[ELDK] enable FPU on my target?

Wolfgang Denk wd at denx.de
Thu May 22 00:51:36 CEST 2008

In message <20080521164045.81245EDBC9 at ws6-1.us4.outblaze.com> you wrote:
>   Does the ELDK add appropriate instructions at compile-time to enable the FPU on an AMCC 440EPx (using ppc_4xxFP)?  I looked at my compiled code with Ida and didn't see an MTMSR instruction, but then again I'm not sure which specific instruction I shou

Application code cannot execute  priviledged  instructions.  The  FPU
gets  enabled by the Linux kernel. You will not see any "enabling" in
application code.

>   Do I need to add the appropriate FPU assembly instructions myself through asm directives in my code?  Is this restored for my process following a context switch?  This seems like I'm having to get very low-level, so surely I'm missing something, right
> ?

Yes, you are missing that your application code  is  running  in  the
context  of an operating system, and the OS (Linux in our case) takes
care of all these nasty little details.

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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