EFI_STAGING_SIZE - what exactly is limited and trouble with high value

[Subbsd]

On Thu, Nov 10, 2016 at 11:59 PM, Subbsd <subbsd at gmail.com> wrote:
> Hello,
>
> After https://lists.freebsd.org/pipermail/svn-src-stable-11/2016-September/000503.html
> commits and with same reason as
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=209944 ( i have
> mfs-based images more than ~512M size) , I tried to increase
> EFI_STAGING_SIZE up to 1024 ( my server have 16 GB RAM ) and got  a
> system hang with follow message:
> --
> Booting ...
> Start @ 0xffffffff80301000 ...
> Efi framebuffer information:
> addr, size 0xe9000000, 0x500000
> dimensions 1280 x 1024
> stride 1280
> masks 0x00ff0000 0x0000ff00, 0x000000ff, 0xff000000
> ---
>
> If i reduce EFI_STAGING_SIZE to 768, system booted as usual.
>
> Can someone explain -- what exactly is limited EFI_STAGING_SIZE in
> 1GB, which leads boot to freeze ? This is normal ? And why this value
> can not be dependent from hw.physmem ?
>
> We increase EFI_STAGING_SIZE by 16 Megabytes, from 48 to 64, but i'm
> sure, and some may have more than 64 MB


Forget to attach screenshot with EFI_STAGING_SIZE after magic 768
value: http://pasteboard.co/pGgkKHOO7.jpg