Signed-off-by: NWolfgang Denk <wd@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.

- Add IXP4xx NPE ethernet MAC support
- Add support for Intel IXDPG425 board
- Add support for Prodrive PDNB3 board
- Add IRQ support
Patch by Stefan Roese, 23 May 2006

[This patch does not include cpu/ixp/npe/IxNpeMicrocode.c which still
 sufferes from licensing issues. Blame Intel.]

Patch by Yuli Barcohen, 12 Dec 2004

Minor code cleanup.

- remove ZPC.1900 board-specific flash driver;
  switch the port to generic CFI driver;
- port clean-up

  add support for Zephyr Engineering ZPC.1900 board

* Patch by Anders Larsen, 23 Sep 2003:
  add CMD_PORTIO to CFG_CMD_NONSTD (commands in question are only
  implemented for the x86 architecture)

  - remove trailing white space, trailing empty lines, C++ comments, etc.
  - split cmd_boot.c (separate cmd_bdinfo.c and cmd_load.c)

* Patches by Kenneth Johansson, 25 Jun 2003:
  - major rework of command structure
    (work done mostly by Michal Cendrowski and Joakim Kristiansen)