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Bug 851265 - booting a wrong arch results in a black screen
Summary: booting a wrong arch results in a black screen
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Fedora
Classification: Fedora
Component: grub2
Version: 18
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Peter Jones
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: AcceptedNTH RejectedBlocker
Depends On:
Blocks: F18-accepted, F18FinalFreezeExcept
TreeView+ depends on / blocked
 
Reported: 2012-08-23 15:28 UTC by Kamil Páral
Modified: 2012-12-06 11:14 UTC (History)
13 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2012-12-06 11:14:37 UTC
Type: Bug
Embargoed:

Attachments (Terms of Use)
wrong arch warning (101.56 KB, image/jpeg)
2012-08-23 15:28 UTC, Kamil Páral 		no flags Details
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Description Kamil Páral 2012-08-23 15:28:46 UTC 
Created attachment 606634 [details]
wrong arch warning

Description of problem:
By accident I have tried to boot a x86_64 DVD on a i686 machine. After confirming default syslinux option I only saw black screen. I tried several times and assumed this is a problem in Fedora or my graphics card. I also tried "safe graphics mode", nothing helped. Only my colleague saved my time by removing "rhgb quiet" from the boot line. After that I finally saw the warning (see warning.jpg).

So, the problem is that the warning is displayed only when "rhgb quiet" are manually removed from the boot line. In the default state only black screen is displayed. That really doesn't help to inform the user what the problem is.

What component is to blame? Something in syslinux, lorax, kernel itself?

Version-Release number of selected component (if applicable):
Fedora 18 Alpha TC3

How reproducible:
always on my hardware

Steps to Reproduce:
1. boot x86_64 image on i686 machine
2. see black screen instead of warning
Comment 1 Kamil Páral 2012-08-23 15:31:13 UTC 
In our release criteria we say:
" The installer must boot (if appropriate) and run on all primary architectures, with all system firmware types that are common on those architectures, from default live image, DVD, and boot.iso install media when written to a USB stick with any of the officially supported methods "

This is a corner case, where you try to boot unsupported architecture, so it doesn't directly fall into that criterion. But still I believe we should at least make sure the error message can be read. Proposing as final blocker.
Comment 2 Bill Nottingham 2012-08-23 17:15:10 UTC 
Actually, moving to kernel - perhaps the stub can disable quiet mode before printing the warning.
Comment 3 Dave Jones 2012-08-23 17:42:46 UTC 
that string gets printed out using bios int 10h calls. We don't even check for the quiet flag at that point.

My guess is that grub2 isn't setting the video mode ?
Comment 4 Mads Kiilerich 2012-08-23 19:17:59 UTC 
(In reply to comment #0)
> By accident I have tried to boot a x86_64 DVD on a i686 machine. After
> confirming default syslinux option I only saw black screen.

So if it isn't a kernel issue it must a syslinux issue? Or did you mean to say grub2?

(In reply to comment #3)
> that string gets printed out using bios int 10h calls. 

So if the boot loader starts the kernel while using 'boot loader mode setting' it is expected to have installed a new persistent int 10h handler that can print text messages while in the video mode? Interesting.

> We don't even check for the quiet flag at that point.

Then it is strange that the appearance of the message depends on the quiet flag. Or did it instead actually depend on different boot loader graphics modes?

> My guess is that grub2 isn't setting the video mode ?

In what way and at what level?
Comment 5 Kamil Páral 2012-08-24 08:25:32 UTC 
(In reply to comment #4)
> So if it isn't a kernel issue it must a syslinux issue? Or did you mean to
> say grub2?

Sorry, I don't really know the difference between those two. I always assumed that the boot menu used on CD/USB is syslinux, and the menu installed on the HDD is grub.

In this case, I'm just referring the the menu used on CD.

> Then it is strange that the appearance of the message depends on the quiet
> flag.

I have removed two flags - quiet and rhgb. Any of them could have caused it. I can test them separately, but not before Wednesday. Anyone with a i686 machine at hand can probably test it faster.
Comment 6 Reartes Guillermo 2012-11-27 16:53:00 UTC 
I also encountered it, when i tried to install to an atom netbook, i totally forgot about 32-bit existence... I eventually tried 'rhgb quiet' and i was able to see my obvious mistake. :-)

While it would be nice for the warning to be visible by default, i do not think this should block release. (A NTH maybe).
Comment 7 Adam Williamson 2012-12-05 17:20:46 UTC 
Discussed at 2012-12-05 blocker review meeting - http://meetbot.fedoraproject.org/fedora-bugzappers/2012-12-05/f18final-blocker-review-2.2012-12-05-17.01.log.txt . Agreed this is annoying but serious enough to block release. It is accepted as NTH if the fix is not too invasive.

(Between F16 and F17, grub2 starting doing modesetting; between F17 and F18, theming was added).
Comment 8 Kamil Páral 2012-12-05 18:04:00 UTC 
"but serious enough" -> "but not serious enough"
Adjusting whiteboard, I guess it was a mistake.
Comment 9 Kamil Páral 2012-12-06 11:14:37 UTC 
I have tested this with F18 Beta images and I see the error messages just fine now. Marking as fixed.
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