With recent toolchain versions, some boards would not build because
or errors like this one (here for ocotea board when building with
ELDK 4.2 beta):
ppc_4xx-ld: section .bootpg [fffff000 -> fffff23b] overlaps section .bss [fffee900 -> fffff8ab]

For many boards, the .bss section is big enough that it wraps around
at the end of the address space (0xFFFFFFFF), so the problem will not
be visible unless you use a 64 bit tool chain for development. On
some boards however, changes to the code size (due to different
optimizations) we bail out with section overlaps like above.

The fix is to add the NOLOAD attribute to the .bss and .sbss
sections, telling the linker that .bss does not consume any space in
the image.

Signed-off-by: Wolfgang Denk <wd@denx.de>

Change all linker scripts to reference the changed driver name 4xx_uart.o.

Note: In most cased all these explicit referencing of these object files
in the linker scripts is not neccessary. Only for manually embedded
environment into the U-Boot image, which is not done is most cases.

Signed-off-by: Stefan Roese <sr@denx.de>

Based on patch by Mike Frysinger, 20 Jun 2006

Modifications are based on the linux kernel approach and
support two use cases:

  1) Add O= to the make command line
  'make O=/tmp/build all'

  2) Set environement variable BUILD_DIR to point to the desired location
  'export BUILD_DIR=/tmp/build'
  'make'

The second approach can also be used with a MAKEALL script
'export BUILD_DIR=/tmp/build'
'./MAKEALL'

Command line 'O=' setting overrides BUILD_DIR environent variable.

When none of the above methods is used the local build is performed and
the object files are placed in the source directory.

Pointed out by Gerhard Jaeger, 31 Aug 2005;
cf. http://sourceware.org/ml/binutils/2005-08/msg00412.html

now handling all 4xx cpu's.
Patch by Stefan Roese, 16 Aug 2005

* Adjust MIPS compiler options at run-time depending on tools version
  ("-march=4kc -mtune=4kc -Wa,-mips_allow_branch_to_undefined" for new,
  "-mcpu=4kc" for old tools)