[lwip-users] alignment problems

[Bartlomiej Wicher]

Hello

I am a newbie in LWIP and it's my first post to this list. I'm trying to  
use LWIP with Freescale DSP568366. I have some problems with value of  
MEM_ALIGNMENT. Normally microprocessor are 8-bit addressable,  but the  
DSP568366 is word-addressable (16-bits). It means that each address of  
memory stores dwo bytes. Moreover:

+ Size of char is 1 byte - it is stored in one word (one address used)
+ Size of int is 2 bytes - it is also stored in one word
+ Size of long is 4 bytes - it is stored in two words (two addresses  
involved)
+ An array of chars is "packed" automatically by the microcontroller, so  
that 2 consecutive chars are stored in one word.

What value of MEM_ALIGNMENT should I use? Can I use LWIP memory functinos  
(mem_malloc() etc) without any changes in their original source code, or  
should I use the stdio mem functions (malloc() etc)? Finally - do I have  
to make any changes in the original LWIP source code due to my my  
architecture?

Thanks in advance for help

--
Bartlomiej Wicher
University of Southern Denmark
Odense, Denmark