[PATCH] arm: omap2: enable smc instruction for sleep34xx

["Anderö, Oskar"]

> > > Ping!
> > >
> > > Anyone else that gets bitten by the following when compiling
> > omap2plus_defconfig with gcc 4.5:
> > > arch/arm/mach-omap2/sleep34xx.S:150: Error: selected processor does
> not
> > support ARM mode `smc #1'
> > >
> > > -Oskar
> > >
> >
> > I can report that I get the exact same compile error as this.
> > OP patch worked beautifully.
> >
> > -Alex
> 
> Can you check what options are being passed to the compiler
> and the assembler, and check for .arch / .arch_extension directives
> in the assembler input?
> 
> i.e.,
> 
> make V=1 CFLAGS_KERNEL='-v -save-temps' arch/arm/mach-omap2/sleep34xx.o
> 
> ...and look at the output and the generated sleep34xx.s
> 
> Maybe the options being passed to the compiler/assembler are wrong
> somewhere along the line.
Yes, the "+sec" extension of armv7-a (i.e. -march=armv7-a+sec) is missing and hence the smc instruction can't be used. This is what my patch fixes. I guess earlier versions of binutils silently ignored this.

It's not visible in my patch, but plus_sec is declared as:
plus_sec := $(call as-instr,.arch_extension sec,+sec)

The following patch added the same extension for some of the other files, but I guess sleep34xx.S was missed or maybe added later:
commit fe297dde5ae8f8bf67d3a87759289a99b48ecb2c
Author: John Rigby <john.rigby at linaro.org>
Date:   Wed Dec 1 05:57:51 2010 +0000

    OMAP4: enable smc instruction in new assembler versions
    
    New assemblers need -march=armv7-a+sec on command line or
    .arch_extension sec inline to enable use of the smc instruction.
<snip>

-Oskar