The best way to build and package this code for apt is to:

* Check it out from the version control system.  Only svn is supported today
  by the Makefile.
* cd cp210x # to go into the top level directory checked out
* make
* cd build
* sudo pbuilder update # if needed
* sudo pbuilder build $(ls -t cp210x-module*dsc | head -1)
* scp /var/cache/pbuilder/result/cp210x-module-*-0tmi* \
    aptuser@aptpackageserver:/tmp/
* ssh aptuser@aptpackageserver
* cd /tmp
* reprepro -Vb /var/local/aptrepo/ubuntu include hardy cp210x*.changes
* rm cp210x*

Build a .deb locally is quite a bit simpler and faster:

* Check out the code
* cd cp210x
* make binary
* # find the .deb in the build/ directory
* # To install locally, FIRST REMOVE all cp210x-module packages installed. Then,
* sudo dpkg -i build/cp210x-module*.deb

The cp210x.ko file can be built and installed from the source directory as
well, but this isn't recommended:

* Check out the code
* cd cp210x/src
* ./configure -kver $(uname -r)
* make -f Makefile.go all
* # The binary is called cp210x.ko
* # To install,
* chmod a+x installmod
* sudo make -f Makefile.go install
* # To clean the source tree,
* sudo make -f Makefile.go clean

Older kernels are supported, but require one to check out the pre2.6.24
branch from the repo, then follow any of the steps above.  You may have to
edit cp210x.c and replace:
	#include "usb-serial.h"
with:
	#include "/path/to/usb-serial.h"
before building.