buildrootschalter/scripts/mkmakefile
Yann E. MORIN aefad5317f Makefile: generate a Makefile wrapper in $(O)
If building out-of-tree, add a Makefile wrapper that calls-out to the real
Makefile with proper args.

Avoids having to pass -C and O= every time we call make.

This is highly inspired from how the Linux kernel does it, and portions of
it have been used. We can't use exactly the same implementation as the
kernel does, because:

 - the script writing the wrapper has been expunged of the few lines
   that were too kernel-related: in buildroot we do not need the version
   string in the wrapper, and we do not have a patchlevel version;

 - "in-tree build" does not have the same meaning for the kernel and for
   buildroot: for the kernel, $(O) point to the $(TOPDIR), while for
   buildroot $(O) points to $(TOPDIR)/output.

For more complete explanations, see:
  http://lists.busybox.net/pipermail/buildroot/2010-September/037815.html

[Peter: minor tweaks]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998 at anciens.enib.fr>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
2010-09-26 23:47:07 +02:00

48 lines
1.0 KiB
Bash
Executable File

#!/bin/sh
# Generates a small Makefile used in the root of the output
# directory, to allow make to be started from there.
# The Makefile also allow for more convinient build of external modules
# Usage
# $1 - Kernel src directory
# $2 - Output directory
test ! -r $2/Makefile -o -O $2/Makefile || exit 0
# Only overwrite automatically generated Makefiles
# (so we do not overwrite buildroot Makefile)
if test -e $2/Makefile && ! grep -q Automatically $2/Makefile
then
exit 0
fi
if [ "${quiet}" != "silent_" ]; then
echo " GEN $2/Makefile"
fi
cat << EOF > $2/Makefile
# Automatically generated by $0: don't edit
lastword = \$(word \$(words \$(1)),\$(1))
makedir := \$(dir \$(call lastword,\$(MAKEFILE_LIST)))
MAKEARGS := -C $1
MAKEARGS += O=\$(if \$(patsubst /%,,\$(makedir)),\$(CURDIR)/)\$(patsubst %/,%,\$(makedir))
MAKEFLAGS += --no-print-directory
.PHONY: all \$(MAKECMDGOALS)
all := \$(filter-out all Makefile,\$(MAKECMDGOALS))
all:
\$(MAKE) \$(MAKEARGS) \$(all)
Makefile:;
\$(all): all
@:
%/: all
@:
EOF