I have and use a Cobalt Qube2 (64-Bit MIPS little-endian).
It uses a specific version of the Linux kernel 2.0.34 with backported fixes from 2.1.111.
I have compiled MySQL 3.23.35 with these options:
./configure --disable-assembler \
            --prefix=/usr/local/mysql \
            --disable-shared \
            --with-low-memory \
            --with-mysqld-ldflags="-all-static" \
            --with-client-ldflags="-all-static" \
            --with-mysqld-user=mysql
(These settings are based on someone else's settings for compiling MySQL 3.22.32 on Raq2/Qube2)

PHP4.0.3pl1:
./configure --with-mysql=/usr/local/mysql \
            --with-apxs=/usr/sbin/apxs \
            --with-zlib \
            --enable-track-vars \
            --enable-trans-sid \
            --enable-ftp \
            --with-mm=/usr/local/lib
            --with-xml

The message I get when trying to run Apache with this newly compiled module is:

Syntax error on line 239 of /etc/httpd/conf/httpd.conf: 
Cannot load /usr/lib/apache/libphp4.so into server: /usr/local/mysql/lib/mysql/libmysqlclient.so.10: undefined symbol: my_message_no_curses 

I have run 'ldd' on libphp4.so and libmysqlclient.so.10 and there are no undefined symbols in either of them.