Slimmed down distribution - use wget to fetch .c files

[David N. Welton]

[ please cc replies to me ]

Hello, I was contemplating a way to only install those .c files which
are necessary for your particular compilation.

This would be useful for those who don't wish to download the whole
kernel, with all its various architectures and drivers, for their
single box at home.  There is a potential to save download costs for
those users who pay per minute connection charges.

Basically, I replace a lot of .c files with empty ".w" files, and
create a rule that uses wget to create .c files from them.  I realize
that this may cause some troubles with make dep, but I haven't
encountered any so far.  A possible way around this is to include the
relevant pieces from the .c files in their corresponding .w files
(includes, etc..).

Further improvements might include:

gzipping the files on the server side, getting the $@.gz in the
makefile and then uncompressing it

writing a small daemon that uses http/1.1 to create a persistant
connection.

create a list of all the necessary files and get them at once, using
http/1.1

My slimmed down kernel source tree is available from:

http://static.linuxcare.com/kernel/linux-2.2.10-slim.tar.gz

For a size comparison:
-rw-r--r--   1 davidw   www-data  4862207 Aug 23 12:50 linux-2.2.10-slim.tar.gz 
-rw-rw-r--   1 davidw   davidw   13902979 Jun 16 09:36 linux-2.2.10.tar.gz

Anyway, without further ado, here is my patch, which is actually
rather small:

-------------------- cut here ---------------
diff -r -u -N clean-linux/Rules.make linux/Rules.make
--- clean-linux/Rules.make	Fri Dec 18 14:01:48 1998
+++ linux/Rules.make	Mon Aug 23 12:38:53 1999
@@ -43,6 +43,7 @@
 #
 # Common rules
 #
+include $(TOPDIR)/wget.make
 
 %.s: %.c
 	$(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$@) -S $< -o $@
diff -r -u -N clean-linux/arch/i386/boot/Makefile linux/arch/i386/boot/Makefile
--- clean-linux/arch/i386/boot/Makefile	Sat Jan  2 10:27:52 1999
+++ linux/arch/i386/boot/Makefile	Mon Aug 23 12:38:53 1999
@@ -7,6 +7,7 @@
 #
 # Copyright (C) 1994 by Linus Torvalds
 #
+include $(TOPDIR)/wget.make
 
 AS86	=$(CROSS_COMPILE)as86 -0 -a
 LD86	=$(CROSS_COMPILE)ld86 -0
diff -r -u -N clean-linux/arch/i386/boot/compressed/Makefile linux/arch/i386/boot/compressed/Makefile
--- clean-linux/arch/i386/boot/compressed/Makefile	Mon Jul 20 10:05:15 1998
+++ linux/arch/i386/boot/compressed/Makefile	Mon Aug 23 12:38:53 1999
@@ -3,6 +3,7 @@
 #
 # create a compressed vmlinux image from the original vmlinux
 #
+include $(TOPDIR)/wget.make
 
 HEAD = head.o
 SYSTEM = $(TOPDIR)/vmlinux
diff -r -u -N clean-linux/kernel/Makefile linux/kernel/Makefile
--- clean-linux/kernel/Makefile	Wed May  6 11:01:46 1998
+++ linux/kernel/Makefile	Mon Aug 23 12:38:53 1999
@@ -7,6 +7,8 @@
 #
 # Note 2! The CFLAGS definitions are now in the main makefile...
 
+include ../wget.make
+
 .S.s:
 	$(CPP) -traditional $< -o $*.s
 
diff -r -u -N clean-linux/scripts/ctow.sh linux/scripts/ctow.sh
--- clean-linux/scripts/ctow.sh	Wed Dec 31 16:00:00 1969
+++ linux/scripts/ctow.sh	Mon Aug 23 12:38:53 1999
@@ -0,0 +1,17 @@
+#!/bin/sh
+# Turns .c files into .w files
+
+DIRS="arch
+drivers
+fs
+ipc
+net"
+
+for d in $DIRS; do
+ for cf in `find $d -name "*.c"` ; do
+   wf=`dirname $cf`/`basename $cf .c`.w
+   echo $wf
+   touch $wf
+   rm $cf
+ done
+done
diff -r -u -N clean-linux/wget.make linux/wget.make
--- clean-linux/wget.make	Wed Dec 31 16:00:00 1969
+++ linux/wget.make	Mon Aug 23 12:39:10 1999
@@ -0,0 +1,5 @@
+WGETHOST=static.linuxcare.com
+THIS_SUBDIR:=$(shell echo $(CURDIR)|sed 's|$(TOPDIR)||')
+
+%.c: %.w
+	wget http://$(WGETHOST)/linux/$(KERNELRELEASE)/$(THIS_SUBDIR)/$@ -O $@

The "ctow.sh" is what actually transforms the files from a clean
source tree.

Thanks,
-- 
David N. Welton, Developer, Linuxcare, Inc.
415.354.4878 x241 tel, 415.701.7457 fax
[e-mail], http://www.linuxcare.com/
Linuxcare. At the center of Linux.