At91rm9200 how to start with FreeBSD

[Olivier Houchard]

Hi,

On Wed, Nov 29, 2006 at 01:07:16PM -0800, Zuy wrote:
> 
> I found bootstrap tools and kernel config files in FreeBSD6.2.
> So I decided to try to compile kernel for At91RM9200 the same way as I do
> for I386 configuration.
> As far as I do not have all source files installed I have to use traditional
> way for building kernel.
> 
> zuy_bsd#  cd /usr/src/sys/arm/conf
> zuy_bsd# /usr/sbin/config KB920X
> Kernel build directory is ../compile/KB920X
> Don't forget to do ``make cleandepend; make depend''
> zuy_bsd# cd ../compile/KB920X
> zuy-bsd# make cleandepend
> rm -f .depend
> zuy-bsd# make depend
> cc -c -O -pipe -Wall -Wredundant-decls -Wnested-externs ....... # I cut
> option to make my post shorter 
> `-mcpu=' is deprecated. Use `-mtune=' or '-march=' instead.
> ../../../i386/i386/genassym.c:1: error: bad value (arm9) for -mtune= switch
> *** Error code 1
> 
> Stop in /usr/src/sys/arm/compile/KB920X.
> 
> I think this error means that by default GCC in FreeBSD6.2 does not support
> compilation for ARM architecture.
> I have two ideas how to enable this support.
> 1. Download lates version of GCC and compile it with cross compiler for ARM.
> 2. Install /usr/ports/devel/arm-elf-gcc295
> I found that a lot of people do not advice to change standart compiler with
> new one. It can cause problems with future kernel building. That is why I'm
> not sure that the first way is correct.
> The second way installs ARM support but for old version of compiler. That I
> think is not good as well.
> 

You can build an arm cross-compiler from the system sources as described here :
http://people.FreeBSD.org/~cognet/freebsd_arm.txt
Using the new official way to build the kernel, with make buildkernel,
should work for cross-compiling too :
I think you first need to do
make TARGET_ARCH=arm kernel-toolchain
and then you should be able to do make TARGET_ARCH=arm KERNCONF=YOURFILE 
buildkernel
But I do not use this method, so I can't swear it's the exact things to do.

Cheers,

Olivier