Subject: Re: Cross-compiler-HOWTO
To: Allen Briggs <>
From: Andrew Cagney <>
List: tech-ports
Date: 02/08/1996 02:08:39
Excerpts from mail: 22-Jan-96 Re: Cross-compiler-HOWTO
Chris_G_Demetriou@NIAGAR (765)

> Actually, what _i_ would most like to see come out of this is:
> 	(1) a document which details how to cross-compile the system,
> 	    or at least the kernel, and

Below are some of the notes from PSIM (PowerPC simulator) they explain
how to build NetBSD binaries hosted on Solaris/x86.  As for the kernel,
it linked ....

BTW: I believe that the problems with make were recently fixed. 
Unfortunatly the remote ftp server I use has been playing up.  Oh and
some of the files I refer to won't be available until later today.

> 	(2) from people who've done cross-compiling to the port
> 	    maintainers, a set of 'suggested changes' to makefiles,
> 	    etc., to make it work.  e.g. "change this compile rule
> 	    to specify the cc that builds a native binary, change this
> 	    compile rule to specify the cc that builds the
> 	    cross-compiled bin," etc.  I think a list of things
> 	    that need to be done, and diffs for at least one port,
> 	    would be most useful for getting Real Live Support
> 	    for cross-compilation in the tree.

o	I believe the problem building make has been fixed. 

o	The build has a chicken/egg problem with header files.
	You will notice that in the below I hand install some .h
	files to avoid problems.

o	the makefiles insist on root and berkeley versions of
	some commands (I get around this with wrapper
	scripts - see below).

o	the include directory wants to use pax and *not* follow
	soft links.  There is a patch to change that to both use
	find and be a bit more tolerant towards strange directories.

Other than those there really are not that many problems.  Probably the
only reall suggestion is to ensure that for all machine code library
functions there is both a matching C version and it is regularly tested
(I noticed in the kernel that many machine code functions could be
prototyped using C).




For a UEA to be useful it needs a supporting run-time environment.
PSIM implements a runtime environment based on the NetBSD system call

More than any thing, this user level emulation was the first
implemented because I happened to have the NetBSD source code lying
lying around.


This requires the NetBSD-1.1 source tree online.  It can either be
obtained vi ftp:

	try  or

Alternatively obtain one of the NetBSD cdrom's.  Patches to this source
tree that fill out much of the PowerPC code are available in:

Fetch everything in that directory - diffs, tar archives and scripts.
In addition a patch to binutils is in:

Finally you'll require a compiler and assembler/linker:



These notes are based on an installation performed on a Solaris2/x86
host.  For other hosts and other configurations, the below should be
considered as a guideline only.

	o	Sanity check

		I assume that you have already obtained the NetBSD-1.1 source
		code and unpacked it into the directory bsd-src.  While the
		full NetBSD source tree may not be needed, things are easier
		if it is all online.

		$ cd .../scratch
		$ ls -1

	o	Unpack the bsd source code (if you haven't already)

		$ cd .../scratch
		$ mkdir bsd-src
		$ cd bsd-src
		$ for d in /cdrom/bsdisc_12_95_disc2/NetBSD-1.1/source/*11
                    echo $d
                    cat $d/*.?? | gunzip | tar xf -

		Flatten the directory structure a little.

		$ mv usr/src/* .
		$ rmdir usr/src usr
		$ cd ..

	o	Unpack/build/install binutils

		$ cd .../scratch
		$ gunzip < binutils-2.6.tar.gz | tar xf -
		$ cd binutils-2.6

		Optionally apply the note patch

		$ gunzip ../binutils-2.6+note.diff.gz | patch

		Then continue with the build

		$ ./configure --target=powerpc-unknown-eabi \
		$ make
		$ make install
		$ cd ..
		$ rm -rf binutils-2.6

		This has the intended side effect of partially populating
		the psim directory tree which makes follow on steps easier.

	o	Fill out the install directory with a few additions (if
		install -d works, this can be simplified).

		$ mkdir \
                    /applications/psim/bsd-root \
                    /applications/psim/bsd-root/usr \
                    /applications/psim/bsd-root/usr/share \
                    /applications/psim/bsd-root/usr/share/doc \
                    /applications/psim/bsd-root/usr/share/doc/psd \
                    /applications/psim/bsd-root/usr/share/doc/psd/19.curses \
                    /applications/psim/bsd-root/usr/include \
                    /applications/psim/bsd-root/usr/lib \

	o	Make the bsd and gnu include directories point to the same

		GCC expects include files to be in one location while the
		bsd install expects them in a second.  The link is in
		the direction below because bsd's install also insists on
		a directory (not a link) for its install destination.

