On 08.02.2015 22:16, Stefan Tauner wrote: > On Sun, 08 Feb 2015 17:55:10 +0100 > Carl-Daniel Hailfinger <[email protected]> wrote: > >> On 07.02.2015 19:49, Stefan Tauner wrote: >>> Was implemented by SPARC newbies, does (cross-)compile but is not >>> run-tested. >>> >>> Signed-off-by: Stefan Tauner <[email protected]> >> Thanks! >> >> Quoting wikipedia: >>> The endianness of the 32-bit SPARC V8 architecture is purely >>> big-endian. The 64-bit SPARC V9 architecture uses big-endian >>> instructions, but can access data in either big-endian or >>> little-endian byte order, chosen either at the application instruction >>> (load/store) level or at the memory page level (via an MMU setting). >>> The latter is often used for accessing data from inherently >>> little-endian devices, such as those on PCI buses. >> If that is true, we are totally screwed. How can we even begin to >> influence the instructions emitted by the compiler? And if the compiler >> emits bigendian instructions by default, can that be overridden via MMU >> setting? If yes, does Linux use the endianness manipulation via MMU for >> PCI devices, in which case we'd have to treat the architecture as >> littleendian from a flashrom POV? >> >> This is a nightmare. >> > Only if you make it one. :) > Maybe this allows you to sleep better: > https://gcc.gnu.org/ml/gcc-patches/2011-10/msg02240.html
Excellent, this means GCC won't try to screw us. > I am not sure if that "MMU settings" in wikipedia is referring to the > address space identifiers (ASIs), but it definitely screams [citation > needed]. > In general the whole thing looks like a rather exotic if not esoteric > feature added to make porting Windows easier... in any case I am very > confident that it will not be encountered on real machines/OSes. Yay! > So... the only question is if you agree and we commit this before > tagging 0.9.8-rc1 or not. I don't care too much about SPARC support, > but I *do* care about getting the release out. Please respond in a > timely manner. With all this info and your excellent explanations on IRC, I want to say Thank You! Acked-by: Carl-Daniel Hailfinger <[email protected]> Regards, Carl-Daniel _______________________________________________ flashrom mailing list [email protected] http://www.flashrom.org/mailman/listinfo/flashrom
