Part 13 - Add bank of registers inside PL and access via Webserver

This tutorial details the steps required to add a general purpose bank of registers inside the Programmable Logic part of the FPGA. Control of these registers shall be via the Webserver, which will be enhanced to allow access to more than just one register. The peek & CGI access will be updated to use the binaries instead of the scripts that call the binaries. Note Part 17 of this tutorial is newly added and is a prerequisite for this part.

Setup Xilinx design environment for the 2021.2 toolset.

steve@Desktop:~$ xilinx
Xilinx tools available tools at /opt/Xilinx :-
1) 2021.2 - Vivado - SDK - Vitis - PetaLinux
0) Exit
Please select tools required or exit : 1

Tools are as follows :-
vivado @ /opt/Xilinx/Vivado/2021.2/bin/vivado
vitis @ /opt/Xilinx/Vitis/2021.2/bin/vitis
petalinux-build @ /opt/Xilinx/PetaLinux/2021.2/tool/tools/common/petalinux/bin/petalinux-build

Change the present working directory to be the project directory.

steve@Desktop:~$ cd ~/projects/zedboard_leds_switches

Launch Vivado quietly from a Terminal.

steve@Desktop:~/projects/zedboard_leds_switches$ vivado -nojournal -nolog -notrace fw/vivado/project.xpr &

To create an AXI4-Lite peripheral (register bank) navigate Tools » Create and Package New IP....

In the Create and Package New IP dialog click Next to proceed. Missing Image!

Select Create AXI4 Peripheral in the Create and Package New IP - Create Peripheral, Package IP or Package a Block Design dialog and click Next to proceed. Missing Image!

Populate the following details in the Create and Package New IP - Peripheral Details dialog and click Next to proceed.

Name: register_bank
Version: 1.0
Display name: AXI Register Bank
Description: General purpose AXI register bank
IP location: /home/steve/zedboard_leds_switches/fw/src/ip_repo

In the Create and Package New IP - Add Interfaces dialog leave the defaults as shown and click Next to proceed. Missing Image!

Review the information provided in the Create and Package New IP - Create Peripheral dialog and click Finish to proceed. Missing Image!

Quite a few useful files have now been created in the ip_repo directory, including a testbench that uses the Xilinx AXI4 Verification IP. The two main files of interest are the HDL sources, which can be found in the hdl directory. Examine these to get a better understanding of what they are doing. The operational code is provided in register_bank_v1_0_S00_AXI.v along with a wrapper provided in register_bank_v1_0.v.

steve@Desktop:~/projects/zedboard_leds_switches$ subl fw/src/ip_repo/register_bank_1.0/hdl/{register_bank_v1_0_S00_AXI.v,register_bank_v1_0.v}

To open the existing block design click on Open Block Design under IP INTEGRATOR. Get a better view of the Block Design by clicking on its Float Missing Image!

icon.

Double click on the AXI GPIO module to begin re-customization. Change the Default Output Value of GPIO to 0x00000081 so the updated PL design is easily identifiable from the previous one. Click OK to commit the changes. Missing Image!

Add the newly created peripheral to the block design by clicking on Add IP Missing Image!

and then selecting AXI Register Bank from the context menu. Missing Image!

Connect the Register Bank to the rest of the system by clicking on Run Connection Automation.

In the Run Connection Automation dialog tick All Automation and click OK to proceed. Missing Image!

Verify the block design is error free by clicking on the Validate Design Missing Image!

icon. All being well the Validation successful dialog should now appear. Missing Image!

Check the address map assignment inside the Address Editor under the BLOCK DESIGN section. The register_bank_0 module should have a Master Base Address of 0x43C0_0000 and a Range of 64K, if not change them. Missing Image!

Save the Block Design.

Update the simple testbench to include the new functionality.

Details to follow...

steve@Desktop:~/projects/zedboard_leds_switches$ subl fw/src/testbench/testbench.sv

testbench.sv

//
// File .......... testbench.sv
// Author ........ Steve Haywood
// Version ....... 2.0
// Date .......... 22 December 2021
// Description ...
//   Very simple testbench to check correct connectivity of the block diagram.
// Uses the Zynq Verification IP suite to read/write the GPIO LED register and
// read the GPIO switch register.
// 


timeunit      1ns;
timeprecision 1ps;


module testbench;

  // Constants
  localparam [31:0] led_addr = 32'h41200000;
  localparam [31:0] sws_addr = 32'h41200008;
  localparam [31:0] led_init = 32'h00000018;
  localparam [31:0] led_next = 32'h00000081;
  localparam [ 7:0] sws_next =  8'b11000011;
  localparam [31:0] reg_addr = 32'h43C00000;


  // Signals
  wire       ps_clk;
  wire       ps_porb;
  wire       ps_srstb;
  bit [ 7:0] leds_8bits;
  bit [ 7:0] sws_8bits;
  bit        clk;
  bit        resetn;
  bit        bresp;
  bit [31:0] rdata;
  bit        rresp;


  // 50MHz Clock
  always #10 clk = !clk;


  // Reset
  initial begin
    repeat(20)
      @(posedge clk);
    resetn = 1'b1;
  end


  // Drive PL Clock & Reset
  assign ps_clk   = clk;
  assign ps_porb  = resetn;
  assign ps_srstb = resetn;


  // Stimulus
  initial begin
    // Allow reset time to work

    @(posedge resetn);
    repeat(10)
      @(posedge clk);

