On Wed, Jan 19, 2011 at 10:29 PM, Kevin Hilman <khilman@xxxxxx> wrote: > Dave Martin <dave.martin@xxxxxxxxxx> writes: > >> In low-level board support code, there is sometimes a need to >> copy a function body to another location at run-time. >> >> A straightforward call to memcpy doesn't work in Thumb-2, >> because bit 0 of external Thumb function symbols is set to 1, >> indicating that the function is Thumb. Without corrective >> measures, this will cause an off-by-one copy, and the copy >> may be called using the wrong instruction set. >> >> This patch adds an fncpy() macro to help with such copies. >> >> Particular care is needed, because C doesn't guarantee any >> defined behaviour when casting a function pointer to any other >> type. This has been observed to lead to strange optimisation >> side-effects when doing the arithmetic which is required in >> order to copy/move function bodies correctly in Thumb-2. >> >> Thanks to Russell King and Nicolas Pitre for their input >> on this patch. >> >> Signed-off-by: Dave Martin <dave.martin@xxxxxxxxxx> >> Tested-by: Jean Pihet <j-pihet@xxxxxx> > > Tested-by: Kevin Hilman <khilman@xxxxxx> > > along with Jean's OMAP patch on: > > OMAP2420/n810: including basic suspend/resume test. > > OMAP16xx/OSK: boot test only. > > Kevin > Thanks ---Dave -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
