gcc-4.9.1 makes buggy grub (waiting for confimation)

[ruslan]

When building grub-2.00 with its default CFLAGS I got buggy grub.

During setup(hd0) it was always "Error 6: Mismatched or corrupt version of stage1/stage 2"

Then I rebuilt grub with CFLAGS="-O1" and error dissapeared, setup(hd0) was successful.

I tested it on x86 laptop and in virtualbox in both cases it was the same behavior.

Looks that some optimization in gcc does not work well with grub.

[ruslan]

When building grub-2.00 with its default CFLAGS I got buggy grub.

During setup(hd0) it was always "Error 6: Mismatched or corrupt version of stage1/stage 2"

Then I rebuilt grub with CFLAGS="-O1" and error dissapeared, setup(hd0) was successful.

I tested it on x86 laptop and in virtualbox - in both cases it was the same behavior.

Looks that some optimization in gcc does not work well with grub.

[ken@…]

I cannot confirm this. My i686 7.6 system has a shared /boot, and I do not recall when I last reinstalled grub before today. So, after backing up, I rebuilt grub, noting that its default CFLAGS are -Os. Installed it, which updated all of /boot/grub/i386-pc/*, reboted. No problem. I then reran grub-install sda and again rebooted. Still no problem.

For anybody else testing this, on a desktop add --disable-grub-mkfont (it looks for an old header, I think from freetype).

What I am not sure of is where that setup(hd0) message is shown - is it during grub-install, or during the boot ?

[bdubbs@…]

Have you reported this to the grub maintainers? There is a grub-2.02 beta that's been out for several months. You might want to ask the maintainers about this issue at: ​https://lists.gnu.org/mailman/listinfo/grub-devel

Looking at the grub source. I could find no reference to the error message you report. I also could not find any reference to a command "setup", although there is a binary grub-bios-setup.

[ /sources/grub-2.00 ]$ grep -r -i mismatched *
build-aux/texinfo.tex:  % as its first line, TeX doesn't complain about mismatched braces
docs/texinfo.tex:  % as its first line, TeX doesn't complain about mismatched braces
grub-core/kern/dl.c:    grub_error (GRUB_ERR_BAD_MODULE, "mismatched names");

Doesn't match your message at all.

This message reminds me of grub legacy. Grub2 does not use the stage1/stage2 terminology to my knowledge.

[ruslan]

Sorry, confused versions of grub, since I was trying both - 2.00 and 0.97. 2.00 did not work, it could not boot saying "partition hd(0,msdos1) not found" and showing his rescue shell.

Then I tried 0.97 and it did not work too. Setup(hd0) command is from grub-0.97.

But they both started working when I changed optimization flag to -O1.

[bdubbs@…]

We need to wait for at least one other person to confirm the problem.

[Armin]

Do we want to wait any further?

[bdubbs@…]

No.