Re: [PATCH] Increase number of e820 entries hard limit from 32 to 128

[Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>]

On Fri, Apr 22, 2005 at 06:51:59PM -0700, Linus Torvalds wrote:
> On Fri, 22 Apr 2005, Venkatesh Pallipadi wrote:
> > The specifications that talk about E820 map doesn't have an upper limit
> > on the number of E820 entries. But, today's kernel has a hard limit of 32.
> > With increase in memory size, we are seeing the number of E820 entries
> > reaching close to 32. Patch below bumps the number upto 128. 
> 
> Hmm. Anything that changes setup.S tends to have bootloader dependencies. 
> I worry whether this one does too..
> 

The setup.S change in this patch should be OK. As it is adding to the 
existing zero-page and keeping it within one page. I tested it on systems 
with grub, adding some dummy E820 entries and it worked fine.

However, there is another place that needs to be changed. Boot loaders
also calls E820 while booting directly with vmlinux (instead of usual 
bzImage - which is handled by this patch) and that needs to change to 
incorporate more E820 entries. But, there we may need more changes, to 
the boot protocol version and the like. On a side note, looking at the 
grub source, it seems to have a limit of 50 entries today, which doesn't 
agree with current 32 entry limit in the kernel. Not sure why grub has 
this different limit though.

Thanks,
Venki