Need a way to pass the nomodeset kernel parameter during live CD boot

brainman69 · 2022-09-29 06:49:11

So, I have this old Dell Dimension with a Pentium III and 256MB of SDR memory, right, and I needed a Linux distro for GRUB, os-prober and some disk partitioning tools.

Obviously first distro I tested was the i486 build of Arch32 due to my familiarity with Arch Linux more generally. Problem arises when the live CD finishes booting, the kernel switches video mode, and video output breaks; can't see the actual frame buffer, just some text it printed earlier during the boot process. It isn't crashing, though, listing a directory causes the CD-ROM drive to show life. I just can't see what I'm typing or what's being printed to the console, which is a problem if I happen to run into errors getting the network or SSH setup and I can't see what the errors are.

The only reason I know this is because of kernel mode switching specifically is because I ran the live CD in VirtualBox and noticed that it switched video modes at around the same point in the process that the video output craps itself on the Dell-- so I think the underlying issue is something with the GeForce 2 Ti. Something about its VGA hardware isn't working right, or at least isn't documented well enough for most developers to avoid/work around its errata.

I also tried extracting and reassembling the .iso with mkisofs, iterating on the ISOLINUX configuration to try and get something working, to only moderate success. The kernel panics on trying to load systemd, I guess because of some kind of file name truncation/mangling during iso assembly which I'm not experienced enough with mkisofs to prevent. The syslinux wiki doesn't seem helpful enough in this regard, and I'm not sure where to go to find the necessary documentation (or maybe I overlooked something).

For right now though I got Gentoo installed and ready with appropriate kernel parameters and tools so I can proceed with what I actually want to do with this project (and I guess debug the friggin video card too), but I'd really like to use Arch instead, at least for now, as the idea of a full production environment on such a dinosaur is very enticing.

Any assistance that can be offered is much appreciated.

Last edited by brainman69 (2022-09-29 06:49:58)

abaumann · 2022-09-29 08:06:34

If you press [TAB], don't you get a command line where you can append 'nomodeset'
or 'i915.modeset=1' to the kernel parameters?

brainman69 · 2022-09-29 08:21:04

abaumann wrote:

If you press [TAB], don't you get a command line where you can append 'nomodeset'
or 'i915.modeset=1' to the kernel parameters?

I tried that, virtualized and I think on the actual machine itself. It didn't seem to do anything-- my input is just ignored and it continues booting with default parameters anyway. I'll dig up my CD and test it again just to be sure though.

Last edited by brainman69 (2022-09-29 08:23:16)

abaumann · 2022-09-29 08:23:00

Are you using the i686 ISO or the i486 ISO, the i486 one should always remain in text mode..

levi · 2022-09-29 08:23:06

Yes, the boot isos use syslinux to boot at least the ones I'm familiar with. There is a keystroke to edit kernel parameters there, though I couldn't remember what it was before I read your post. I take it that it is tab you need to press, as you say.

brainman69 · 2022-09-29 08:27:01

abaumann wrote:

Are you using the i686 ISO or the i486 ISO, the i486 one should always remain in text mode..

i486, obviously. I've only ever used that build AFAIK since other posts on the forums suggested that the i686 build used too much memory so I used the i486 one so the kernel doesn't crash on me.

levi wrote:

Yes, the boot isos use syslinux to boot at least the ones I'm familiar with. There is a keystroke to edit kernel parameters there, though I couldn't remember what it was before I read your post. I take it that it is tab you need to press, as you say.

Like I said, I tried that. I'm about to try it again though, so we will see.

abaumann · 2022-09-29 08:31:06

Ah, right, sorry about missing out your statement about 256MB of RAM, so you must use the i486 ISO.

Besides, the i486 ISO is a little bit dated, just trying myself now and of course mirrorlists and pacman keys are completely
outdated on the i486 ISO. Trouble is, the i486 is only semi-automatic at the moment, it's built with the scripts in
https://git.archlinux32.org/archi486/tree/iso.

I'll try myself to build it and see what I get.

I'm absolutely happy about the fact that another person uses the i486 version, just be prepared that it might be a little
bit bumpy to begin with. :-)

Another option is always to use the "set Architecture=i486, pacstrap on another machine" trick and then stick the
installed harddisk/CF into the Dell..

brainman69 · 2022-09-29 08:49:43

Welp, [tab] doesn't do anything. Even spamming it from the instant I powered on.

I got my copy of the i486 .iso from mirror.clarkson.edu/archlinux32/archiso … 6-i486.iso, might be important to know that for more fine-grained debugging.

abaumann wrote:

Trouble is, the i486 is only semi-automatic at the moment, it's built with the scripts in https://git.archlinux32.org/archi486/tree/iso.

Just what I'm looking for. Time for script analysis!

abaumann wrote:

I'm absolutely happy about the fact that another person uses the i486 version, just be prepared that it might be a little
bit bumpy to begin with. :-)

Not a problem for me, and if I knew all of what was required to actually get involved, I'd occasionally contribute to it. Better to fix it yourself and share it around to get it done faster, y'know?

abaumann wrote:

Another option is always to use the "set Architecture=i486, pacstrap on another machine" trick and then stick the
installed harddisk/CF into the Dell..

