I have to use Neon co-processor of Ti Sitara am335x processor. To enable neon, I have to enable the 30th bit of FPEXC(floating point exceptional register). For that I need to get into the privilaged/system mode.
Some of them suggested to attain this by sending interrupts. How to do that for cortex A8? Could anyone explain me?
Thanks.
You can use interrupts or svc to get into privileged mode, but then your OS code will be running and you would have no control. How do you then propose to enable neon by accessing fpexc?
Your best bet will be recompile your OS with floating point / neon enabled. This will enable the vfp/neon unit at bootup. Also when vfp/neon is enabled ,the task switcher will need to save restore the fpu registers along with general purpose registers.