Re: grub2 code

[Colin Watson]

On Sun, Feb 02, 2014 at 07:25:51PM +0000, Robert Parnell wrote:
> I was just looking at the grub2 source code and saw that
> https://bazaar.launchpad.net/~ubuntu-branches/ubuntu/trusty/grub2/trusty/view/head:/TODO
> <https://bazaar.launchpad.net/%7Eubuntu-branches/ubuntu/trusty/grub2/trusty/view/head:/TODO>
> says to contact with questions.
> I was looking at the source because I encountered a bug on my machine 
> that has been previously reported
> (https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1027694) and
> thought I'd have a look to see if I could find the problem.
> So I have 2 questions:
> 1. Is the code on launchpad the up to date code?

It's an automatically-imported version of the Ubuntu packaging.  It's
up-to-date with what we're shipping, yes, but we do our work in git
these days.  The upstream code is here:

  http://git.savannah.gnu.org/gitweb/?p=grub.git

... and the packaging used by both Debian and Ubuntu is here (the
"experimental" branch is most current):

  http://anonscm.debian.org/gitweb/?p=pkg-grub/grub.git

> 2. Line 177 of
> https://bazaar.launchpad.net/~ubuntu-branches/ubuntu/trusty/grub2/trusty/view/head:/grub-core/boot/i386/pc/startup_raw.S
> <https://bazaar.launchpad.net/%7Eubuntu-branches/ubuntu/trusty/grub2/trusty/view/head:/grub-core/boot/i386/pc/startup_raw.S>
> is a function that flushes the keyboard buffer, could this be what is
> causing the bug?

That seems unrelated.

Ben's patch referenced in https://savannah.gnu.org/bugs/?34547 touches
code that I wrote and that I maintain as a patch, so this would
presumably be my problem to fix.  But I don't understand why Ben's patch
fixes anything related to NumLock.  The code being commented out is
essentially:

        movw    $(GRUB_MEMORY_MACHINE_BIOS_DATA_AREA_ADDR + 0x17), %bx
        andb    $3, (%bx)

... followed by something that tests the condition flags.  But all that
does is test whether either Shift key is held down, not actually set the
NumLock state (see http://www.bioscentral.com/misc/bda.htm).  That is,
it reads from the BIOS Data Area, but it doesn't write to it.

Ben (CCed), could you shed some light on why your patch would fix this?

Thanks,

-- 
Colin Watson                                       address@hidden