Re: [PATCH] preserve ARCH and CROSS_COMPILE in the build directory generated Makefile

[Russell King <rmk+lkml@arm.linux.org.uk>]

On Fri, Apr 29, 2005 at 11:00:53PM +0200, Sam Ravnborg wrote:
> On Fri, Apr 29, 2005 at 01:35:33PM +0200, Pavel Pisa wrote:
> > This patch ensures, that architecture and target cross-tools prefix
> > is preserved in the Makefile generated in the build directory for
> > out of source tree kernel compilation. This prevents accidental
> > screwing of configuration and builds for the case, that make without
> > full architecture specific options is invoked in the build
> > directory. It is secure use accustomed "make", "make xconfig",
> > etc. without fear and special care now.
> 
> Hi Pavel.
> I will not apply this path because it introduce a difference when
> building usign a separate output direcory compared to an in-tree build.
> 
> I have briefly looked into a solution where I could add this information
> in .config but was sidetracked by other stuff so I newer got it working.
> 
> The build system for the kernel needs to be as predictable as possible
> and introducing functionality that is only valid when using a separate
> output directory does not help here.

Without it, folk will then do (and this is taken from someone elses
example):

  cd /usr/src
  tar -xjf /path/to/linux-2.6.x.tar.bz
  cd linux-2.6.x
  mkdir -p _build/arm
  cd _build/arm
  cat >GNUmakefile <<EOF
VERSION = 2
PATCHLEVEL = 6
                                                                                
KERNELSRC    := /usr/src/linux-2.6.x
KERNELOUTPUT := /usr/src/linux-2.6.x/_build/arm
                                                                                
MAKEFLAGS += --no-print-directory
                                                                                
ARCH            = arm
#CROSS_COMPILE  = arm-unknown-linux-gnu-
CROSS_COMPILE   = arm-linux-
                                                                                
all:
        $(MAKE) ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE) -C $(KERNELSRC) O=$(KERNELOUTPUT)
                                                                                
%::
        $(MAKE) ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE) -C $(KERNELSRC) O=$(KERNELOUTPUT) $@
EOF
  make xconfig
  make

which I think you'll agree is far worse.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core