ci20-3.0.8 & u-boot build with binutils 2.24.51+

[Andrey KosteltsevParticipant]

Hi,

A lot of source files in kernel and u-boot during compilation (binutils-2.25, gcc-4.9.2) show the following warning:


{standard input}: Assembler messages:
{standard input}: Warning: .gnu_attribute 4,3 requires `softfloat'


The linux-mips team tracks this issue for a long time and make the patches for kernel. The latest patch can be found at http://patchwork.linux-mips.org/patch/8355/ page.

But in the https://github.com/MIPS/CI20_linux repository this issue is not fixed because the patch http://patchwork.linux-mips.org/patch/8355/ cannot be applied as is because nobody created such patch exactly for kernel version 3.0.8.

Can someone from the Creator Support Team to investigate this issue and develop an appropriate patch for ci20-3.0.8 branch. This will be very helpful for users who want to move to GCC-4.9.2.

Best Regards,
Andrey K.

[ZubairLKParticipant]

Hi Andrey,

We are focusing resources on 3.18.

Do these warnings appear in 3.18 as well?

Regards,
ZubairLK

[Andrey KosteltsevParticipant]

Hi Zubair,

This warnings related only u-boot and ci20-3.0.8. The root cause of this is an issue in pair of binutils-2.25 & gcc 4.8/4.9. GCC team promise fix it at gcc-4.9.4 (gcc-5.0 already fixed). Please find the description at (https://gcc.gnu.org/ml/gcc-bugs/2015-01/msg00830.html) & (https://gcc.gnu.org/ml/gcc-bugs/2015-01/msg00835.html).

Unfortunately the linux-mips.org team doesn’t create kernel patch (http://patchwork.linux-mips.org/patch/8355/) for 3.0.8. They do it for other versions.

I think it is a serious issue which can affect the ci20 kernel. Sourcery CodeBench toolchain contains binutils 2.23.. and gcc-4.8.1.. and I think we have to wait GCC-4.9.4 to be sure that the kernel 3.18.3 work correctly with softfloat on mips32r2 architecture. Related the 3.0.8 kernel I think we need to ask support from linuc-mips team to create correct patch (http://patchwork.linux-mips.org/patch/8355/) exactly for ci20-3.0.8 to be sure that the binutils-2.24.51+ generates correct code in kernel.

Best Regards,
Andrey K

P.S.
Pleade also look at little issue with ci20-3.0.8 headers (https://github.com/MIPS/CI20_linux/issues/69)

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