booting trouble

[Adys]

this recent change that requires using the memdisk for cdrom booting and the memdisk was initially not explicitly designed for that use by me. Maybe JRD can shed some more light onto this.

If MEMDISK is part of the problem, then maybe for newer ISOLINUX versions the syslinux/isolinux.cfg should be changed from:

Code: Select all

DEFAULT grub2
PROMPT 0
NOESCAPE 1
TOTALTIMEOUT 1
ONTIMEOUT grub2
LABEL grub2
  SAY Chainloading to grub2...
  LINUX /boot/g2l.img

into:

Code: Select all

DEFAULT grub2
PROMPT 0
NOESCAPE 1
TOTALTIMEOUT 1
ONTIMEOUT grub2
LABEL grub2
  SAY Chainloading to grub2...
  LINUX MEMDISK
  INITRD /boot/g2l.img

[EDIT]
I noticed I made a mistake in my suggested code. I originally wrote:

Code: Select all

LINUX MEMDISK
APPEND /boot/g2l.img

but it should be

Code: Select all

  LINUX MEMDISK
  INITRD /boot/g2l.img

with some possible additional APPEND code if necessary.

I have corrected my suggestion now. My apologies for any inconvenience.
[/EDIT]

[mimosa]

It is still strange that it is failing in the same way for you in 3 different computers, while it works correctly for other users.

You can say that again

[JRD]

I was not involved in this recent change that requires using the memdisk for cdrom booting and the memdisk was initially not explicitly designed for that use by me. Maybe JRD can shed some more light onto this.

Well in fact, I use the same grub2 modules for booting from USB or from CD. Then iso9660 is loading in both cases, so grub should find the CD (and the .live file then, …).
The only problem I can see is if the BIOS does not list the CD, so grub2 cannot find it.

mimosa, try Adys suggestion : boot with the CD without anything else connected (especially not the USB key). Report back any error message you got.
If you get a grub2 rescue shell (and I think you will), please type the following command and report back the result : ls

[Shador]

If you get a grub2 rescue shell (and I think you will), please type the following command and report back the result : ls

Actually ls is already implictly called when dropping to the rescue shell through the memdisk. They're listed with the comment "Available devices are:". Anyway either way a full listing of the devices outputed is fine.

Another thing you could try. Find the cdrom device on your system probably /dev/cdrom and run qemu -cdrom /dev/cdrom (or whatever the right device is). I.e. boot your Salix Live CD virtually through qemu. Obviously the physical cdrom you created should be in your cdrom drive. If it boots that way, then it's definitely related to your BIOS and could be a bug of either grub or your BIOS implementation.

[Adys]

If you get a grub2 rescue shell (and I think you will), please type the following command and report back the result : ls

Actually ls is already implictly called when dropping to the rescue shell through the memdisk. They're listed with the comment "Available devices are:". Anyway either way a full listing of the devices outputed is fine.

I though the resulting messages are the ones mimosa already posted (which I repeated too). Maybe I am misunderstanding JRD's request . Or maybe he is specially interested in the "ls" result more than in the rest of the error messages.

Still, some info about the BIOS settings and more specific hardware information could be useful.

Another thing you could try. Find the cdrom device on your system probably /dev/cdrom and run qemu -cdrom /dev/cdrom (or whatever the right device is). I.e. boot your Salix Live CD virtually through qemu. Obviously the physical cdrom you created should be in your cdrom drive. If it boots that way, then it's definitely related to your BIOS and could be a bug of either grub or your BIOS implementation.

The BIOS is a key factor here, but then why 3 different computers are all failing for mimosa? Could it be just a coincidence regarding BIOS settings? But then why the older version of ISOLINUX in Salix Xfce is working in the same computers? Hence my suggestion of adding MEMDISK between ISOLINUX and GRUB.

@JRD, I corrected my previous suggestion regarding the use of ISOLINUX -> MEMDISK -> GRUB img (I previously made a mistake in the cfg code, sorry).

[mimosa]

@ JRD

The cd does boot with qemu. I'll try the experiment Adys proposed with the BIOS settings just in case.

As Adys pointed out, the output I posted from the cd already contains a list of available devices - basically just the hard disk. However, when I do the BIOS experiment, assuming the disk still fails, I'll try ls in case it provides anything extra.

[JRD]

Ok, so a BIOS problem. Could be that all three computer you use are about the same age and have the same exact problem.

Using memdisk com32 binary from syslinux in between isolinux and grub2 could be an option. I know that memdisk could deal with some weird thing in bios and can do realocation. Could also be the option than the cd is not available at all from the bios. isolinux is working fine because it uses block-mode access from the memory he's loaded (from the cd), without accessing directly the CD. After the Linux kernel has boot, then the CD is available again and so the boot can continue.

But do memdisk can boot linux kernel ? Because g2l.img is a kind of linux kernel (in the signature at least). It cannot boot grub2 core.img for sure.

[Edit] Maybe your BIOS is puzzled with isohybrid CD and then can boot into it, using el Torito + isolinux, but will not make it available further because of the presence of a MBR at the start of the CD.

[mimosa]

No luck changing BIOS settings.

EDIT @JRD No they are a new Thinkpad, a cheap desktop two or three years old, and a really ancient machine. The BIOS interface looks different for each.

The output of ls is the same as posted previously.

[JRD]

We can try to build another ISO using grub2 directly (as before) and using isohybrid with grub2 directly. I found this that can use grub2 in El Torito and make it a IsoHybrid image, instead of using an El Torito Isolinux image.

Shador, could you look at it? My german is poor and the translation (by google & co) is hard to understand.

[Adys]

We can try to build another ISO using grub2 directly (as before) and using isohybrid with grub2 directly.

@JRD,

The computers mentioned by mimosa seem to be different enough between each other, and yet in qemu the CD boots in those systems. So, instead of changing the current booting methods, maybe a simpler test by mimosa could help? Using CD-RW would allow testing without having to throw out CDs.

Anyway, my proposal would be to expand the current MATE ISO, delete "[BOOT]", replace isolinux.bin with the one from Syslinux v.3.84, re-build a new ISO, test it in qemu and if that works OK then burn it to a CD-RW. With this new burnt ISO, test all 3 systems again.

This new ISO should not use isohybrid, and should use the same old version of isolinux.bin that was used for SalixLive Xfce, and it would be very helpful to post the EXACT mkisofs command line with ALL the relevant parameters that should be used.

Of course the BIOS settings and specific hardware could still be related (which exact settings we still don't know), but if changing the isolinux version works, then we can narrow down the potential solutions to be related to either:

A_ isolinux regression bug; or
B_ isolinux retired feature; or
C_ isohybrid issue; or
D_ isolinux.cfg commands that may need small changes for wider compatibility.

Of course all this would depend on mimosa and JRD, and providing all the relevant info before and after the tests, so this is just a suggestion with little actual collaboration from my part .

My point is that whichever change is made for future ISO images, we still don't really know escential info and where the problem resides.

[EDIT]
@JRD,

Remember that the systems are booting correctly from USB, and "from CD" when the USB is connected, stopping at grub2 (after isolinux), so knowing more about the hardware and the BIOS settings is important, for whichever change you would like to try.

[/EDIT]