Module Name:	syssrc
Committed By:	kleink
Date:		Thu May  2 16:47:49 UTC 2002

Modified Files:
	syssrc/sys/arch/powerpc/powerpc: trap_subr.S

Log Message:
* On the 601, obliterate all BAT entries when returning from kernel to
  userlevel; this is necessary due to the 601, unlike other 6xx, having
  no concept of separated Valid_user vs. Valid_supervisor for BATs.
* When crossing the kernel/userlevel boundary, have platform-provided
  hooks set up the two fixed BAT entries, and possibly additional
  segment registers to redeem the 601's BAT limitations.

Both of the above are only built if the $MACHINE provides these hooks,
sparing others the pain.


To generate a diff of this commit:
cvs rdiff -r1.20 -r1.21 syssrc/sys/arch/powerpc/powerpc/trap_subr.S

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.