    // Reset PL
    testbench.system_wrapper_i.system_i.processing_system7_0.inst.fpga_soft_reset(32'h1);
    testbench.system_wrapper_i.system_i.processing_system7_0.inst.fpga_soft_reset(32'h0);

    // Read GPIO LED Register
    testbench.system_wrapper_i.system_i.processing_system7_0.inst.read_data(led_addr, 4, rdata, rresp);
    $display ("Read of GPIO LED Register = 32'h%x (%s)", rdata, (rdata == led_init) ? "expected" : "unexpected");

    // Write GPIO LED Register
    testbench.system_wrapper_i.system_i.processing_system7_0.inst.write_data(led_addr, 4, led_next, bresp);

    // Read GPIO LED Register
    testbench.system_wrapper_i.system_i.processing_system7_0.inst.read_data(led_addr, 4, rdata, rresp);
    $display ("Read of GPIO LED Register = 32'h%x (%s)", rdata, (rdata == led_next) ? "expected" : "unexpected");

    // Set some of the switches to 'on'
    sws_8bits = sws_next;

    // Read GPIO Switch Register
    testbench.system_wrapper_i.system_i.processing_system7_0.inst.read_data(sws_addr, 4, rdata, rresp);
    $display ("Read of GPIO Switch Register = 32'h%x (%s)", rdata, (rdata == sws_next) ? "expected" : "unexpected");

    // Write Register Bank Registers
    for (int i = 0; i < 'h10; i = i + 4)
      testbench.system_wrapper_i.system_i.processing_system7_0.inst.write_data(reg_addr + i, 4, 65536 + i, bresp);

    // Read Register Bank Register
    for (int i = 0; i < 'h10; i = i + 4) begin
      testbench.system_wrapper_i.system_i.processing_system7_0.inst.read_data(reg_addr, 4, rdata, rresp);
      $display ("Read of GPIO LED Register = 32'h%x (%s)", rdata, (rdata == 65536 + i) ? "expected" : "unexpected");
    end

    // All done
    $display ("That's all folks!");
    $stop;

  end


  // Unit Under Test
  system_wrapper system_wrapper_i
   (
    // LEDs
    .leds_tri_o        ( leds_8bits ),  // O:LEDs
    // Switches
    .switches_tri_i    ( sws_8bits  ),  // I:Switches
    // System
    .DDR_addr          (            ),  // B:Address
    .DDR_ba            (            ),  // B:Bank Address
    .DDR_cas_n         (            ),  // B:Column Address Select
    .DDR_ck_n          (            ),  // B:Clock (Neg)
    .DDR_ck_p          (            ),  // B:Clock (Pos)
    .DDR_cke           (            ),  // B:Clock Enable
    .DDR_cs_n          (            ),  // B:Chip Select
    .DDR_dm            (            ),  // B:Data Mask
    .DDR_dq            (            ),  // B:Data Input/Output
    .DDR_dqs_n         (            ),  // B:Data Strobe (Neg)
    .DDR_dqs_p         (            ),  // B:Data Strobe (Pos)
    .DDR_odt           (            ),  // B:Output Dynamic Termination
    .DDR_ras_n         (            ),  // B:Row Address Select
    .DDR_reset_n       (            ),  // B:Reset
    .DDR_we_n          (            ),  // B:Write Enable
    .FIXED_IO_ddr_vrn  (            ),  // B:Termination Voltage
    .FIXED_IO_ddr_vrp  (            ),  // B:Termination Voltage
    .FIXED_IO_mio      (            ),  // B:Peripheral Input/Output
    .FIXED_IO_ps_clk   ( ps_clk     ),  // B:System Reference Clock
    .FIXED_IO_ps_porb  ( ps_porb    ),  // B:Power On Reset
    .FIXED_IO_ps_srstb ( ps_srstb   )   // B:External System Reset
   );


endmodule

Direct download available here :-

steve@Desktop:~/projects/zedboard_leds_switches$ wget https://spacewire.co.uk/tutorial/shared/repos/0014/zedboard_leds_switches/fw/src/testbench/testbench.sv -O fw/src/testbench/testbench.sv

Check out the changes.

steve@Desktop:~/projects/zedboard_leds_switches$ git difftool fw/src/testbench/testbench.sv

Generate the programmable logic bitstream by clicking on Generate Bitstream under the PROGRAM AND DEBUG heading inside the Flow Navigator section. Missing Image!

Export the hardware platform by selecting File » Export » Export Hardware... from the main menu. Include the bitstream in the exported hardware file and save as ~/projects/zedboard_leds_switches/fw/system_wrapper.xsa.

Add and commit the new & updated files, create annotated tags and push the commits & tags up to the remote repositories.

steve@Desktop:~/projects/zedboard_leds_switches$ git add fw/src/ip_repo
steve@Desktop:~/projects/zedboard_leds_switches$ git commit -a -m "Added general purpose AXI register bank."
steve@Desktop:~/projects/zedboard_leds_switches$ git push
steve@Desktop:~/projects/zedboard_leds_switches$ git tag -a v2.0 -m "ZYNQ, GPIO & Register Bank"
steve@Desktop:~/projects/zedboard_leds_switches$ git push origin v2.0

If not already, connect up the hardware as follows :-

Xubuntu PC USB ⇄ Zedboard USB JTAG/Debug
Xubuntu PC USB ⇄ Zedboard USB UART
Zedboard Ethernet ⇄ Router
Xubuntu PC Ethenet ⇄ Router
Router ⇄ Internet

Set the boot mode jumpers on the Zedboard for JTAG. Missing Image!

