[OpenBIOS] [RFC 2/3] ppc64: Switch to 64-bit cell size
Segher Boessenkool
segher at kernel.crashing.org
Sat May 28 20:30:42 CEST 2011
> If I recall correctly what I said, the device-tree property cell size
> is _always_ 32-bit, regardless of what the internal cell size is.
Don't call that "cell size" :-) The OF standard calls it "a 32-bit
integer
as encoded by encode-int".
> - The cell size presented to FCode version 2 drivers (plug-in cards),
> which is emulated to be 32 bits.
Do you mean the size of (lit) here? That's 32-bit signed always, yes.
The
FCode cell size is the same as the Forth cell size. Most FCode programs
written for 32-bit systems work as-is on 64-bit systems; some need some
fixes. Programs that need 64-bit numbers (for example, for devices that
have 64-bit registers) need some careful coding.
Segher
More information about the OpenBIOS
mailing list