[OpenBIOS] [RFC 2/3] PPC: Mimic Apple's OpenFirmware behaviour if a divide by zero occurs.

[Mark Cave-Ayland]

As reported by Amadeusz Sławiński using a real Mac, if anything is divided by
zero then we should return zero:

0 > 2 0 /  ok
1 > u. 0  ok

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland at ilande.co.uk>
---
 openbios-devel/arch/ppc/ppc.fs |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/openbios-devel/arch/ppc/ppc.fs b/openbios-devel/arch/ppc/ppc.fs
index 6995ba9..212894d 100644
--- a/openbios-devel/arch/ppc/ppc.fs
+++ b/openbios-devel/arch/ppc/ppc.fs
@@ -53,5 +53,12 @@
 \ other
 \ -------------------------------------------------------------------------
 
+\ Override divide by zero handling
+\ Tests indicate that Apple's OF implementation returns a single value of 0
+
+: (ppc-div-by-zero-handler) 3drop 0 0 0 ;
+
+['] (ppc-div-by-zero-handler) to (div-by-zero-handler)
+
 \ Set by BootX when booting Mac OS X
 defer spin
-- 
1.7.10.4