Subject: Re: Advice on adding support for a new Platform
To: Thomas J. Merritt <>
From: Chris Gilbert <>
List: port-arm
Date: 06/07/2001 00:11:43
On Wednesday 06 June 2001  9:06 pm, Thomas J. Merritt wrote:
> I interested in porting NetBSD/ARM to a platform based upon the Cirrus
> Logic EP7312.  The EP7312 has an ARM 720T core plus a bunch of peripherals
> and is similar to the EP7209.  The board is running OpenFirmware. 
> OpenFirmware is able to net load the kernel as an ELF image.  I would
> appreciate any advice on how to attack the port.

I presume that the 720T is a thumb based chipset (not looked for the spec on 
it yet)  So certainly an issue is that we currently don't have support for 
thumb in NetBSD (not sure if gcc can do Thumb either).  If it's not Thumb, it 
maybe a matter of adding the checks for it's CPU ID and with a bit of luck 
it'll look enough like an ARM7 core that we'll work with it :)

Doing an ELF kernel shouldn't be too bad as I believe that arm26 is an ELF 
kernel, so we do have ELF arm stuff around, however we're still not that 
close to doing full blown ELF on arm32, it would probably take some kind of 
cross compiler for the kernel. And some of the asm files would need a bit of 
work to cope with ELF.

On the openfirmware side we already have generic support for openfirmware 
(see the shark/dnard for an existing arm version)  So that should make life