[OpenBIOS] [RFC 2/3] ppc64: Switch to 64-bit cell size

Segher Boessenkool segher at kernel.crashing.org
Sat May 28 18:02:47 CEST 2011

> I'm saying that changing sizeof(cell) will change the device tree:
> drivers/escc.c:escc_add_channel
> [...]
>     cell props[2];
> [...]
>     props[0] = IO_ESCC_OFFSET + offset * 0x20;
>     props[1] = 0x00000020;
>     set_property(dnode, "reg", (char *)&props, 2 * sizeof(cell));
> So while the guest expects reg to be 2 32-bit numbers, it suddenly 
> gets 4 32-bit numbers that don't make sense. IIUC to the guest, any DT 
> property is nothing more than a stream of bytes.

That code seems to fail for little-endian systems as well.  I recommend
you use C accessor functions similar to the Forth words to build (and
read) properties, they are very convenient and easy to use (encode-int
and friends).


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