Power on the Zedboard.

If not already running, open up a new terminal and launch the MiniCom terminal emulator.

steve@Desktop:~$ minized

Welcome to minicom 2.7.1

OPTIONS: I18n
Compiled on Dec 23 2019, 02:06:26.
Port /dev/ttyACM0, 06:34:25

Press CTRL-A Z for help on special keys

If not already, deploy the PetaLinux image via JTAG.

steve@Desktop:~/projects/zedboard_leds_switches$ cd ../zedboard_linux/os/petalinux
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ petalinux-boot --jtag --prebuilt 3

The Programmable Logic part of the FPGA can be reloaded while Linux is running without requiring a Linux reboot. To achieve this safely the interfaces between the PL & PS must be inactive and not transferring data.

Program the PL from Vivado by clicking on Open Hardware Manager under PROGRAM AND DEBUG. Missing Image!

In the HARDWARE MANAGER click on Open target and select Auto Connect from the context menu. Missing Image!

In the HARDWARE MANAGER click on Program device. Missing Image!

In the Program Device dialog click Program to program the PL. Missing Image!

All being well there should now exist four 32-bit registers within the address space 0x43C0_0000 to 0x43C0_000F.

Using the Client URL (curl) command enter the following URL's to command the peek & poke CGI binaries to read & write from & to the address space.

steve@Desktop:~/projects/zedboard_linux/os/petalinux$ curl -w "\nReceived %{size_download} bytes\n" "http://192.168.2.87/cgi-bin/peek?0x43C00000"
0x00000000
Received 10 bytes
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ curl -w "\nReceived %{size_download} bytes\n" "http://192.168.2.87/cgi-bin/poke?0x43C00000&0x456789ab"
Success
Received 7 bytes
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ curl -w "\nReceived %{size_download} bytes\n" "http://192.168.2.87/cgi-bin/peek?0x43C00000"
0x456789AB
Received 10 bytes

Edit the existing webpage to enhance its peek & poke capabilities such that multiple registers can be accessed. Add in global controls for the multiple registers and also file access so the register configuration can be saved and re-loaded.

steve@Desktop:~/projects/zedboard_linux/os/petalinux$ cd ../..

steve@Desktop:~/projects/zedboard_linux$ subl os/petalinux/project-spec/meta-user/recipes-apps/website/files/cgi-bin/index.cgi

index.cgi

#!/bin/sh

# Output Header
printf "Content-type: text/html\n\n"

# Get information
sys_host=$(hostname)
sys_time=$(date)
sys_load=$(awk '{print $1}' /proc/loadavg)
sys_up=$(awk '{print $1}' /proc/uptime)
cpu_model=$(grep model /proc/cpuinfo | cut -d : -f2 | tail -1 | sed 's/\s//')
cpu_cores=$(grep -c ^processor /proc/cpuinfo)
mem_total=$(free -m | awk 'NR==2{print $2}')
mem_used=$(free -m | awk 'NR==2{print $3}')
mem_free=$(free -m | awk 'NR==2{print $4}')
net_mac=$(cat /sys/class/net/eth0/address)
net_ip_loc=$(ip a | grep inet | grep -vw lo | grep -v inet6 | cut -d \/ -f1 | sed 's/[^0-9\.]*//g')
net_ip_ext=$(wget -q -O- http://ipecho.net/plain)

# Output HTML
cat <<EOF
<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<link href="../styles.css" rel="stylesheet">
<title>Zedboard Webserver</title>
</head>
<body onload="add_register()">

<div class="section"><h2>Zedboard Webserver</h2></div>

<div class="section"><img src="../zedboard.png" alt="Missing Image!"></div>

<div class="section">

<table>
<tr><th colspan="2">System</th></tr>
<tr><td>Hostname</td>
<td>${sys_host}</td>
</tr><tr><td>Time</td><td>${sys_time}</td></tr>
<tr><td>Uptime</td><td><span id="uptime_text">${sys_up}</span> seconds <button onclick="get_uptime()">Refresh</button> Auto :
<select id="uptime" onchange="uptime();">
  <option value="0">Off</option>
  <option value="1">1s</option>
  <option value="5">5s</option>
</select>
</td></tr>
</table>

<table>
<tr><th colspan="2">CPU</th></tr>
<tr><td>Model</td>
<td>${cpu_model}</td></tr>
<tr><td>Cores</td><td>${cpu_cores}</td></tr>
<tr><td>Load</td><td>${sys_load}</td></tr>
</table>

<table>
<tr><th colspan="2">Memory</th></tr>
<tr><td>Total</td><td>${mem_total} Mb</td></tr>
<tr><td>Used</td><td>${mem_used} Mb</td></tr>
<tr><td>Free</td><td>${mem_free} Mb</td></tr>
</table>

<table>
<tr><th colspan="2">Network</th></tr>
<tr><td>MAC Address</td><td>${net_mac}</td></tr>
<tr><td>Internal IP</td><td>${net_ip_loc}</td></tr>
<tr><td>External IP</td><td>${net_ip_ext}</td></tr>
</table>