		$ ln -s ../bsd-root/usr/include \

	o	Build/install Berkeley make

		In building Berkeley make from the NetBSD-1.1 source tree
		a number of problems may be encountered.

		These problems have been fixed in NetBSD-current (after
		4/2/96 (ie start Feb)) you should probably obtain that
		version of make.  Alternatively, you can try following the
		notes below that got make working on a Solaris-2.5/x86

		$ cd .../scratch
		$ cd bsd-src/usr.bin/make
		$ pwd

		Copy/stub some additional include files that your host may not

		$ cp ../../include/ranlib.h ranlib.h
		$ mkdir sys
		$ cp ../../sys/sys/cdefs.h sys/cdefs.h
		$ mkdir machine
		$ touch machine/cdefs.h

		Edit/fix some of the BSDisms. The patch file indicated
		contains fixes I found when compiling on my host, your
		host will probably differ.

		$ gunzip < ../../../clayton.usr.bin.make.diff.gz | patch

		Build it with some extra flags (again your flags will differ):

		$ make -f Makefile.boot CC='gcc -g -DPOSIX'

		With bmake built, install it into the target specific bin

		$ cp bmake /applications/psim/powerpc-unknown-eabi/bin/make
		$ cd ../../.. 

	o	Patch/install Berkeley make's include (mk) files.

		$ cd .../share
		$ cd bsd-src/share
		$ tar cf - mk | ( cd /applications/psim/bsd-root/usr/share \
                     && tar xf - )
		$ cd ../..

	o	Set up a number of wrapper scripts for bmake so that it works.

		In addition to needing BSD make the build process assumes
		a number of BSD specific commands.  To get around this
		several wrapper scripts are available.

		powerpc-unknown-eabi-make (clayton.make)

			Front end to Berkeley make setting it up for a
			cross compilation


		chown (clayton.chown)

			Wrapper that does not do any thing.
			Avoids the need to be root when installing.


		install (clayton.install)

			Wrapper to strip away a number of bsd specific install


		lorder (clayton.lorder)

			Tweaked lorder script that will use nm etc from


	o	Apply the remaining patches for the BSD source tree

		$ cd .../scratch
		$ cd bsd-src
		Diffs are applied using something like:

		$ gunzip < ../clayton-include-960203.diff.gz | more

		The patch to sys/dev/pci/ncr.c.rej might fail.

		The tar archives have a different problem, you need
		to remove the `src' prefix.  I used

		$ ln -s . src
		$ gunzip < ../clayton-lib-960203.tar.gz | tar xtf -

		So that src/xxx unpacked into ./xxx

		$ cd ..

	o	Install the include files

		$ cd .../scratch
		$ cd bsd-src/include
		$ powerpc-unknown-eabi-make install
		$ cd ../..

	o	Install a few other include files.

		As with building libnew, the bsd build process has
		several include file problems.

		$ cd .../scratch
		$ cd bsd-src
		$ cp gnu/lib/libg++/g++-include/values.h \
		$ cp lib/libcurses/curses.h \
		$ cd ..

	o	Build/install gcc

		$ cd .../scratch
		$ gunzip < gcc-2.7.2,tar.gz | tar xf -
		$ cd gcc-2.7.2

		GCC and BSD (for PowerPC) have a conflicting type
		declaration.  The patch below gets around this

		$ gunzip < ../gcc-2.7.2+sys-types.diff.gz | patch

		Other than that, assuming the include files installed
		okay, the rest should be fine ....

		$ ./configure --target=powerpc-unknown-eabi \
		$ make CC=gcc
		$ make CC=gcc install
		$ cd ..
		$ rm -rf gcc-2.7.2

	o	Build/install the Berkeley library:

		$ cd .../scratch
		$ cd bsd-src/lib
		$ powerpc-unknown-eabi-make
		$ powerpc-unknown-eabi-make install
		$ cd ../..

		If you encounter problems try the following: an include
		file not yet installed; a directory not yet created;
		running the hosts version of a program instead of a
		bsd version.

	o	Build/run a simple BSD program

		$ cd .../scratch
		$ cd bsd-src/usr.bin/printenv
		$ powerpc-unknown-eabi-make
		$ powerpc-unknown-eabi-run printenv