Hi, On Fri, May 15, 2009 at 02:55:57PM +0100, Ben Dooks wrote: > On Fri, May 15, 2009 at 02:51:05PM +0100, Jamie Lokier wrote: > > Eek, can you say a bit more about the ARM EABI mismatch? > > > > I would like to run a shiny modern ARM EABI kernel and userspace, but > > also need to run one or two OABI binaries (from the gcc 2.95 era) on > > the same kernel which I cannot recompile because they're built with > > closed source libraries only supplied as OABI. > > > > Does that not work at all? > > There are a few ioctl() incompatibilities between the two ABIs, the > main problems are within the ALSA API. Mostly it will work, but there > are a couple of caveats. Right, you can run ARM OABI binaries on an ARM eABI kernel by enabling OABI_COMPAT. However, as Ben notes, there are (more than, IMNSHO ; ) "a couple of caveats". Most of the "easy" ABI compatibility fixups should be handled already via OABI_COMPAT. However, it's practically impossible to fixup all OABI/eABI compatibility issues due to register assignment, parameter alignment and/or packing differences between the two ABIs. You would have to analyze all kernel and driver user interfaces to reassign parameters to registers, align and/or repack data structures, etc.,. In fact, some of the existing fixups include side effects that in some cases can cause userspace code to fail, depending on how it is using I/O parameters, e.g. in some cases, library code may try to validate parameters which are relocated and those tests fail due to reshuffling of parameters. It's a nasty path to go down, quite frankly. I would not recommend trying to support OABI binaries on an eABI kernel using OABI_COMPAT. -- Regards, George > > -- > Ben > > Q: What's a light-year? > A: One-third less calories than a regular year. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-embedded" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
