Hi Piotr, On Mon, 14 Oct 2013 15:49:43 +0200, Piotr Wilczek <p.wilc...@samsung.com> wrote:
> Dear Albert and Måns, > > > -----Original Message----- > > From: Måns Rullgård [mailto:m...@mansr.com] > > Sent: Monday, October 14, 2013 3:05 PM > > To: Albert ARIBAUD > > Cc: Piotr Wilczek; 'Tom Rini'; u-boot@lists.denx.de; 'Kyungmin Park' > > Subject: Re: [U-Boot] [PATCH] disk:efi: avoid unaligned access on efi > > partition > > > > Albert ARIBAUD <albert.u.b...@aribaud.net> writes: > > > > >> > Please do not advise using native unaligned accesses on code that > > >> > is not strictly used by ARMv6+ architectures: the present code, > > for > > >> > instance, might be run on pre-ARMv6 or non-ARM platforms, and > > thus, > > >> > should never assume ability to perform unaligned accesses > > natively. > > >> > > >> I'm advising no such thing. I said two things: > > >> > > >> 1. Declaring a struct with the 'packed' attribute makes gcc > > >> automatically generate correct code for all targets. _IF_ the > > >> selected target supports unaligned ldr/str, these might get > > used. > > >> > > >> 2. If your target is ARMv6 or later _AND_ you enable strict > > alignment > > >> checking in the system control register, you _MUST_ build with > > the > > >> -mno-unaligned-access flag. > > > > > > Then I apologize; I had read "Note that on ARMv6 and later ldr/str > > > support unaligned addresses unless this is explicitly disabled in the > > > system control register" as a suggestion to use that capability. > > > > If building for ARMv6 or later, I do suggest allowing unaligned > > accesses. The moment you add -march=armv6 (or equivalent), you allow > > for a number of things not supported by older versions, so why not > > unaligned memory accesses? > > > > Thank you for your comments, I will follow your advice. I will NAK building part_efi.c with options to allow native unaligned access. I will, OTOH, be ok with explicit unaligned reads/writes. > Best regards > Piotr Wilczek Amicalement, -- Albert. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
