Fw: Grub2 skips standard linux initialization code ?

[devzero]

Hi, 

does somebody know why grub2 skips linux x86 boot/initialization code, leading 
to weird results that a distro`s boot/installation cd behaves different than 
the installed system - with the same kernel ?

it seems that things like vga init and cpu checking are not executed in the 
kernel when booted via grub2.
you need to change linux/initird params to linux16/initrd16 to make grub behave 
like old grub.

regards
roland


> Gesendet: Sonntag, 24. November 2013 um 17:36 Uhr
> Von: address@hidden
> An: address@hidden
> Betreff: Grub2 skips standard linux initialization code ?
>
> Hi, 
> 
> regarding https://bugs.launchpad.net/ubuntu/+source/syslinux/+bug/930447 
> 
> Grub2 "accidentally" heals a problem for systems which cannot boot PAE 
> enabled kernels.  This happens because grub2 apparently jumps into the kernel 
> at a different entry point, so CPUID checking (check for PAE for example) 
> apparently does not occur.
> 
> Here are some 100 affected users (including me) which cannot boot recent 
> Ubuntu (not even lubuntu, which is meant for that) Installation disk on their 
> older hardware, which makes installation a pain.
> 
> This is because Pentium M cpu´s for example often can do PAE, but they 
> incorrectly report.
> 
> The ubuntu installer disc does "traditional" boot via syslinux, whereas the 
> installed system boots via grub2. That explains why you can upgrade from 
> ubuntu 12.04 to 13.10 and have a workable system, but you cannot freshly 
> install 13.10.   The most absurd thing is: You cannot even install Lubuntu or 
> Xubuntu, which is especially designed to be used on older hardware. I guess 
> Pentium M is a process which is still widely used.
> 
> My question is:
> 1. Why does Grub2 think it`s good to skip x86 linux initializiation code? Is 
> that good or bad?
> 2. Besides that, wouldn`t it be extremly helpful to add a quirk or skip 
> routine to the kernel initialization code? (kernelparam: "no-pae-ceck" for 
> example). 
> 
> regards
> roland
>