Bug 18943

Summary:	installer confused by UEFI firmware, mbr partitioned drive and CSM flag.
Product:	Mageia	Reporter:	Peter D <0123peter>
Component:	Installer	Assignee:	Mageia Bug Squad <bugsquad>
Status:	RESOLVED INVALID	QA Contact:
Severity:	normal
Priority:	Normal	CC:	marja11, thierry.vignaud
Version:	Cauldron	Keywords:	NEEDINFO
Target Milestone:	---
Hardware:	All
OS:	Linux
Whiteboard:
Source RPM:		CVE:
Status comment:
Attachments:	requested file

Description Peter D 2016-07-14 15:32:06 CEST

Description of problem:

When attempting to install on an UEFI computer, an ASROCK 970 Pro3 R2.0, with the CSM flag set and an mbr partitioned hard drive things got messy.  

The motherboard is a bit suspect, but not in a way that would cause these problems.  

Ausrock help says, "please don't change the CSM flag", so I didn't.  It has previously booted from an EFI partition on a GPT disk, while the CSM flag was set.  I swapped an old drive in for testing.  

The CSM flag might be what is confusing the installer here.  

After selecting the custom option, the installer did not offer to repartition the drive with GPT, only reformat.  It insisted on a BIOS boot partition, which is not needed with this firmware.  It did not offer to create an EFI partition, like I wanted.  I did create a small Windows partition without a mount point, but that was not enough.  I foolishly selected LiLo as the boot loader to be installed to /dev/sda.  (Hey, I like LiLo.)  It failed.  

It seems to have written to the nvram with efibootmgr or similar, because it now will not boot from the hard drive (no surprise there) or from the DVD, that was a surprise.  I will open the case and do a factory reset later.  

Version-Release number of selected component (if applicable):

Mageia 6 sta1, classic installer on DVD.  

How reproducible:

Only tried once.  

Steps to Reproduce:
1.  DVD in drive 
2.  follow the promts
3.

Comment 1 Thierry Vignaud 2016-07-14 23:03:00 CEST

A BIOS boot partition (!= EFI partition) is indeed needed for grub2 on a GPT disk.
See https://en.wikipedia.org/wiki/BIOS_boot_partition for the gory partition.

An EFI partition won't be offered as it's nonsence in CSM mode (aka !UEFI mode).

Please attach your /root/drakx/report.bug.xz

Keywords: (none) => NEEDINFO
CC: (none) => thierry.vignaud

Comment 2 Peter D 2016-07-22 15:04:37 CEST

Are you assuming that everyone in the computer industry is sane?  I promise you that much nonsense is spoken, written, coded, and believed.  

There exists at least one motherboard where the Compatibility Support Module (not Mode) definitely allows booting of UEFI installations, as well Master Boot Records, all are offered in the firmware's boot menu.  Let's be generous and assume that Asrock meant, "compatible with non-Windows OSes".  Their firmware does state, and this time I quote, "This option controls if Compatibility Support Module will be launched. Please don't set to disable unless running WHCK test."  It looks like Windows Hardware Certification Kit ONLY to me, not even to run Windows.  It has happily run UEFI Linux installations for years with the "compatible" flag set, including Mageia 5 and Mageia 4 (with a bit of stuffing around).  

Roderick Smith, the author of rEFInd, has written some good documentation about booting.  REFInd is an UEFI program that will look for bootable things (EFI and BIOS) then offer them in a menu.  

A very long time ago I read the documentation about LiLo and am rather biased towards LiLo on BIOS machines, and rEFInd on UEFI machines.  YMMV

Comment 3 Peter D 2016-07-22 15:07:12 CEST

Created attachment 8224 [details]
requested file

Comment 4 Peter D 2016-07-24 12:43:58 CEST

My apologies, the installer is actually controlled by how you boot the installation DVD.  If started as an UEFI disc it creates an EFI partition, if started as a traditional disc (BIOS?  El Torito?) it creates a BIOS boot partition.  

After another couple of installs to the test machine it has an UEFI Mythbuntu, an UEFI Mageia, and a BIOS Mageia, all on the same hard drive - including an EFI partition and a BIOS boot partition.  All are bootable.  

The Ubuntu installer offers to re*partition* the hard drive as well as reformat, the Mageia installer does not.  I think that it should.  

Of course changing partition table types without destroying data is a complex process.  A prominent warning would be in order.  

So, new bug report or change the title of this one?  Downgrade to a feature request?

Comment 5 Thierry Vignaud 2016-07-24 19:19:44 CEST

Let's close this one as invalid

Status: NEW => RESOLVED
Resolution: (none) => FIXED

Comment 6 Marja Van Waes 2016-07-24 22:21:46 CEST

@ Peter

Please don't reopen this report for that enhancement request.

You're free to file a new report for it, of course :-)

If you really want diskdrake to be able to switch the partition table of a disk from dos to gpt and back, without destroying data, then please attach your patches to that enhancement request.

The diskdrake code (for installer and for MCC, there are some differences) is part of drakx here
http://gitweb.mageia.org/software/drakx/

CC: (none) => marja11
Resolution: FIXED => INVALID