Messages in this thread | | | Date | Mon, 7 Jun 1999 19:54:09 +0100 | From | Roger Gammans <> | Subject | Re: RFC: Devices, buses and hotplug |
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In article <199906061910.MAA30421@pizda.davem.net>, David S. Miller <davem@redhat.com> writes > Anyway... one question. Who does the byte swapping, the host CPU > or the peripheral? > > If the answer is 'host CPU', then my response is I can write clean > code that is faster because it takes advantage of big endian > peripheral support. > >Nope, the host CPU does it, but at _ZERO_ cost. You have two ways >usually to get it done: > >1) Load/Store instruction attributes: > >2) MMU translations
Erm. There is a third way it could be done. I don't know about any specific implementations but the Backplane/bus bridge could implement byte swapping merely by the way the data lines are connected.
If I had this problem and was building a motherboard, I would seriously consider going this route, unless there was a good reason not to.
Judging by the rest of this thread I assume no-one does it, which is a shame. But I suppose if endian-ness was never specified.... sigh.
TTFN -- Roger Gammans "If I have trouble installing Linux, something is wrong. Very wrong." -- Linus Torvalds
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