On Tue, Apr 22, 2014 at 11:53:25AM -0600, Jason Gunthorpe wrote: > On Tue, Apr 22, 2014 at 06:11:42PM +0100, Russell King - ARM Linux wrote: > > > Put another way, if your platform is part of the multi-platform kernel > > then you are *excluded* from being able to use this... unless you hack > > the Kconfig, and then also provide a constant value for PHYS_OFFSET, > > thereby _tying_ the kernel you built to a _single_ platform. > > That is exactly right. To get a fixed LMA you must commit to a > non-relocatable kernel image. > > Realistically this patch would need to be accompanied by something > that makes ARM_PATCH_PHYS_VIRT optional for multiplatform based on > EXPERT or similar. > > The best usecase seems to be to support ELF tooling for low level > debugging activities, a non-relocatable image isn't a blocker for that > case. Let's not forget that if you want to debug, it's because you've hit a problem in the kernel you're running. To get an ELF image you can debug, you have to turn ARM_PATCH_PHYS_VIRT off, which changes the generated code - which can in itself cause bugs to hide themselves. Unfortunately, those kinds of bugs are not as rare as you might think. > Since the patch is a no-op if LOAD_OFFSET isn't set, is there a > downside I don't see? It leads people into thinking that we support booting an ELF file. We don't. -- FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly improving, and getting towards what was expected from it. -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
