Gigabit Ethernet Interface (via Marvell 88E1111) with Cyclone IVE FPGA

Hi,

The ethernet transmit frame after changing the original code to ether type IP is:

unsigned char tx_frame[1024] = {

0x00,0x00, // for 32-bit alignment

0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, // destination address (broadcast)

0x01,0x60,0x6E,0x11,0x02,0x0F, // source address

0x08,0x00, // length or type of the payload data

'\0' // payload data (ended with termination character)

};

According to some internet source:

// The packet length# define PCKT_LEN 1024

// The IP header's structure

struct ipheader {

unsigned char iph_ihl:5, iph_ver:4;

unsigned char iph_tos;

unsigned short int iph_len;

unsigned short int iph_ident;

unsigned char iph_flag;

unsigned short int iph_offset;

unsigned char iph_ttl;

unsigned char iph_protocol;

unsigned short int iph_chksum;

unsigned int iph_sourceip;

unsigned int iph_destip;

};

// UDP header's structure

struct udpheader {

unsigned short int udph_srcport;

unsigned short int udph_destport;

unsigned short int udph_len;

unsigned short int udph_chksum;

};

// The checksum

unsigned short csum(unsigned short *buf, int nwords)

{ //

unsigned long sum;

for(sum=0; nwords>0; nwords--)

sum += *buf++;

sum = (sum >> 16) + (sum &0xffff);

sum += (sum >> 16);

return (unsigned short)(~sum);

}

char buffer[PCKT_LEN];

// Our own headers' structures

struct ipheader *ip;

struct udpheader *udp;

// Fabricate the IP header or we can use the

// standard header structures but assign our own values.

ip->iph_ihl = 5;

ip->iph_ver = 4;

ip->iph_tos = 16; // Low delay

ip->iph_len = sizeof(struct ipheader) + sizeof(struct udpheader);

//ip->iph_ident = htons(54321);

ip->iph_ident = 54321;

ip->iph_ttl = 64; // hops

ip->iph_protocol = 17; // UDP

// Source IP address, can use spoofed address here!!!

ip->iph_sourceip = 0xa074;

// The destination IP address

ip->iph_destip = 0xa073;

// Fabricate the UDP header. Source port number, redundant

udp->udph_srcport = 0x80;

// Destination port number

udp->udph_destport = 0x70;

udp->udph_len = sizeof(struct udpheader);

// Calculate the checksum for integrity

ip->iph_chksum = csum((unsigned short *)buffer, sizeof(struct ipheader) + sizeof(struct udpheader));

memcpy(buffer,&ip, sizeof(ip));

memcpy((buffer+ sizeof(ip)),&udp, sizeof(udp));

Now I am wondering how I can add this IP and UDP header to the raw data. I mean there is no any socket number or something like that. So where I have to map the variable buffer now?

Is it to change some parameters here(below) in original code? If yes, how? If not what is alternative?

// Create transmit sgdma descriptor

alt_avalon_sgdma_construct_mem_to_stream_desc( &tx_descriptor, &tx_descriptor_end, tx_frame, 1480, 0, 1, 1, 0 );

// Set up non-blocking transfer of sgdma transmit descriptor

alt_avalon_sgdma_do_async_transfer( sgdma_tx_dev, &tx_descriptor );

// Wait until transmit descriptor transfer is complete

while (alt_avalon_sgdma_check_descriptor_status(&tx_descriptor) != 0)

;

}

return 0;

}