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R: R: [lwip-users] ip_reass
From: |
Ceresoli Luca |
Subject: |
R: R: [lwip-users] ip_reass |
Date: |
Fri, 10 Oct 2008 14:59:16 +0200 |
Ed Sutter wrote:
> 2. pbuf_alloc() setting payload buffers up to be aligned
> based on MEM_ALIGNMENT
"your driver must support it" means you have to:
- set ETH_PAD_SIZE to 2 in lwipopts.h
- allocate 2 extra bytes, eg
pbuf_alloc(PBUF_RAW, your_current_size+ETH_PAD_SIZE, PBUF_RAM)
- take care of those few things that I quite forgot...
Luca
> 3. the increment of the payload pointer by 14 in ethernet_input()
> and...
> 4. the overlay of the "helper" structure in
> ip_reass_chain_frag_into_datagram_and_validate()
>
> will cause the misaligned access. If the option you mention
> fixes it for my
> situation on the BF537, that doesn't resolve it for other systems.
> Right?
> Ed
>
> Ceresoli Luca wrote:
> > Ed Sutter wrote:
> >> I'm running LWIP 1.3.0 on a Blackfin, which is picky about
> >> ...
> >> The ethernet_input() function then sees that it is IP,
> >> increments the payload
> >> pointer by 14 (size of ethernet header) and passes the pbufs
> >> to ip_input().
> >> Note that at this point, the payload pointer is no longer
> >> aligned on a 4-byte
> >> boundary because the original 4-byte-aligned payload pointer
> >> is incremented
> >> by 14.
> >
> > Which Blackfin are you using?
> > Tha Ethernet MAC of Blackfin 536/7 can optionally add two
> dummy bytes in front of incoming frames (setting bit RXDWA in
> the EMAC_SYSCTL register). This makes all TCP/IP headers
> 4-byte aligned.
> >
> > Of course your driver must support it.
> >
> > Luca
> >
> >
> > _______________________________________________
> > lwip-users mailing list
> > address@hidden
> > http://lists.nongnu.org/mailman/listinfo/lwip-users
> >
>
>
> _______________________________________________
> lwip-users mailing list
> address@hidden
> http://lists.nongnu.org/mailman/listinfo/lwip-users
>
- Re: [lwip-users] ip_reass, (continued)
- Re: [lwip-users] ip_reass, Ed Sutter, 2008/10/09
- R: [lwip-users] ip_reass, Ceresoli Luca, 2008/10/10
- Re: R: [lwip-users] ip_reass, Ed Sutter, 2008/10/10
- Re: R: [lwip-users] ip_reass, Kieran Mansley, 2008/10/10
- Re: R: [lwip-users] ip_reass, address@hidden, 2008/10/10
- Re: R: [lwip-users] ip_reass, Kieran Mansley, 2008/10/10
- Re: R: [lwip-users] ip_reass, Ed Sutter, 2008/10/11
- Re: R: [lwip-users] ip_reass, Simon Goldschmidt, 2008/10/11
- Re: R: [lwip-users] ip_reass, Ed Sutter, 2008/10/11
- Re: [lwip-users] ip_reass, address@hidden, 2008/10/17
- R: R: [lwip-users] ip_reass,
Ceresoli Luca <=
RE: [lwip-users] ip_reass, Taranowski, Thomas (SWCOE), 2008/10/09
Re: [lwip-users] ip_reass, urs . gerber, 2008/10/08
Re: Re: [lwip-users] ip_reass, urs . gerber, 2008/10/09