On Fri, Jan 11, 2019 at 9:43 PM Tom Rini <tr...@konsulko.com> wrote: > > On Mon, Jan 07, 2019 at 02:43:05PM +0530, Lokesh Vutla wrote: > > > Hi All, > > I am trying to enable CONFIG_USE_ARCH_MEMSET/MEMCPY on arm64 > > platforms and > > realized that there is no arm64 specific memcpy available in u-boot. So I > > tried porting arm64 specific memcpy from kernel[1]. Memcpy stopped working > > after that and observed that if destination address is unaligned then system > > hangs. > > > > After doing a bit more research, understood that unaligned access to device > > or strongly ordered memories will fail. And the memory system (even normal > > RAM) behaves like strongly ordered memory when the MMU is disabled[2]. In > > u-boot MMU is enabled very late after relocation and SPL doesn't enable MMU > > at all. > > > > Before I proceed any further wanted to hear from others if anyone have > > already tried and have any working solution. If not should we update the > > kernel memcpy to use unaligned destination address and use it in u-boot? > > > > [1] > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/lib/memcpy.S > > [2] > > https://community.arm.com/processors/f/discussions/7557/when-and-where-will-the-ldp-instruction-trigger-an-exception > > I suspect we should, yes. Adding in some custodians of other arm64 > platforms for comment.
Right now we still use it from lib/string.c we don't enable ARCH_MEMCPY for arm64, indeed there is no code for doing that, if I'm not wrong. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
