How to enable NEON instruction Support in the kernel

Hi,
I get the illegal instruction error at runtime upon usage of
components containing the Neon Instructions. I hope that if I know how
to enable the NEON instruction Support in the kernel, my problem will
be resolved!
Regards,
Sanjeev Kumar Verma

Op 22 jul 2009, om 16:30 heeft Sanjeev Kumar Verma het volgende geschreven:

Hi,
I get the illegal instruction error at runtime upon usage of
components containing the Neon Instructions. I hope that if I know how
to enable the NEON instruction Support in the kernel, my problem will
be resolved!

zcat /proc/config.gz | grep NEON
CONFIG_NEON=y

It's enabled over here.

regards,

Koen

hi,
I did not get you. What should I do to enable the Neon Instruction
support?
I am using the Android port for beagle board (which includes the
kernel source also )downloaded from
http://labs.embinux.org/index.php/Android_For_OMAP3_with_Gstreamer_Integration.

Regards,
Sanjeev Kumar Verma

Rupesh,
I got the way to Enable the neon support in the kernel in two steps -
I run these command on the kernel make file
1. make omap3_beagle_android_defconfig
2. make menuconfig
For enabling neon,
Floating point emulation ---> select NEON Advanced SIMD Extension
support and FastFPE math emulation (EXPERIMENTAL)

then exit

and yes while exiting

My Qs are -
Q1. if I build the Entire Android again, will it overwrite the neon
enable settings which I have done?
Q2 Which file among omap3_beagle_android_defconfig and
dss_omap3_beagle_defconfig has to be selected in the first command?
Q3 How to build the kernel alone?

Regards,
Sanjeev Kumar Verma

Op 22 jul 2009, om 18:19 heeft Sanjeev Kumar Verma het volgende geschreven:

Rupesh,
I got the way to Enable the neon support in the kernel in two steps -
I run these command on the kernel make file
1. make omap3_beagle_android_defconfig
2. make menuconfig
For enabling neon,
Floating point emulation ---> select NEON Advanced SIMD Extension
support and FastFPE math emulation (EXPERIMENTAL)

bzzzzt, wrong. The KConfig symbol you actually need was in my first reply.

To build the kernel seperately if I type make for kernel I get "make:
arm-linux-gcc: Command not found
"
If I include another another toochain for this command I get the
error:-
error: #error Your version of gcc miscompiles the __weak directive
make[1]: *** [kernel/bounds.s] Error 1
make: *** [prepare0] Error 2

I don't know what to do?
Regards,
Sanjeev Kumar Verma

Keon,
I did not understand. Please specify the steps clearly what to do to
enable the Neon support in my kernel.
Regards,
Sanjeev Kumar Verma

I saw the same "illegal instruction" message on my console when
working with NEON until I reflashed the nand with the newest version
of the kernel.

In the linux omap kernel [assuming you have already done "make ARCH=arm omap3_beagle_defconfig]
make ARCH=arm menuconfig

Under the “Floating point emulation” Select “Advanced SIMD (NEON) Extension support”.
Save the configuration and exit.

Check in the .config file whether you have “CONFIG_NEON=y”

  • Jesslyn