Ah, about that. The only other PC I have on hand with an IDE bus is doing mission-critical work at the moment. As in a three-month long dd. I have also considered using my working Gentoo install to bootstrap Arch... but that's redundant and a waste of space which could be going to the other operating systems. (I'm really quite particular about how my partition table is laid out, if you can't tell.) I was going to mention it in my original post but I decided to drop it because it would make it really long.

Last edited by brainman69 (2022-09-29 08:51:08)

abaumann · 2022-09-29 09:08:08

Uh, I think, I found the problem: https://git.archlinux32.org/archi486/tr … x-i486.cfg could really have a TIMEOUT, default seems to be 0.
So, you have absolutely no chance to press anything with timeout 0.. :-)

abaumann · 2022-09-29 09:19:30

Arg, I also moved things from the main directory to 'iso', so now things break.. (BASE=/root/archi486/iso).

brainman69 · 2022-09-29 10:13:45

abaumann wrote:

Uh, I think, I found the problem: https://git.archlinux32.org/archi486/tr … x-i486.cfg could really have a TIMEOUT, default seems to be 0.
So, you have absolutely no chance to press anything with timeout 0.. :-)

I tried implementing your changes independently after I found the extra options to get LFNs working. Kernel still complains about /sbin/init not existing and when specifying systemd in the kernel parameters it still panics. I'll take that as a sign that the other scripts are necessary to get a working archiso.

Last edited by brainman69 (2022-09-29 10:29:12)

abaumann · 2022-09-29 10:40:52

Yep, you need the whole iso directory.
(TIMEOUT takes tens-of-secods, I just wondered why TIMEOUT 5 was so fast..)

abaumann · 2022-09-29 11:20:38

So, it builds. I uploaded the ISO to: https://mirror.archlinux32.org/archisos … 9-i486.iso
Now in the boot prompt you can type and complete 'arch32' and then append any command line options.
I see them after booting in /proc/cmdline.

Keep in mind, that a lot of packages don't really build currently for i486.. don't expect a Gnome desktop to work.. :-)

brainman69 · 2022-09-29 13:34:21

Alright, sweet. And work it does indeed.

I gotta nitpick though: its slightly too large to be burned onto an actual 737MiB CD-R (the .iso is 744)-- not really an issue for me since I have GRUB installed, and apparently you can boot .iso images directly from it. Just something to think about.

abaumann · 2022-09-29 14:08:32

Oh, good point. I wonder, why it is so "fat" again. :-)

abaumann · 2022-09-29 14:51:35

-rw-r--r-- 2 mirror mirror 679M Sep 1 09:46 archlinux32-2022.09.01-i686.iso
-rw-r--r-- 1 http mirror 745M Sep 29 12:16 archlinux32-2022.09.29-i486.iso
-rw-r--r-- 1 http mirror 678M Sep 29 12:17 archlinux32-2022.07.01-i686.iso

This is strange, as even the default one is smaller..

abaumann · 2022-09-29 15:04:22

Unfortunately the i486 ISO is not compressed in any way, so base and some essential tools (dhclient) just got that big, it seems..
a ramdisk is out of question, as if you are low on memory, the last thing you probably want is a thing clogging up your memory.

I made some experiments with the i486 floppies to install from a busybox-based ramdisk (having just enough in order to
mount a 486 ISO you copy onto the local disk, chroot into it and then install from there). This of course assumes your 486-type
system is one with tons of free disk space. :-)

abaumann · 2022-10-02 09:40:21

The debate is open on https://mirror.archlinux32.org/irc-logs … l#10:31:29 about how to get the size of the 486 ISO down. :-)

abaumann · 2022-10-02 12:28:11

-rw-r--r-- 1 http root 627937280 Oct 2 13:25 archlinux32-2022.10.02-i486.iso

better :-)

Arch Linux

#1 2022-09-29 06:49:11

Need a way to pass the nomodeset kernel parameter during live CD boot

#2 2022-09-29 08:06:34

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#3 2022-09-29 08:21:04

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#4 2022-09-29 08:23:00

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#5 2022-09-29 08:23:06

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#6 2022-09-29 08:27:01

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#7 2022-09-29 08:31:06

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#8 2022-09-29 08:49:43

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#9 2022-09-29 09:08:08

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#10 2022-09-29 09:19:30

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#11 2022-09-29 10:13:45

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#12 2022-09-29 10:40:52

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#13 2022-09-29 11:20:38

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#14 2022-09-29 13:34:21

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#15 2022-09-29 14:08:32

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#16 2022-09-29 14:51:35

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#17 2022-09-29 15:04:22

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#18 2022-10-02 09:40:21

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

#19 2022-10-02 12:28:11

Re: Need a way to pass the nomodeset kernel parameter during live CD boot

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