</div>

<div class="section">
<table id="registers">
<tr>
<th>Address</th>
<th>Peek Value</th>
<th>Sel</th>
<th>Peek</th>
<th>Status</th>
<th>Copy</th>
<th>Poke Value</th>
<th>Sel</th>
<th>Poke</th>
<th>Status</th>
<th>Description</th>
</tr>
</table>
<br><br>
<input title="Add new row to end of address table" type="button" value="Add" onclick="add_row()">
<select title="Set type of row to add to address table" id="type">
  <option value="0">Register</option>
  <option value="1">Section</option>
</select>
<input title="Remove last address from table" type="button" value="Remove" onclick="rem_register()">
<input title="Peek all selected addresses in table" type="button" value="Peek All" onclick="peek_all()">
<input title="Copy all table peek values into poke values" type="button" value="Copy All" onclick="copy_all()">
<input title="Poke all selected addresses in table" type="button" value="Poke All" onclick="poke_all()">
Peek Refresh :
<select title="Set timer interval for automatic peek of table addresses" id="timer" onchange="timer()">
  <option value="0">Off</option>
  <option value="1">1s</option>
  <option value="5">5s</option>
</select>
Number Format :
<select title="Set number format for peek and poke values" id="format" onchange="format()">
  <option value="0">Hexadecimal</option>
  <option value="1">Unsigned</option>
</select>
Configuration :
<button title="Create configuration file from table" onclick="create_config()">Create...</button> <a title="Right click and Save Link As... to locate and rename this file" download="config.txt" id="download" href="" style="display: none">config.txt</a>
<input title="Read configuration file into table" type="file" id="load_config">
</div>

<div class="section">Designed by Steve Haywood @ 2021</div>

<script src="../uptime.js"></script>

</body>
</html>
EOF

Direct download available here :-

steve@Desktop:~/projects/zedboard_linux$ wget https://spacewire.co.uk/tutorial/shared/repos/0015/zedboard_linux/os/petalinux/project-spec/meta-user/recipes-apps/website/files/cgi-bin/index.cgi -O os/petalinux/project-spec/meta-user/recipes-apps/website/files/cgi-bin/index.cgi

Check out the changes.

steve@Desktop:~/projects/zedboard_linux$ git difftool os/petalinux/project-spec/meta-user/recipes-apps/website/files/cgi-bin/index.cgi

Firstly download the following 3 image files ( Missing Image!

) into /home/steve/zedboard_linux/os/petalinux/project-spec/meta-user/recipes-apps/website/files. Note the second & third images are a play-once animations.

steve@Desktop:~/projects/zedboard_linux$ wget https://spacewire.co.uk/tutorial/shared/repos/0015/zedboard_linux/os/petalinux/project-spec/meta-user/recipes-apps/website/files/{amber.gif,green.gif,red.gif} -P os/petalinux/project-spec/meta-user/recipes-apps/website/files

Now edit the existing Javascript to add in the functions required to support the enhanced website. Also change the status reporting for the Peek & Poke operations to use the image files, adding to this a status message that appears when the mouse hovers over an image. The Javascript at this point is updated to be more flexible for future use. Note the addition of file operations for configuration file access.

steve@Desktop:~/projects/zedboard_linux$ subl os/petalinux/project-spec/meta-user/recipes-apps/website/files/uptime.js

uptime.js

// Requests
var timer_uptime;
var timer_peek_all;

// Get uptime
function get_uptime(reg) {
  var url = "cgi-bin/uptime.cgi";
  if (window.XMLHttpRequest) {
    var ajaxReq = new XMLHttpRequest();
    ajaxReq.onreadystatechange = function() {
      if (ajaxReq.readyState == 4 && ajaxReq.status == 200) {
        var respText = ajaxReq.responseText;
        txtObj = document.getElementById("uptime_text");
        if (txtObj) {
          txtObj.innerHTML = respText;
        }
      }
    }
    ajaxReq.open("POST", url, true);
    ajaxReq.send(null);
  }
}

// Update uptime timer
function uptime() {
  clearInterval(timer_uptime);
  var uptime = document.getElementById("uptime");
  var interval = uptime.value;
  if (interval > 0) {
    timer_uptime = setInterval("get_uptime()", 1000 * interval);
  }
}

// Update peek_all timer
function timer() {
  clearInterval(timer_peek_all);
  var timer = document.getElementById("timer");
  interval = timer.value;
  if (interval > 0) {
    timer_peek_all = setInterval("peek_all()", 1000 * interval);
  }
}

// Update number format
function format() {
  var table = document.getElementById("registers");
  var rows = table.rows.length;
  var peek;
  var poke;
  for (var index = 0; index < rows; index++) {
    peek = document.getElementById("peek_" + index);
    if (peek) {
      peek.value = fmtUnsignedLong(parseInt(peek.value));
    }
    poke = document.getElementById("poke_" + index);
    if (poke) {
      poke.value = fmtUnsignedLong(parseInt(poke.value));
    }
  }
}

// Convert unsigned long to dec/hex string
function fmtUnsignedLong(value) {
  var format = document.getElementById("format");
  var hexStr;
  if (format.value == 0) {
    hexStr = value.toString(16).toUpperCase();
    hexStr = "0x" + "00000000".substr(0, 8 - hexStr.length) + hexStr;
  } else {
    hexStr = value.toString(10);
  }
  return hexStr;
}

// Copy peek to poke
function copy(reg) {
  var peek = document.getElementById("peek_" + reg);
  if (peek) {
    var poke = document.getElementById("poke_" + reg);
    if (poke) {
      poke.value = peek.value;
    }
  }
}

