[lwip-users] [lwip] lwip on 8051 with Keil compiler

[DASILVA VINCENTE BIT]

I have ported lwip to 8051 and used uCOS as the HAL for lwip. It compiles to
about 60K. 

I am using the Keil compiler with max optimisation and have found
problems(bugs) with the code generated by the compiler. As I step through
the code there are certain lines of code that are simple variable
assignments. The debugger steps over these lines of code but when I check
the variable in the watch window it is not assigned, If I hardcode the
assignment it works, if I optimise only certain files but not the file
containing that line of code then it works, but fails elsewhere. 

At this point my confidence in the Keil compiler(with max optimisation) is
low, has anyone experienced similar problems with the Keil compiler? Is
there a better compiler than the Keil compiler?

Vicente

-----Original Message-----
From: Andrea Olivotto [mailto:address@hidden
Sent: 03 February 2002 03:05 PM
To: address@hidden
Subject: Re: [lwip] Using lwIP with CS8900A on Atmel 89C51


> If you are willing to sacrifice TCP, you really get the code size down.
TCP
> is nearly 50% of the total code in the core lwIP code. I don't know how
large
> lwIP would be for the 8051 but I would suspect somewhere around 20-30k of
> code for the full stack (including TCP) and perhaps 10k without TCP.
Andrea,
> perhaps you could comment on this?

Yes, of course.

Some month ago I tried with the 0.4.1 version of lwIP: using extensively
XDATA optimization for Keil compiler, I reach about 30kB for the code (about
42kB without optimization). RAM usage obviously depends from lwipopts.h.

Last month I ported 0.5.0, without any optimization for code size: 52kB,
with a very simple web server.
Monday I will tell more about TCP code size.

I guess lwIP is growing too much for 8051 architecture.
Likely it is still usable (I mean it leaves more code space for the
application) with other more recent and efficient 8 bit micros, as Atmel
AVR.

To Adam: is it possible to promote an old release as 0.4.1 or 0.4.2 (lighter
that the latest) to a "stable" and "bug free" release, so we people of
damned 8051 can port it and optimize to the max?
The problem with Keil is that if you begin to optimize the code, you can't
switch easely to the next release.

Are anyone trying to compile lwIP using SDCC? What about code size?

Let us know.


Andrea



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