Re: reporting amount of available memory (and acting on it) from grub?

[Andrei Borzenkov]

06.01.2016 11:50, Daniel Kahn Gillmor пишет:
> Hi grub folks--
> 
> Is there a way that a grub script (or the grub commandline) can report
> the amount of available memory?
> 
> It seems like it would be useful in situations like a liveCD or bootable
> image that might want to warn the user up front if the available RAM is
> smaller than the advertised minimum.  (e.g. Tails or debirf)
> 
> Currently, when systems boot with less memory than their minimums, they
> often end up with a kernel dump or something similarly unintelligible to
> most users.  A well-crafted grub configfile for such an image could
> provide the user with something more understandable, or at least warn
> the user before continuing that the available memory is believed to be
> inadequate.
> 
> I could also imagine a use case like an automated boot process that
> selects some x86_64 kernel or boot options on machines with > 4GiB of
> RAM and plain x86 for machines with less.
> 
> any pointers to how to do this?
> 

Look at lsmmap; in principle, it could be extended to report totals and
set value to variable, or another command added.