// Copy all peek to poke
function copy_all() {
  var table = document.getElementById("registers");
  var rows = table.rows.length - 1;
  for (var index = 0; index < rows; index++) {
    copy(index);
  }
}

// Peek address & display result
function peek(reg) {
  var url = "/cgi-bin/peek?" + document.getElementById("addr_" + reg).value;
  if (window.XMLHttpRequest) {
    var ajaxReq = new XMLHttpRequest();
    ajaxReq.onreadystatechange = function() {
      if (ajaxReq.readyState == 4 && ajaxReq.status == 200) {
        var respText = ajaxReq.responseText;
        var img_obj = document.getElementById("speek_" + reg);
        // Unique number is added to image to avoid caching issues on separate animations
        const now = Date.now();
        if (respText.substr(0,6) == "Error:") {
          img_obj.src = "../red.gif?" + now;
          img_obj.title = "Last peek failed : " + respText.substr(7);
        } else {
          img_obj.src = "../green.gif?" + now;
          img_obj.title = "Last peek successful";
          document.getElementById("peek_" + reg).value = fmtUnsignedLong(parseInt(respText));
        }
      }
    }
    ajaxReq.open("POST", url, true);
    ajaxReq.send(null);
  }
}

// Peek all selected addresses in section
function peek_section(row) {
  var obj_sel;
  do {
    row++;
    obj_sel = document.getElementById("peek_sel_" + row);
    if (obj_sel) {
      if (obj_sel.checked) {
        peek(row);
      }
    }
  } while (obj_sel);
}

// Peek all selected addresses in table
function peek_all() {
  var table = document.getElementById("registers");
  var rows = table.rows.length - 1;
  for (var index = 0; index < rows; index++) {
    const obj_sel = document.getElementById("peek_sel_" + index);
    if (obj_sel) {
      if (obj_sel.checked) {
        peek(index);
      }
    }
  }
}

// Poke address & display result
function poke(reg) {
  var url = "/cgi-bin/poke?" + document.getElementById("addr_" + reg).value + "&" + document.getElementById("poke_" + reg).value;
  if (window.XMLHttpRequest) {
    var ajaxReq = new XMLHttpRequest();
    ajaxReq.onreadystatechange = function() {
      if (ajaxReq.readyState == 4 && ajaxReq.status == 200) {
        var respText = ajaxReq.responseText;
        var img_obj = document.getElementById("spoke_" + reg);
        // Unique number is added to image to avoid caching issues on separate animations
        const now = Date.now();
        if (respText.substr(0,6) == "Error:") {
          img_obj.src = "../red.gif?" + now;
          img_obj.title = "Last poke failed : " + respText.substr(7);
        } else {
          img_obj.src = "../green.gif?" + now;
          img_obj.title = "Last poke successful";
        }
      }
    }
    ajaxReq.open("POST", url, true);
    ajaxReq.send(null);
  }
}

// Poke all selected addresses in section
function poke_section(row) {
  var obj_sel;
  do {
    row++;
    obj_sel = document.getElementById("poke_sel_" + row);
    if (obj_sel) {
      if (obj_sel.checked) {
        poke(row);
      }
    }
  } while (obj_sel);
}

// Poke all selected addresses in table
function poke_all() {
  var table = document.getElementById("registers");
  var rows = table.rows.length - 1;
  for (var index = 0; index < rows; index++) {
    const obj_sel = document.getElementById("poke_sel_" + index);
    if (obj_sel) {
      if (obj_sel.checked) {
        poke(index);
      }
    }
  }
}

// Add row to table
function add_row() {
  const obj_type = document.getElementById("type");
  const row_type = obj_type.value;
  switch(row_type) {
    case "0":
      add_register();
      break;
    case "1":
      add_section();
      break;
    default:
      break;
  }
}

// Add row to table
function add_register(reg) {
  var table = document.getElementById("registers");
  var next = table.rows.length - 1;
  var row = table.insertRow(-1);
  var newcell;
  var addr = 0x41200000;
  if (next > 0) {
    const obj_addr = document.getElementById("addr_" + (next - 1));
    if (obj_addr) {
      addr = parseInt(document.getElementById("addr_" + (next - 1)).value) + 4;
    }
  }
  newcell = row.insertCell(0);
  newcell.innerHTML = '<input title="Address to peek/poke" type="text" id="addr_' + next + '" value="' + fmtUnsignedLong(addr) + '" size="10">';
  newcell = row.insertCell(1);
  newcell.innerHTML = '<input title="Value peeked at address" type="text" id="peek_' + next + '" value="0x00000000" size="10" readonly="readonly"></td>';
  newcell = row.insertCell(2);
  newcell.innerHTML = '<input title="Select address for peeking" type="checkbox" id="peek_sel_' + next + '" checked></td>';
  newcell = row.insertCell(3);
  newcell.innerHTML = '<input title="Peek address" type="submit" value="Peek" onclick="peek(' + next + ')">';
  newcell = row.insertCell(4);
  newcell.innerHTML = '<img title="Peek status" id="speek_' + next + '" style="vertical-align:middle" src="../amber.gif" alt="Missing Image!">';
  newcell = row.insertCell(5);
  newcell.innerHTML = '<input title="Copy peek value into poke value" type="submit" value=">>" onclick="copy(' + next + ')">';
  newcell = row.insertCell(6);
  newcell.innerHTML = '<input title="Value to poke at address" type="text" id="poke_' + next + '" value="0x00000000" size="10">';
  newcell = row.insertCell(7);
  newcell.innerHTML = '<input title="Select address for poking" type="checkbox" id="poke_sel_' + next + '" checked></td>';
  newcell = row.insertCell(8);
  newcell.innerHTML = '<input title="Poke address" type="submit" value="Poke" onclick="poke(' + next + ')">';
  newcell = row.insertCell(9);
  newcell.innerHTML = '<img title="Poke status" id="spoke_' + next + '" style="vertical-align:middle" src="../amber.gif" alt="Missing Image!">';
  newcell = row.insertCell(10);
  newcell.innerHTML = '<input title="Description of address" type="text" id="name_' + next + '" value="Register @ ' + fmtUnsignedLong(addr) + '" size="40">';
}

