[En-Nut-Discussion] Ethernut Microchip PIC port

[Henrik Maier]

Ake Hedman wrote:

> is there a port (or something on the way) of EtherNut to the Microchip 
> PIC platform.

 From my point of view the PIC18 architecture is too limited to be used 
for an advanced OS as Nut/OS is. The PIC18 supports only up to 4 KB of 
RAM and this RAM can't even be used continuously, it has to be used in 
banks of a maximum of 256 bytes (16 banks max.), at least when you 
allocate statically. The other limitation is the program counter stack. 
PC stack cannot be allocated in RAM but must be in a special stack space 
of only 32 stack locations. Nut/OS is using dynamic memory to allocate 
stack space for the threads it's running and is using stack plentifully 
and deep. With interrupts and context switching I am sure a 32 location 
deep stack will overrun quickly.

Cheers,

Henrik

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