Questions about FPU and NEON on Cortex-A9 with armv7 instructions!

Martin Guy martinwguy at
Wed Jul 28 04:57:43 EDT 2010

On 7/28/10, David Yang <david.yangshuai at> wrote:
>        Because I need use the NEON on Cortex-A9, so I want to add the
>  parameter : -mfpu=neon -mfloat-abi=softfp to the KBUILD_CFLAGS and
>  KBUILD_AFLAGS in the Makefile of the top dir like below:

Hi David
   Linux never uses the FPU internally, in fact it doesn't use
floating point at all. Linux's task with the FPU is only to initialize
it so that user-space applications can use it, and to save/restore FP
register contents when two processes are both using it.
   In the kernel itself only integer math is used.



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