// Add group row to table
function add_section(reg) {
  var table = document.getElementById("registers");
  var next = table.rows.length - 1;
  var row = table.insertRow(-1);
  var newcell;
  newcell = row.insertCell(0);
  newcell.colSpan = "3";
  newcell.innerHTML = "--- Section ---";
  newcell = row.insertCell(1);
  newcell.innerHTML = '<input title="Peek all selected addresses in section" type="submit" value="Peek" onclick="peek_section(' + next + ')">';
  newcell = row.insertCell(2);
  newcell.colSpan = "4";
  newcell.innerHTML = "--- Section ---";
  newcell = row.insertCell(3);
  newcell.innerHTML = '<input title="Poke all selected addresses in section" type="submit" value="Poke" onclick="poke_section(' + next + ')">';
  newcell = row.insertCell(4);
  newcell = row.insertCell(5);
  newcell.colSpan = "2";
  newcell.innerHTML = '<input title="Description of section" type="text" id="name_' + next + '" value="Section Description" size="40">';
}

// Remove row from table
function rem_register(reg) {
  var table = document.getElementById("registers");
  if (table.rows.length > 1) {
    table.deleteRow(-1);
  }
}

// Remove all rows from table
function remove_all() {
  var table = document.getElementById("registers");
  var rows = table.rows.length - 1;
  for (var index = 0; index < rows; index++) {
    table.deleteRow(-1);
  }
}

// Note: browser file access is made difficult for security reasons - there maybe a better way of doing file read & write.

var config_file = null;

// Create virtual configuration file from address table for user to download
function create_config() {
  var text = "";
  var table = document.getElementById("registers");
  const rows = table.rows.length - 1;
  for (var index = 0; index < rows; index++) {
    const obj_addr = document.getElementById("addr_" + index);
    if (obj_addr) { // Register type
      var addr = document.getElementById("addr_" + index).value;
      var peek_sel = document.getElementById("peek_sel_" + index).checked;
      var poke = document.getElementById("poke_" + index).value;
      var poke_sel = document.getElementById("poke_sel_" + index).checked;
      var name = document.getElementById("name_" + index).value;
      text += "reg" + "|" + addr + "|" + peek_sel + "|" + poke + "|" + poke_sel + "|"+ name + "\n";
    } else { // Section type
      var name = document.getElementById("name_" + index).value;
      text += "sec" + "|" + name + "\n";
    }
  }
  const data = new Blob([text], {type: 'text/plain'});
  if (config_file !== null) {
    URL.revokeObjectURL(config_file);
  }
  config_file = URL.createObjectURL(data);
  var link = document.getElementById('download');
  link.href = config_file;
  link.style.display = 'inline';
}

// Read configuration file and update address table
function load_config(input) {
  var file = input.target.files[0];
  if (file) {
    var reader = new FileReader();
    reader.onload = function(input) {
      var contents = input.target.result;
      const lines = contents.split(/\r\n|\n/);
      remove_all();
      lines.forEach((line) => {
        if (line.length > 0) {
          var table = document.getElementById("registers");
          var next = table.rows.length - 1;
          const values = line.split("|");
          switch(values[0]) {
            case "reg":
              add_register();
              document.getElementById("addr_" + next).value = values[1];
              if (values[2] == "false") {
                document.getElementById("peek_sel_" + next).checked = false;
              }
              document.getElementById("poke_" + next).value = values[3];
              if (values[4] == "false") {
                document.getElementById("poke_sel_" + next).checked = false;
              }
              document.getElementById("name_" + next).value = values[5];
              break;
            case "sec":
              add_section();
              document.getElementById("name_" + next).value = values[1];
              break;
            default:
              alert("Error: Unrecognized table type found (" + values[0] + "), ignoring.");
          }
        }
      });
    };
    reader.readAsText(file);
  }
}

document.getElementById('load_config').addEventListener('change', load_config, false);

Direct download available here :-

steve@Desktop:~/projects/zedboard_linux$ wget https://spacewire.co.uk/tutorial/shared/repos/0015/zedboard_linux/os/petalinux/project-spec/meta-user/recipes-apps/website/files/uptime.js -O os/petalinux/project-spec/meta-user/recipes-apps/website/files/uptime.js

Check out the changes.

steve@Desktop:~/projects/zedboard_linux$ git difftool os/petalinux/project-spec/meta-user/recipes-apps/website/files/uptime.js

Edit the BitBake recipe to add in the entries for the amber, green & red image files such that they will be installed into /srv/www.

