Subject: kernel load address -- Re: kernel space below 2mbyte
To: None <port-arm@netbsd.org>
From: Toru Nishimura <locore64@alkyltechnology.com>
List: port-arm
Date: 12/29/2004 16:10:24
Fairly outdated response

Jesse Off joff@embeddedARM.com asked;

> I've started working on a port to NetBSD for the TS-7200 ARM board and
> Cirrus Logic EP93XX processor.  I've noticed some of the evbarm boards
> load the kernel text at 2Mbytes from the bottom of SDRAM.  It seems some
> page tables and special stack areas are alloced from that 2Mbyte space
> below the kernel but it seems that whats left of that memory is not put on
> the UVM freelist.  Is the rest of this space intended to be for the kernel
> stack to grow into or am I just missing something?

As already answered, 2MB offset of evbarm kernel load address is the ill-
consequence of bloated monitor colored red.  I've built NFS boot loader
with LIBSA framework whose size ended up with a reasonably small.  It
handsomely arranges initial ARM address space which is suitable to start
NetBSD kernel in a right way, that is, to jump directly to kernel_text: address.
This elimated ugly hack of xxx_start.S accompanying bootfoo offset as large
as 2MB and odd kern.ldscript.  It also brough me ELF symbol table with a
snap quick effort.

Toru Nishimura/ALKYL Technology http://www.alkyltechnology.com