RE: [lwip-users] lwip + sam7x = udef exception

[B B]

Hi Kieran,
 
This is the information i have gathered, when the undef exception occurs:
 
Exception data:
MC_ASR:
MC_ASR =  0x04040202
 
MISADD: Misaligned Address Abort Status
1: The last aborted access was due to an address misalignment.
 
ABTSZ: Abort Size Status
Word
 
ABTTYP: Abort Type Status
Data Read
 
MST_ARM: ARM Abort Source
1: The last aborted access was due to the ARM.
 
MC_AASR:
ABTADD: Abort Address
This field contains the address of the last aborted access.
 
MC_AASR =  0x0011117e
 
code line information:
 
offending instruction:
adds r4, r3, #0x0
 
offending c statement:
tcphdr = (struct tcp_hdr *)((u8_t *)p->payload + IPH_HL(iphdr) * 4);
 
Register data:
R3 = 0x0020135c
R4 = 0x0020b1fa
CPSR = 0x0000009b
SPSR_UND = 0x0000001f

Packetdata:
tcphdr @0x0020b1fa
_hdrlen_rsvd_flags  0x0270
 
iphdr @0x0020b1e6
_v_hl_tos   0x0045
_len   0x3000
_id   0x8651
_offset   0x0040
_ttl_proto  0x0680
_chksum   0x43fd
 
pbuf_pool @0x0020b7b4
tot_len 0x05dc
len 0x05dc
flags 2
ref 0
payload 0x03030201
 
pbuf_pool->next @0x0020abdc
tot_len 0x05dc
len 0x05dc
flags 2
ref 0
payload 0x03030201
 
pbuf_pool->next->next @0x0020a5f0
tot_len 0x05dc
len 0x05dc
flags 2
ref 0
payload 0x03030201
 
pbuf_pool->next->next->next @0x00000000

If you want some other data, than provided in this mail, please tell
me what variable values you want.
 
regards,
Martin

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> Subject: Re: [lwip-users] lwip + sam7x = udef exception
> From: address@hidden
> To: address@hidden
> Date: Tue, 13 Feb 2007 13:56:41 +0000
> 
> On Tue, 2007-02-13 at 13:35 +0000, B B wrote:
> > Hi all,
> > 
> > I am currently looking into a problem, where an undef exception
> > occurs. The time in which the exception occurs,
> > seem to be random from 5 minutes to 1 hour. And i am writing here
> > because this might be a common error/bug in the code.
> 
> Is this based on a port that someone else wrote, or are you porting lwIP
> to your hardware yourself? 
> 
> It is unusual for a memory alignment problem to be so sporadic. Can you
> find out more about the values of the addresses that are trying to be
> accessed? Also of interest would be how these addresses relate to the
> packet that is being processed. i.e. what are the addresses of the
> start of the pbuf, and where do things like the ethernet header begin
> and end.
> 
> Kieran
> 
> 
> 
> _______________________________________________
> lwip-users mailing list
> address@hidden
> http://lists.nongnu.org/mailman/listinfo/lwip-users

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