steve@Desktop:~/projects/zedboard_linux$ subl os/petalinux/project-spec/meta-user/recipes-apps/website/website.bb

website.bb

#
# This file is the website recipe.
#

SUMMARY = "Simple website application"
SECTION = "PETALINUX/apps"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"

SRC_URI = "file://index.html"
SRC_URI += "file://uptime.js"
SRC_URI += "file://zedboard.png"
SRC_URI += "file://styles.css"
SRC_URI += "file://cgi-bin/index.cgi"
SRC_URI += "file://cgi-bin/uptime.cgi"
SRC_URI += "file://amber.gif"
SRC_URI += "file://green.gif"
SRC_URI += "file://red.gif"

FILES_${PN} += "/srv/www"

S = "${WORKDIR}"

do_install() {
     install -d ${D}/srv/www
     install -m 0644 ${S}/index.html ${D}/srv/www/index_original.html
     install -m 0644 ${S}/uptime.js ${D}/srv/www
     install -m 0644 ${S}/zedboard.png ${D}/srv/www
     install -m 0644 ${S}/styles.css ${D}/srv/www
     install -m 0644 ${S}/amber.gif ${D}/srv/www
     install -m 0644 ${S}/green.gif ${D}/srv/www
     install -m 0644 ${S}/red.gif ${D}/srv/www
     install -d ${D}/srv/www/cgi-bin
     install -m 0755 ${S}/cgi-bin/index.cgi ${D}/srv/www/cgi-bin
     install -m 0755 ${S}/cgi-bin/uptime.cgi ${D}/srv/www/cgi-bin
}

Direct download available here :-

steve@Desktop:~/projects/zedboard_linux$ wget https://spacewire.co.uk/tutorial/shared/repos/0015/zedboard_linux/os/petalinux/project-spec/meta-user/recipes-apps/website/website.bb -O os/petalinux/project-spec/meta-user/recipes-apps/website/website.bb

Check out the changes.

steve@Desktop:~/projects/zedboard_linux$ git difftool os/petalinux/project-spec/meta-user/recipes-apps/website/website.bb

Copy the modified files over to PetaLinux to check they work.

steve@Desktop:~/projects/zedboard_linux$ sshpass -p root scp os/petalinux/project-spec/meta-user/recipes-apps/website/files/cgi-bin/index.cgi root@192.168.2.87:/srv/www/cgi-bin
steve@Desktop:~/projects/zedboard_linux$ sshpass -p root scp os/petalinux/project-spec/meta-user/recipes-apps/website/files/uptime.js root@192.168.2.87:/srv/www
steve@Desktop:~/projects/zedboard_linux$ sshpass -p root scp os/petalinux/project-spec/meta-user/recipes-apps/website/files/amber.gif root@192.168.2.87:/srv/www
steve@Desktop:~/projects/zedboard_linux$ sshpass -p root scp os/petalinux/project-spec/meta-user/recipes-apps/website/files/green.gif root@192.168.2.87:/srv/www
steve@Desktop:~/projects/zedboard_linux$ sshpass -p root scp os/petalinux/project-spec/meta-user/recipes-apps/website/files/red.gif root@192.168.2.87:/srv/www

Access the webserver running on the Zedboard using a browser pointing at the Zedboard's IP address (192.168.2.87). All being well something akin to the following webpage should be displayed. Missing Image!

The controls in the Peek & Poke section of the enhanced website are as follows :-

Sel - Select peek/poke register to be used during peek/poke section/table.
Peek - Peek single register or all selected registers in the section
Copy - Copy peek value into poke value
Poke - Poke single register or all selected registers in the section
Add - Add a new register/section to the table, register address will be 4 higher than the last entry
Remove - Remove last entry from the table
Peek All - Peek all registers in the table
Copy All - Copy all table peek values into poke values
Poke All - Poke all selected registers in the table
Peek Refresh - Enable all registers in table to be peeked at a set interval
Number Format - Set the number format of the peek & poke values
Create... - Create a downloadable configuration file from the register table
Browse... - Load a configuration file into the register table

Create the above register table by using the Add button to add new registers & sections, the Address column to edit the address locations, the Poke Value column to edit the values to poke and the Description column to provide a description of what the registers & sections are used for. Poke the LEDs register and Poke two registers inside the Register Bank at addresses 0x43C00004 and 0x43C0000C. Use Peek All to peek all the registers shown in the table, Peek (section) to peek all the selected registers in a section or Peek to peek an individual register.

Create a configuration file from the address table by clicking on Create.... A generated link (config.txt) should now appear next to the Create... button. Right click on the link and select Save Link As..., set the name to zedboard_leds_switches.txt and save the file in ~/projects/zedboard_linux/os/src/other.

zedboard_leds_switches.txt

sec|AXI GPIO
reg|0x41200000|true|0x00000018|true|LEDs
reg|0x41200008|true|0x00000000|false|Switches
sec|AXI Register Bank
reg|0x43C00000|false|0x00000000|true|Register 0
reg|0x43C00004|true|0x456789AB|true|Register 1
reg|0x43C00008|false|0x00000000|true|Register 2
reg|0x43C0000C|true|0x0000FF00|true|Register 3

Direct download available here :-

steve@Desktop:~/projects/zedboard_linux$ wget https://spacewire.co.uk/tutorial/shared/repos/0015/zedboard_linux/os/src/other/zedboard_leds_switches.txt -O os/src/other/zedboard_leds_switches.txt

steve@Desktop:~/projects/zedboard_linux$ cd os/petalinux

Configure the PetaLinux project to use the exported hardware platform from the zedboard_leds_switches Vivado project.

steve@Desktop:~/projects/zedboard_linux/os/petalinux$ petalinux-config --get-hw-description ../../../zedboard_leds_switches/fw/system_wrapper.xsa

The configuration menu now appears.

