LinuxQuestions.org - Help installing (broadcom) bcm5700 for RedHat AS 3

I just did a clean install of Red Hat AS 3 and I am having problems installing the Broadcom network card (bcm5700).

I installed the RPM Package:
# Install the source RPM package:

rpm -ivh bcm5700-<version>.src.rpm

Change the directory to the RPM path and build the binary driver for your kernel:

cd /usr/src/{redhat,OpenLinux,turbo,packages,rpm ..}
rpm -bb SPECS/bcm5700.spec or rpmbuild -bb SPECS/bcm5700.spec

I ran rpmbuild -bb SPECS/bcm5700.spec and received this error:

Makefiel:46 *** Linux kernel source tree not found. Stop.
Error: Bad exit status from /var/tmp/rpm-tmp.80140(%build)

rpm build errors:
Bad exit status from /var/tmp/rpm-tmp.80140(%build)

So I tried building it from the TAR file:

1. Create a directory and extract the TAR files:

tar xvzf bcm5700-<version>.tar.gz

2. Build the driver bcm5700.o as a loadable module for the running kernel:

cd bcm5700-<version>/src
make
3. Test the driver by loading it:

insmod bcm5700.o
4. Install the driver and man page:

make install

but when I go to the bcm5700-7.3.5/src directory and do a 'make' I get the same error as before which is:

Linux kernel source tree not found. Stop.

What am I missing here? Can anybody help me out? Do I need to install some patches first?

Thanks you!