On Mon, Jan 11, 2010 at 04:26:30PM +0000, Catalin Marinas wrote: > On Mon, 2010-01-11 at 15:23 +0000, Russell King - ARM Linux wrote: > > On Mon, Jan 11, 2010 at 08:48:37PM +0530, Shilimkar, Santosh wrote: > > > > Do you need to specify "r12" as well? What about "cc", are they > > > > preserved by the secure monitor? > > > > > > r12 and reset of the registers are preserved. Lr needs to be saved but > > > because of function call, the compiler saves/restores it. > > > > That's not guaranteed; the compiler can re-use lr for its own purposes > > within a function. You need to add lr to the list of clobbered registers. > > Do we need to specify "r12" in the list of clobbered registers as the > inline asm explicitly modifies it? Or the compiler doesn't touch it.
Yes - again, the compiler should be told about everything that potentially could change in an asm statement. The compiler could decide to inline debug_writel, and use things like r12 and lr to store temporary values within the parent function across these calls. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
