Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/Documentation/smart-config.txt b/Documentation/smart-config.txt
new file mode 100644
index 0000000..c9bed4c
--- /dev/null
+++ b/Documentation/smart-config.txt
@@ -0,0 +1,102 @@
+Smart CONFIG_* Dependencies
+1 August 1999
+
+Michael Chastain <mec@shout.net>
+Werner Almesberger <almesber@lrc.di.epfl.ch>
+Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>
+
+Here is the problem:
+
+ Suppose that drivers/net/foo.c has the following lines:
+
+ #include <linux/config.h>
+
+ ...
+
+ #ifdef CONFIG_FOO_AUTOFROB
+ /* Code for auto-frobbing */
+ #else
+ /* Manual frobbing only */
+ #endif
+
+ ...
+
+ #ifdef CONFIG_FOO_MODEL_TWO
+ /* Code for model two */
+ #endif
+
+ Now suppose the user (the person building kernels) reconfigures the
+ kernel to change some unrelated setting. This will regenerate the
+ file include/linux/autoconf.h, which will cause include/linux/config.h
+ to be out of date, which will cause drivers/net/foo.c to be recompiled.
+
+ Most kernel sources, perhaps 80% of them, have at least one CONFIG_*
+ dependency somewhere. So changing _any_ CONFIG_* setting requires
+ almost _all_ of the kernel to be recompiled.
+
+Here is the solution:
+
+ We've made the dependency generator, mkdep.c, smarter. Instead of
+ generating this dependency:
+
+ drivers/net/foo.c: include/linux/config.h
+
+ It now generates these dependencies:
+
+ drivers/net/foo.c: \
+ include/config/foo/autofrob.h \
+ include/config/foo/model/two.h
+
+ So drivers/net/foo.c depends only on the CONFIG_* lines that
+ it actually uses.
+
+ A new program, split-include.c, runs at the beginning of
+ compilation (make bzImage or make zImage). split-include reads
+ include/linux/autoconf.h and updates the include/config/ tree,
+ writing one file per option. It updates only the files for options
+ that have changed.
+
+ mkdep.c no longer generates warning messages for missing or unneeded
+ <linux/config.h> lines. The new top-level target 'make checkconfig'
+ checks for these problems.
+
+Flag Dependencies
+
+ Martin Von Loewis contributed another feature to this patch:
+ 'flag dependencies'. The idea is that a .o file depends on
+ the compilation flags used to build it. The file foo.o has
+ its flags stored in .flags.foo.o.
+
+ Suppose the user changes the foo driver from resident to modular.
+ 'make' will notice that the current foo.o was not compiled with
+ -DMODULE and will recompile foo.c.
+
+ All .o files made from C source have flag dependencies. So do .o
+ files made with ld, and .a files made with ar. However, .o files
+ made from assembly source do not have flag dependencies (nobody
+ needs this yet, but it would be good to fix).
+
+Per-source-file Flags
+
+ Flag dependencies also work with per-source-file flags.
+ You can specify compilation flags for individual source files
+ like this:
+
+ CFLAGS_foo.o = -DSPECIAL_FOO_DEFINE
+
+ This helps clean up drivers/net/Makefile, drivers/scsi/Makefile,
+ and several other Makefiles.
+
+Credit
+
+ Werner Almesberger had the original idea and wrote the first
+ version of this patch.
+
+ Michael Chastain picked it up and continued development. He is
+ now the principal author and maintainer. Please report any bugs
+ to him.
+
+ Martin von Loewis wrote flag dependencies, with some modifications
+ by Michael Chastain.
+
+ Thanks to all of the beta testers.