Fix problem with only partially cleared .bss segment
* Patch by Rune Torgersen, 12 May 2003:
get PCI to work on a MPC8266ADS board; incorporate change to
cpu/mpc8260/pci.c to enable overrides of PCI memory parameters
update for CrayL1 board
* Patch by Pantelis Antoniou, 21 Apr 2003:
add boot support for ARTOS (a proprietary OS)
* Patch by Steven Scholz, 11 Apr 2003:
Add support for RTC DS1338
* Patch by Rod Boyce, 24 Jan 2003:
Fix counting of extended partitions in diskboot command