Hello, due to your hints I've found a solution. The problem was simple: The buffer was not word aligned as the Xscale requires. With char buffer[8192] __attribute__((aligned(4))); things are working. Sometimes you don't see the wood for the trees. So thanks to all for the good hints!
Marcus > -----Ursprüngliche Nachricht----- > Von: "Marcus Tangermann" <[EMAIL PROTECTED]> > Gesendet: 07.11.08 23:52:43 > An: [email protected] > Betreff: Alignment on XScale ARM > Hi, > > we use an XScale 422 (ARM) with a big endian Linux system based on the > buildroot environment. It seems there is an alignment problem we have. I've > tracked down the problem to the following. > 1. The data received via a netlink communication from the kernel is stored > into a buffer buf. The data is correct. > 2. The address of the buffer is converted to a pointer to nlmsghdr: > struct nlmsghdr *h; > h = (struct nlmsghdr*) buf; > printf("IPSECTOOLS: Length %04d\n", h->nlmsg_len); > printf("IPSECTOOLS: Type %02d\n", h->nlmsg_type); > The results of printf are nonsens. The first fields seem to have an offset > of 2 bytes, at the end there also seem to be swapped bytes. > 3. To test what might happen, I've created an own struct > struct aligntest{ > __u32 first; > __u32 int second; > __u32 third; > __u32 fourth; > }; > When you now set a point to a buffer, again the values are wrong: > s1 = (struct aligntest*) buf; > printf("1: %08X\n", s1->first); > printf("2: %08X\n", s1->second); > printf("3: %08X\n", s1->third); > printf("4: %08X\n", s1->fourth); > > It seems, that there is a problem with the unsigned int values. When you add > the attribute "packed" to the definition of struct aligntest ( > __attribute__(__packed__) ), all values are displayed correctly. > So, any hints what the problem can be? > > Regards > Marcus > ____________________________________________________________________ > Psssst! Schon vom neuen WEB.DE MultiMessenger gehört? > Der kann`s mit allen: http://www.produkte.web.de/messenger/?did=3123 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-embedded" in > the body of a message to [EMAIL PROTECTED] > More majordomo info at http://vger.kernel.org/majordomo-info.html > __________________________________________________________________ "Run, Fatboy, Run" sowie "Rails & Ties" kostenlos anschauen! Blockbuster-Gutscheine sichern unter http://www.blockbuster.web.de -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
