void VgaScreen::clear()
{
alt_u16 x_col,y_col;
for(y_col=0;y_col < 480; y_col++)
for(x_col=0;x_col< 640; x_col++)
Vga_Clr_Pixel(base,x_col,y_col);
}
//**********************************************************************************************//
//******************************* Receive Packet Handling *********************************//
//**********************************************************************************************//
static void ethernet_interrupt_handler() {
unsigned int receive_status;
int i;
int j;
int k;
int termination;
int byte14;
int byte15;
int byte16;
int byte17;
int byte18;
int byte19;
int byte20;
int byte21;
int byte22;
int byte23;
int byte24;
int byte25;
int byte26;
int byte27;
int byte28;
int byte29;
int byte30;
int byte31;
int byte32;
int byte33;
int ip_header0;
int ip_header1;
int ip_header2;
int ip_header3;
int ip_header4;
int ip_header5;
int ip_header6;
int ip_header7;
int ip_header8;
int ip_header9;
int long crc_twos;
int crc_carry;
int crc_ones;
unsigned int long checksum;
alt_u32 checksum_32;
receive_status = ReceivePacket(receive_buffer, &receive_buffer_length);
if (receive_status == DMFE_SUCCESS) {
#if 1
printf("\n\nReceive Packet Length = %d", receive_buffer_length);
for (i = 411; i < 435; i++)
{
for (j = 0; j < 640; j++)
{
Vga_Clr_Pixel(VGA_0_BASE, j, i);
}
}
for(i=0;i<receive_buffer_length;i++) {
if (i%8==0) printf("\n");
printf("0x%.2X,", receive_buffer[i]);
}
printf("\n");
#endif
if (receive_buffer_length >= 14) {
// A real Ethernet packet
if (receive_buffer[12] == 8 && receive_buffer[13] == 0 &&
receive_buffer_length >= 34) {
// An IP packet
if (receive_buffer[23] == 0x11) {
// A UDP packet
if (receive_buffer_length >= UDP_PACKET_PAYLOAD_OFFSET) {
//**********************************************************************************************//
//***************************** Incoming Checksum Validation ******************************//
//**********************************************************************************************//
byte14 = receive_buffer[14] << 8;
byte15 = receive_buffer[15];
byte16 = receive_buffer[16] << 8;
byte17 = receive_buffer[17];
byte18 = receive_buffer[18] << 8;
byte19 = receive_buffer[19];
byte20 = receive_buffer[20] << 8;
byte21 = receive_buffer[21];
byte22 = receive_buffer[22] << 8;
byte23 = receive_buffer[23];
byte24 = receive_buffer[24] << 8;
byte25 = receive_buffer[25];
byte26 = receive_buffer[26] << 8;
byte27 = receive_buffer[27];
byte28 = receive_buffer[28] << 8;
byte29 = receive_buffer[29];
byte30 = receive_buffer[30] << 8;
byte31 = receive_buffer[31];
byte32 = receive_buffer[32] << 8;
byte33 = receive_buffer[33];
ip_header0 = byte14 + byte15;
ip_header1 = byte16 + byte17;
ip_header2 = byte18 + byte19;
ip_header3 = byte20 + byte21;
ip_header4 = byte22 + byte23;
ip_header5 = byte24 + byte25;
ip_header6 = byte26 + byte27;
ip_header7 = byte28 + byte29;
ip_header8 = byte30 + byte31;
ip_header9 = byte32 + byte33;
crc_twos = ip_header0+ip_header1+ip_header2+ip_header3+ip_header4+ip_header5+ip_header6+ip_header7+ip_header8+ip_header9;
printf("\n %hx twos: ", crc_twos);
crc_carry = crc_twos >> 16;
printf("\n %hx carry: ", crc_carry);
crc_ones = crc_twos + crc_carry;
printf("\n ones: %hx", crc_ones);
checksum = (crc_ones ^ 0xFFFF) & 0xFFFF; // invert bits
printf("\n %hx checksum: ", checksum);
//**********************************************************************************************//
//******************************* Display Received Message ********************************//
//**********************************************************************************************//
if (!checksum)
{
put_vga_string("Message received.", 0, 26);
printf("Received: %s\n",receive_buffer + UDP_PACKET_PAYLOAD_OFFSET);
if (current_line < 25 && receive_buffer_length < 79)
{
for (i = UDP_PACKET_PAYLOAD_OFFSET; receive_buffer[i] != 0; i++)
put_vga_char(receive_buffer[i], i-UDP_PACKET_PAYLOAD_OFFSET, current_line);
current_line++;
}
else if (current_line < 24 && receive_buffer_length > 78)
{
for (i = UDP_PACKET_PAYLOAD_OFFSET; i < 79+UDP_PACKET_PAYLOAD_OFFSET; i++)
put_vga_char(receive_buffer[i], i-UDP_PACKET_PAYLOAD_OFFSET, current_line);
for (i = UDP_PACKET_PAYLOAD_OFFSET+79; receive_buffer[i] != 0; i++)
put_vga_char(receive_buffer[i], i-UDP_PACKET_PAYLOAD_OFFSET-79, current_line+1);
current_line++;
current_line++;
}
else if (current_line == 25 && receive_buffer_length < 79)
{
for (k = 26; k < 409; k++)
{
for (j = 0; j < 640; j++)
{
Vga_Clr_Pixel(VGA_0_BASE, j, k);
}
}
current_line = 2;
for (i = UDP_PACKET_PAYLOAD_OFFSET; receive_buffer[i] != 0; i++)
put_vga_char(receive_buffer[i], i-UDP_PACKET_PAYLOAD_OFFSET, current_line);
current_line++;
}
else if (current_line = 24 && receive_buffer_length > 78)
{
for (k = 26; k < 409; k++)
{
for (j = 0; j < 640; j++)
{
Vga_Clr_Pixel(VGA_0_BASE, j, k);
}
}
current_line = 2;
for (i = UDP_PACKET_PAYLOAD_OFFSET; i < 79+UDP_PACKET_PAYLOAD_OFFSET; i++)
put_vga_char(receive_buffer[i], i-UDP_PACKET_PAYLOAD_OFFSET, current_line);
for (i = UDP_PACKET_PAYLOAD_OFFSET+79; receive_buffer[i] != 0; i++)
put_vga_char(receive_buffer[i], i-UDP_PACKET_PAYLOAD_OFFSET-79, current_line+1);
current_line++;
current_line++;
}
printf("\n rcvd correct checksum: %hx", checksum);
}
else
put_vga_string("Some slob tried to send you a message but his checksum was wrong.", 0, 26);
printf("\n rcvd incorrect checksum: %hx", checksum);
}
} else {
printf("Received non-UDP packet\n");
}
} else {
