Buffer size TCP/IP Lwip

[shyam457]

Hi,
I am working on a project using the zynq zc702 board. I want to accept a file from the PC over ethernet and then store it onto DDR memory of the processor. Then I want to process the data from the DDR and store the result onto BRAM. 
So, for the first part of it I want to save the data onto DDR. I have started working with the echo server example of lwip provided.
And I wanted to know the size of the file received over ethernet. Is it possible?? Is the variable len provided in the echoserver example giving that size?? Also how do I store this data onto the DDR?? Can I do it directly from the pbuf??

[berkeraliisik]

Hi,

You can start Tftp Server Example. Echo Server demonstrates bidirectional data transfer. If the file format of your data doesn't matter(e.g. array data of image pixels) also you can use Echo Server example. There is a structure in LwIP stack. You also access size of payload using one of the structure field.  

[balkris]

http://www.xilinx.com/support/documentation/application_notes/xapp1026.pdf
http://www.xilinx.com/support/answers/51779.html

[shyam457]

Hi, thanks for the replies.
I started working with the echo.c example. I found files platform_zynq.c, platform_ppc.c, platform_mb.c and platform_zynqmp.c. What are these files for?? Is it necessary for Ethernet TCP/IP??
Also instead of echo back I modified the code calling a function ddr_store in its place (to store the data to ddr). I stored the data p->payload into a char * ddrin and the length p->len to a int variable ddrlen and passed them onto the ddr_store().
So for me to write to the ddr, I have to use 32 bit data transfers. So, is the p->len specifying the number of bytes of data that have been received????

[shyam457]

Hi, just another doubt. I tried to setup the telnet connection between PC and ZC702 using Teraterm. I gave the Host address to be the host address of the PC in Teraterm. But it shows connection refused. Why is that?? Could someone tell me the steps of setting it up??

[balkris]

check this document
http://www.xilinx.com/products/boards/ml501/ml501_10.1_1/docs/ml501_overview_setup.pdf

http://www.xilinx.com/support/documentation/boards_and_kits/ug668_ml605_gsg_axi.pdf

http://opencores.org/uploads/1362059752_xapp1026.pdf

[shyam457]

Hi, I looked into the documents. I gave the IP address of both PC and zynq board to be in the same subnet and used teraterm to create the connection. But when I ping the zynq board, it shows Destination unreachable. Could you tell me how to setup this ethernet link?? I wish to send a binary file from PC to the zynq board over ethernet.