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John Hind wrote:
Yes, a well designed and useful poster.

One nit-pick. I would prefer to quote "reasonable practical minimum"
requirements rather than the absolute minimum achievable in a pure
benchmarking exercise. On this basis 100K of flash seems low, and in the
embedded context it would be useful to talk about RAM also as these
resources are often very tight on embedded chips.

I would suggest that an important threshold has just recently been crossed
enabling a single chip Lua implementation to be a practical possibility:
512K Flash, 64K RAM (both bytes) with a 32Bit processing core. So far I've
only found one chip in this class, the Atmel AVR32, but other manufacturers
such as Microchip and Texas will no doubt soon catch up. I'm pretty sure in
my own mind that 512K is the practical minimum for a full Lua system with
libraries and space for the application (though a pure runtime virtual
machine might make do with half that). I'm less confident I understand the
RAM requirements though - any comments anyone?

I have a LOT of experience getting Lua to run on an AT91SAM7S256
which is an ARM7TDMI core with 256K FLASH and 64K RAM.

Using gcc, the Lua core (base,string,table,debug) and a run time
library take about 100K of FLASH and there's 58 K of heap available
after all the IO buffers and RAM code is set up.

The biggest problem with small RAM is the fragmentation of the
heap, and that a LOT of RAM is used up for what are essentially
read-only tables that hold functions.

So I can say that Lua in the deeply embedded space is possibly, but
it's difficult to make it dead reliable in the face of memory