGrub2 work on 12.2.
If you don’t want to use updategrub, you might copy/paste the code above, save as /etc/grub.d/05_menu_color and make the file executable. Then refresh the menu with:
# updategrub
if you trust me
or
# grub2-mkconfig -o /boot/grub2/grub.cfg
if you don’t (cause you don’t have to). Reboot, press “e” at the Grub screen to edit a menu entry and see the difference!. 
I have added the ability to create a script for grub 2 in my bash script Grub2Cmd using please_try_again’s example coding taken from right here which works like a champ. Please check it out if you have a chance.
GNU Grub2 Command Help/Config Editor - Version: 1.85 - Blogs - openSUSE Forums
Thank You,