From mboxrd@z Thu Jan 1 00:00:00 1970 From: jgunthorpe@obsidianresearch.com (Jason Gunthorpe) Date: Fri, 13 Dec 2013 17:31:15 -0700 Subject: [PATCH 5/5] arm64: Add LOAD_OFFSET symbol for linker scripts In-Reply-To: <1386980430.1002.96.camel@smoke> References: <92660d1b81279aa6784a33eff2f102e78d883931.1386879684.git.geoff@infradead.org> <20131213164517.GM19177@mudshark.cambridge.arm.com> <1386980430.1002.96.camel@smoke> Message-ID: <20131214003115.GI12904@obsidianresearch.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Dec 13, 2013 at 04:20:30PM -0800, Geoff Levand wrote: > > Can you be more specific about why we need this please? We don't seem to use > > this on ARM, and I can't really think of a sensible value to define it as, > > either. PAGE_OFFSET is a virtual address, which doesn't make much sense to > > me, but perhaps I'm missing something. > > As I mentioned before, LOAD_OFFSET defaults to zero if it is not defined by the > arch, so our arm64 vmlinux files currently have their paddr's equal to their > vaddr's, so something like 0xffffffc000080000. FWIW, I posted a similar patch for ARM32 last year: https://lkml.org/lkml/2012/9/30/145 We are using it here to convey to desired load address to the boot loader. My patch makes LOAD_OFFSET equal to PLAT_PHYS_OFFSET for non-relocatable kernels, 0 otherwise. If ARM64 takes Geoffs changes I can resend my patch for ARM32. Regards, Jason