CSPPC233Fix

Short:        Workaround for CSPPC/233 hardware bug
Author:       lesueur@club-internet.fr, frank@phoenix.owl.de (Frank Wille & Emmanuel Lesueur)
Uploader:     frank phoenix owl de
Type:         driver/other
Requires:     powerpc.library or ppc.library
Architecture: m68k-amigaos

Some CyberStormPPC 604e/233MHz boards seem to suffer from annoying
random crashes under WarpOS as well as under PowerUp. They might be
caused by some kind of hardware bug, which sets bit 0 or bit 2 of the
PowerPC's LR register in certain situations. This will result into an
instruction access fault, when a program returns from a sub routine.

If you ever got an instruction access exception where the first digit
of LR is not '0', then this program might solve most of your troubles.

Whether this problem comes from a defective board, or a bad power supply,
or from too much heat is unknown. But surprisingly it only affects
CSPPCs with a 233 MHz CPU. 200 MHz is fine, I have one for comparison!

This archive contains two exception handlers, one for PowerUp
(CSPPC233Fix_ppc) and one for WarpOS (CSPPC233Fix_wos), which reset
those trashed bits in case of an exception which is recognized as the
"LR-Bug problem". The PPC program is able to continue after LR was fixed.


USAGE:

CSPPC233Fix_ppc (PowerUp version):
----------------------------------
  Can be started from CLI and from Workbench.
  CLI Usage:
      LRBug NOREQ/S,QUIET/S,NOWAIT/S

  NOREQ: don't ask before attempting to restart a task.
  QUIET: don't write messages with kprinf() when restarting a task.
  NOWAIT: don't install a handler, just restart crashed tasks and quit.

  WB Usage:
      Tooltypes NOREQ, QUIET, and NOWAIT, with the same meaning.

  To remove the handler, send a CTRL-C.

CSPPC233Fix_wos (WarpOS version):
---------------------------------
  Just start from CLI. No options. To remove the handler, press CTRL-C.
  Whenever an LR-Bug occurs, the hit will be printed to stdout. If
  you don't want that, redirect output to NIL:. All other exceptions
  will be invoke the WarpOS exception window, as usual.


REBUILD:

The full source text of both programs is included and a makefile is
provided to rebuild them with vbcc. The PowerUp version can also be
compiled with SAS/C and gcc. The WarpOS version with StormC (gcc-WarpOS
is not recommended for an exception handler, because of different ABIs).