RTEMS on tiny microcontroller

[Benoit Camus]

After doing some tests with samples applications, i've got quite same 
binary size as your.
I will try it on the 512Ko/128ko version of the microcontroler.

I was currently using Lwip but due to lack of some options, i need to 
change. That's why i'm so
interst in FreeBSD stack.

There's on wiki a page about TinyRTEMS which i think is a really 
interesting project.
It says project was up to 25% in 2007, what is the state today ? Is 
there any way to contribute ?

Just a last question, what the preferred way to implement/use static 
allocation ?

Benoit
> Benoit Camus wrote:
>   
>> Hello all,
>>
>> I read a lot of thing about memory usage on mailing list and have to say 
>> i'm a bit in doubt about it.
>>
>> Here is the available memory i have: 256ko Flash /  64ko RAM ( could be 
>> 512/128 but i'd really like to avoid it ).
>> The microcontroller i use is an arm: at91sam7x.
>>
>> The question is what i need ?
>> Of course the kernel itself, ideally with the posix interface and the 
>> Ethernet stack (the FreeBSD one).
>> I guess this last point is the worst. and i don't need all of the stack 
>> just: TCP, UDP layers ( 2-3 connection for each ), Broadcast and 
>> Multicast capability and that's it.
>>     
>
> Here is the memory layout for an application with telnet and FTP services on an
> LPC2478 (ARM Thumb):
>
> Idx Name          Size      VMA       LMA       File off  Algn
>   0 .start        00000120  00000000  00000000  000000d4  2**2
>                   CONTENTS, ALLOC, LOAD, READONLY, CODE
>   1 .vector       000005c0  40000000  40000000  00061bd4  2**0
>                   ALLOC
>   2 .text         00048540  00000120  00000120  000001f4  2**2
>                   CONTENTS, ALLOC, LOAD, CODE
>   3 .rodata       0000b380  00048660  00048660  00048734  2**2
>                   CONTENTS, ALLOC, LOAD, READONLY, DATA
>   4 .data         0000e120  a0400000  000539e0  00053ab4  2**2
>                   CONTENTS, ALLOC, LOAD, DATA
>   5 .bss          00007880  a040e120  a040e120  00061be0  2**5
>                   ALLOC
>
>   
>> Considering all this needs, do you think it will fit in memory ? Is 
>> there any options fine tune the system and  drop down it size ?
>>     
>
> As far as I know the TCP/IP stack is monolithic in RTEMS.  You may have a look
> at http://www.rtems.com/wiki/index.php/Open_Projects#LWIP.
>
>   
>> A last question to help me doing some tests, where could i find a 
>> ready-to-use arm-rtems compiler ?
>>     
>
> http://www.rtems.com/wiki/index.php/RTEMS_Development_Hosts
>
>   
>> Thanks in adavance.
>> B. Camus
>>
>>     
>
>
>   


-- 

Benoît CAMUS
Leroy Automatique Industrielle
Bd du Libre échange - 31650 Saint-Orens
Standard : 05.62.24.05.50
e-mail : benoit.camus at leroy-autom.com