u-boot/drivers/bios_emulator
Masahiro Yamada 9e4140329e kbuild: change out-of-tree build
This commit changes the working directory
where the build process occurs.

Before this commit, build process occurred under the source
tree for both in-tree and out-of-tree build.

That's why we needed to add $(obj) prefix to all generated
files in makefiles like follows:
  $(obj)u-boot.bin:  $(obj)u-boot

Here, $(obj) is empty for in-tree build, whereas it points
to the output directory for out-of-tree build.

And our old build system changes the current working directory
with "make -C <sub-dir>" syntax when descending into the
sub-directories.

On the other hand, Kbuild uses a different idea
to handle out-of-tree build and directory descending.

The build process of Kbuild always occurs under the output tree.
When "O=dir/to/store/output/files" is given, the build system
changes the current working directory to that directory and
restarts the make.

Kbuild uses "make -f $(srctree)/scripts/Makefile.build obj=<sub-dir>"
syntax for descending into sub-directories.
(We can write it like "make $(obj)=<sub-dir>" with a shorthand.)
This means the current working directory is always the top
of the output directory.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Gerhard Sittig <gsi@denx.de>
2014-02-19 11:07:50 -05:00
..
include drivers: delete unused header files 2014-01-24 16:59:07 -05:00
x86emu Consolidate bool type 2013-04-01 16:33:52 -04:00
atibios.c Consolidate bool type 2013-04-01 16:33:52 -04:00
besys.c biosemu: include <asm/io.h> header 2013-04-02 16:23:35 -04:00
bios.c biosemu: include <asm/io.h> header 2013-04-02 16:23:35 -04:00
biosemu.c Update Freescale copyrights to remove "All Rights Reserved" 2009-07-29 09:59:22 +02:00
biosemui.h Update Freescale copyrights to remove "All Rights Reserved" 2009-07-29 09:59:22 +02:00
Makefile kbuild: change out-of-tree build 2014-02-19 11:07:50 -05:00