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.
Move most of the timer interrupt related PPC code to ppc_lib/interrupts.c
* Patch by Anders Larsen, 17 Sep 2003:
Bring ARM memory layout in sync with the documentation:
stack and malloc-heap are now located _below_ the U-Boot code