Select Save to save the configuration. Missing Image!

Select Ok to confirm the save. Missing Image!

Select Exit to continue. Missing Image!

Select Exit to exit the menu. Missing Image!

Both the FPGA bitstream and enhanced website are currently soft-loaded for test purposes. Since the testing as proven successful PetaLinux can be rebuilt to include the updates and packaged ready for deployment.

steve@Desktop:~/projects/zedboard_linux/os/petalinux$ petalinux-build
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ petalinux-package --prebuilt --force

Reload PetaLinux to double check it now contains the updated files.

steve@Desktop:~/projects/zedboard_linux/os/petalinux$ petalinux-boot --jtag --prebuilt 3

All being well the following sequence of events should be observed, pay particular attention to point 2.

The blue done LED illuminates indicating the Programmable Logic (PL) has been programmed.
LED 7 and 0 illuminate indicating the bitstream from the updated zedboard_leds_switches project is in use.
The software runs on the Processor System (PS).
PetaLinux starts to boot.
The led-runner application launches and executes the expanding & contracting LED illumination sequence.
The PetaLinux login prompt appears in the terminal emulator.

Access the webserver running on the Zedboard using a browser pointing at the Zedboard's IP address (192.168.2.87). Reload the saved configuration by clicking on Browse... and selecting zedboard_leds_switches.txt from ~/projects/zedboard_linux/os/petalinux/src/other.

steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git add project-spec/hw-description/drivers
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git add project-spec/meta-user/recipes-apps/website/files/amber.gif
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git add project-spec/meta-user/recipes-apps/website/files/green.gif
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git add project-spec/meta-user/recipes-apps/website/files/red.gif
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git commit -a -m "Enhanced webpage for website application to have multiple location access into PL address space."
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git push
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git tag -a v8.0 -m "PetaLinux, Peek/Poke, LED Runner, Webserver, Peek/Poke CGI, PL Access, Style Sheet & Register Bank with XSA from zedboard_leds_switches v2.0"
steve@Desktop:~/projects/zedboard_linux/os/petalinux$ git push origin v8.0

The source files relating to this tutorial for both Firmware & OS can be obtained from Bitbucket. The Firmare repository is optional and only required if the Firmware is to be modyfied and rebuilt. The OS repository is essential as it contains both PetaLinux and a local copy of the exported hardware (firmware).

The instructions below assume that Part 1 - Installation of tools, setup of environment and creation of project area has been completed in full and that the environment has been setup as per 1. Setup environment. The root project area ~/projects should be present and contain the common project. The zedboard_leds_switches & zedboard_linux projects should NOT be present. Adjust the commands below to suit if the above differs.

Part A (optional) - Obtain firmware source, create Vivado project, build firmware & export hardware.

steve@Desktop:~$ cd ~/projects
steve@Desktop:~/projects$ git clone -b v2.0 https://bitbucket.org/spacewire_firmware/zedboard_leds_switches
steve@Desktop:~/projects$ cd zedboard_leds_switches
steve@Desktop:~/projects/zedboard_leds_switches$ create_vivado_project.sh

Do something with the Firmware (if required) then perform the following steps :-

Generate bitstream
Export hardware platform

Part B - Obtain OS source, build & deploy on Zedboard.

steve@Desktop:~$ cd ~/projects
steve@Desktop:~/projects$ git clone -b v8.0 https://bitbucket.org/spacewire_firmware/zedboard_linux
steve@Desktop:~/projects$ cd zedboard_linux/os/petalinux

If Part A was executed perform the following step :-

Update hardware platform

Do something with the OS (if required) then perform the following steps :-

Build & package PetaLinux
Setup Zedboard hardware
Launch MiniCom terminal emulator
Deploy PetaLinux on Zedboard
Check everything is working as expected

Introduction

Aims

Part 1 - Project Setup

Part 2 - Firmware Development

Part 3 - Revision Control

Part 4 - Hardware Deployment 1

Part 5 - OS Development

Part 6 - Hardware Deployment 2

Part 7 - Revision Control

Part 8 - Quickstart

1. Setup environment

2. Change present working directory

3. Launch Vivado & open project

4. Create AXI4-Lite peripheral

5. Open block design

6. Re-customize AXI GPIO

7. Add peripheral to block design

8. Edit address map

9. Update testbench

testbench.sv

10. Generate bitstream

11. Export hardware platform

12. Commit new & updated files

13. Setup Zedboard hardware

14. Launch MiniCom terminal emulator

15. Deploy PetaLinux on Zedboard

16. Program PL independently

17. Check PL is working as expected

18. Enhance website peek & poke access

index.cgi

19. Update Javascript for enhanced website

uptime.js

20. Modify BitBake recipe

website.bb

21. Quick check enhanced website is working as expected

zedboard_leds_switches.txt

22. Update hardware platform

23. Build & package PetaLinux

24. Deploy PetaLinux on Zedboard

25. Check everything is working as expected

26. Commit new & updated files

27. Obtain tutorial files from Bitbucket, create & build projects, deploy on Zedboard