Re: lua - running bytecode from an external ram space

[Rob Kendrick <rjek@...>]

On Wed, Jul 13, 2011 at 09:57:56PM +0200, imo wrote:
> > running  Lua on a microcontroller _that_ small
> > with so little memory
> > will be very, very slow.
> James, we talking 80/120MHz clocked 32bit microcontrollers with
> flash >128kB and ram >16kB. Have a look at pic32mx5/6/7, stm32f1xx,
> stm32f2xx, .. They are fast, indeed.. They can run Lua easily, the
> only issue is the internal ram size.

We like the STM32 at work.  Remember that some models have a local
memory bus that you can just slap RAM on and address directly.

I'm not sure we've ever looked into running Lua /on/ devices, but we
often use Lua in device drivers and such.  We're currently using models
with 20kB of RAM: I'm not sure it's wise to use any code that calls
malloc() on such a device.  If we wanted to do this, we'd use an ARM9
MCU, as these often have a lot more RAM and an MMU that you can use for
paging.  Often not a great deal more expensive, either.  Look at NXP's
LPC range: available up to 256kB of RAM and a local memory bus should
you need more.

B.