Hi Holger,

On Wed, Apr 22, 2015 at 11:52 AM, Holger Freyther <holger@freyther.de> wrote:

> On 22 Apr 2015, at 14:42, Eliot Miranda <eliot.miranda@gmail.com> wrote:

Hi,

>�� thanks to hard work by Tim Rowledge and Lars Wasserman we now have a functional JIT for the ARM in the simulator.�� We're still probably some weeks away from a functional ARM JIT VM; issues like instruction cache flushing on real hardware can be tricky to solve.�� But we're at least ready to start trying to compile the JIT VM for ARM.�� Doug, see that I added a build directory for build.linux32ARM/squeak.cog.spur.�� Hopefully a fast VM for Raspberry Pi and Android is only a few weeks away.

tricky in which sense? The Linux kernel offers a syscall (cacheflush) where one
provides the start page and end page and GCC provides a builtin function for this
as well (__clear_cache).

��that's good news.�� It wasn't always that easy.�� When we got the ARM JIT working for VisualWorks we had to use hand-rolled code to flush the cache as linux didn't provide a reliable function at that time.�� So perhaps we're closer than we think.�� But it's always wise to lengthen time estimates, not shorten them :-)

holger

cache flush:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/kernel/traps.c?id=9ea18f8cab5f1c36cdd0f09717e35ceb48c36a87#n611

best,

Eliot