Crosscompiling with distcc HOWTO
================================

Purpose:
--------
croscompiling of sourcecode in general including NetBSD's source 
tree and NetBSD's pkgsrc packages using `pkgsrc/devel/distcc'

Note that this current setup is not intended for build builds as it might
confuse the buildbuild system.

Terminology:
------------

There are multiple terminologies in use for cross building.  In pkgsrc, we use

  build platform: the system on which you are doing the compilation of packages

  target platform: the system on which you will run the packages

(An alternative terminology is that used by autoconf:

  build: as above
  host: as "target", above
  target: the architecture that the cross-built compiler produces code for

pkgsrc chooses the more simple build/target terms because the Canadian
Cross situation is not common in pkgsrc.  Partially because of the
potential for confusion with autoconf's terminology, we avoid the word
"host".

Target machine setup:
---------------------
1) install `pkgsrc/devel/distcc' package.

2) install helper script "use-distcc" in f.e. /usr/local/bin/:
	---------
	#!/usr/pkg/bin/tcsh

	setenv PATH "/usr/distcc/bin:$PATH"
	setenv CC gcc
	---------

3) create directory "/usr/distcc/bin" contents with softlinks :
	lrwxr-xr-x  1 root  wheel   20 Sep 16 02:58 c++@ -> ../../pkg/bin/distcc
	lrwxr-xr-x  1 root  wheel   20 Sep 16 02:57 cc@ -> ../../pkg/bin/distcc
	lrwxr-xr-x  1 root  wheel   20 Sep 16 02:58 g++@ -> ../../pkg/bin/distcc
	lrwxr-xr-x  1 root  wheel   20 Sep 16 02:57 gcc@ -> ../../pkg/bin/distcc


Helper machine setup:
---------------------
1) install `pkgsrc/devel/distcc' package.

2) create a crosscompiler to compile from any architecture to NetBSD/sparc, 
go to the NetBSD src dir and run :
	./build.sh -a sparc -m sparc -T /usr/gcc-cross-sparc/ tools

this will create a directory called /usr/gcc-cross-sparc/ with the 
crosscompilation tools.

3) install helper script "START-distcc' 
	------------
	#!/usr/pkg/bin/tcsh

	setenv PATH "/usr/gcc-cross-sparc/sparc--netbsdelf/bin/:$PATH"
	setenv DISTCC_VERBOSE 1

	distccd -a 192.168.0.137/24  --listen 192.168.0.137 -p 3632
	-----------
this will start the `distcc' daemon to listen on the 192.168.0/24 network 
and listen on 192.168.0.137 specificly and on port 3632 (why doesn't it do 
this on default?)


Compilation of sources (not pkgsrc):
------------------------------------
1) on each helper machine run the `START-distcc' script

2) on the target machine (replace helper1, helper2 etc. by the names/ip 
addresses of the helper machines) :
	-----------
	source /usr/local/bin/use-distcc
	setenv DISTCC_HOSTS "helper1 helper2 helper3"
	cd .../sourcedir
	make -j2 target
	-----------


Compilation of pkgsrc packages:
-------------------------------
1) on each helper machine run the `START-distcc' script

2) on the target machine, do NOT run the `use-distcc' script, go to the
package dir and set :

set the helpers (,lzo addition sets compression of the data transport):
	setenv DISTCC_HOSTS "helper1 helper2 helper3,lzo"

instruct pkgsrc to use distcc:
	setenv PKGSRC_COMPILER "distcc gcc"

set the concurrency level (not all packages allow this)
	setenv BUILD_MAKE_FLAGS "-j2"

compile/update package
	make update

thats all :)