[U-Boot] Testing report for i.MX51 using Linaro/Ubuntu gcc 4.6.3 (from Precise repositories), libgcc, etc.

[Rob Herring]

On 08/02/2012 12:49 PM, Matt Sealey wrote:
> Marek Vasut insists I report this to the list, so here goes;
> 
> Compiling a U-Boot for i.MX51 here (for the Efika MX) basically
> doesn't operate well. Among other things, we got data aborts in
> several places, most annoyingly sometime after boot_relocate_fdt. This
> was using a 64-bit Ubuntu Precise Pangolin (12.04) installation, the
> standard "arm-linux-gnueabi-gcc-4.6" (4.6.3-1ubuntu5) compiler and
> other toolchain components (no modifications made).
> 
> Using USE_PRIVATE_LIBGCC=yes solved the issues, as did changing to the
> gcc 4.4.7 (4.4.7-1ubuntu2) and using either private libgcc or the one
> provided by the toolchain.
> 
> This is not the first problem we've ever had with the Linaro gcc
> toolchain, especially not with 4.6. So far, reverting to building
> using gcc 4.4.7 has solved all the problems, and we're using
> USE_PRIVATE_LIBGCC by default now anyway because I don't see the point
> in using the one provided with the toolchain if it is such a huge
> unknown and U-Boot provides a compatible feature anyway.
> 
> I'm not sure what anyone on the list is going to make of this or if it
> influences some design decisions anywhere else in U-Boot, just that I
> was nagged incessantly to "report my findings" - we all knew the
> Linaro compiler generally sucks already, though, right?

Do you have unaligned-accesses disabled? This version of the compiler
and gcc 4.7 or later will generate unaligned accesses which u-boot does
not enable the h/w for. There was a patch recently to address this.

Rob