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Hi all,
Has any body tried opening up the Ethernet packet that was received by the WarP and checked out the mac address or the IP address information at the WarP level. I tried to print the
Macframe *packet
for(.....
packet->data[i]
....
but the data that was printed and the data that was received are entirely different, is it because i am accesing a different memory location?
how do i then get to open ethernet packet in the WarP platform level ?
-Ragha
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The Macframe associated with the received wireless packet does not have the Ethernet payload in it; it is only the wireless header plus a "isNew" flag that is used by some of our other MAC layers.
If you want to user code to have access to the underlying payload, you can use the "warpphy_getBuffAddr" function like it is used here
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Hi Chris,
Sorry for not giving details about the hardware/software version we are using, we are currently using
OFDM Reference Design v04 (60MB .zip file) - For kits without a 40MHz converter reference clock.
this version
and in the warpmac.h the structure is as below
typedef struct {
volatile unsigned char pktRev;
volatile unsigned char pktType;
volatile unsigned char destAddr[6];
volatile unsigned char srcAddr[6];
volatile unsigned char currReSend;
volatile unsigned int length;
//volatile unsigned char *data;
volatile Xuint32 *data __attribute__ ((aligned (8)));
volatile unsigned int chkSum;
volatile unsigned char isNew;
} Macframe;
In this case what should we do to access the ethernet payload with 0.4 version. It will take some time for us to have the 1.0 compatible warp boards.
-Ragha
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The data field is definitely a pointer to the packet payload; on line 133 of warpmac.c, you can see the call:
RxStatus = XEmac_FifoRecv(EmacPtr, txPacket->data, &length);
That call initiates the DMA transfer of an Ethernet packet from the EMAC to the buffer pointed to by txPacket->data. The analogous call for received wireless packets is on line 1054:
mimo_ofdmRx_copyPayload(packet->data, (size_t)(16 + packet->length));
This one executes a memcpy from the PHY's packet buffer to the intermediate buffer pointed to by packet->data.
Are you sure you're using the right calls for handling the pointers? I always get tripped up with struct pointers which contain fields which are pointers themselves.
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Hi Murphpo,
You are right, i actually did not make a call to this function
mimo_ofdmRx_copyPayload(packet->data, (size_t)(16 + packet->length));
and was blindly accessing the memory which was why i got wrong results.
thanks for the correction. (Now am getting the hang of WARP thanks to this forum)
-Ragha
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