On Fri, Jun 08, 2012 at 03:43:00PM +1000, g...@snapgear.com wrote: > From: Greg Ungerer <g...@uclinux.org> > > All current ColdFire CPUs are able to support unaligned memory accesses. > So remove the CONFIG_CPU_HAS_NO_UNALIGNED option selection for ColdFire. > > It seems that the current restriction was inherrited from the early non-MMU > support for the basic 68000 proecssors - which do not support unaligned > accesses.
It seems that the first ColdFires needed the restriction : I read in the "MCF5200 ColdFire Family Programmer’s Reference Manual" : The ColdFire processor default configuration supports word- and longword-sized operand references on 0-modulo-2 and 0-modulo-4 addresses, respectively. All other references are defined as misaligned accesses. Any attempt to access a misaligned operand generates an address-error exception, unless the optional hardware module for handling misalignment is present. This misalignment module converts any misaligned operand references into a series of aligned bus cycles to access the data. The existence of the misalignment module is implementation-dependent and is documented in the appropriate ColdFire user’s manual. Philippe _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
