Albert ARIBAUD <albert.arib...@free.fr> writes: > Le 18/02/2011 16:16, Raghuveer Murthy a écrit : >> U-boot built for MeeGo on PandaBoard, with compiler option >> -mfloat-abi=hard, caused a build break. Please refer to the bug id: >> >> http://bugs.meego.com/show_bug.cgi?id=13140 > > Is this the official U-Boot? Why is it still at 2010.09 ? > >> Removing the -msoft-float options in the config.mk files, allowed it >> to be built for both armv7hl and armv7el compilers on MeeGo >> >> Please refer to the below link for more details: >> http://wiki.meego.com/SDK/Toolchains/ToolchainChangeProposal >> >> Signed-off-by: Raghuveer Murthy<raghuveer.mur...@ti.com> > > I would like to know which board of mainline U-boot is affected by the > issue and how I can reproduce it on u-boot[-arm]/master.
I saw this for a while when building for Beagle. It no longer occurs with mainline u-boot. I can't say which commit fixed it. > However, I can already tell that this 'bug' can only occur upon a mix of > object files compiled with -msoft-float and -mhard-float; which means > some files were compiled with -mhard-float; and this should not happen > at all, since U-Boot should not use any floats at all, so: The problem was that something from libgcc got pulled in, probably an integer division or similar. > - either some files in the case reported were compiled voluntarily with > hard-float, and this is not a generally supported use case of U-Boot; > > - or they were compiled without any float option and the toolchain > defaulted to hard-float, which may be a meego but is no reason in itself > for U-Boot to adapt to it. In my case, it was the latter cause. > My feeling at the moment is that U-Boot should keep -msoft-float, to be > sure that any float code present in the code base, if it has to be, will > run regardless of hw floating point capabilities, because U-Boot > binaries should make the least possible assumptions on the hardware they > are running on. > > Now, CPUs/SoCs/boards that know they have a floating point unit may > justly want to replace -msoft-float with -mhard-float everywhere > throughout U-Boot; I would welcome a patch that allows U-Boot to default > to soft float while allowing CPUs/SoCs/boards to override it for hard float. > > In no case, however, should -msoft-float be *removed*: that would make > float support in U-Boot implicit and dependent on the toolchain in use, > and I think U-Boot float support should always be explicit and not > depend on the toolchain. There is no reason for supporting hardware floating-point in u-boot. If floating-point is used at all, and I can't think of a place where it is, it is not relevant to performance. The added complexity of supporting a hardware FPU is not worth it, in my opinion. -- Måns Rullgård m...@mansr.com _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot