Re: [lwip-users] Alignment in pbufs

[Jonathan Larmour]

Matthias Weisser wrote:
> Hi
>
> I am making progress in bringing up lwIP on my board. Can I assume that
> pbufs are always completely filled? So, for example if a I have a packet
> length of lets, say 131 bytes the first pbuf in the chain contains 128
> bytes and the second one contains 3 byte? That would make my life a bit
> easier as the ethernet controller always awaits 32 bit at a time.

On transmission, this would not be guaranteed. lwIP pbufs usually reserve 
some space on the front of pbufs for headers, which may or may not get 
completely used.

On reception, whether this is true or not depends on the ethernet driver 
implementation and that's up to you!

Jifl
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