XLTF7267-BHA+: Document how to change the PLOAM password (#212)

* Fix typo in the software version string

* Add PLOAM password settings

* Remove a wrong warning

* Update max PLOAM length

* Remove misleading warning

* Update _ont_xgs/ont-hisense-ltf7267-bha+.md

* Apply suggestions from code review

* add nanomad js script

* fix js

* Add missing braces

---------

Co-authored-by: Simone Bortolin <simonebortolin@users.noreply.github.com>

Author: nanomad

_ont_xgs/ont-hisense-ltf7267-bha+.md

@@ -307,6 +307,95 @@ INT CFG_ID_PON_VSSN = 0xAABBCCDD;
 
 Reboot ONT to apply the change
 
+## Setting ONU GPON PLOAM password
+
+### Web procedure
+
+<form id="hisense-ploam" novalidate>
+    <div class="form-floating mb-3">
+        <input type="text" class="form-control" placeholder="PLOAM in ASCII" name="ploam" id="ploam" required>
+        <label for="ploam">PLOAM in ASCII</label>
+        <div class="invalid-feedback">
+            Please provide a valid PLOAM password.
+        </div>
+    </div>
+    <div class="mb-3">
+        <input type="submit" class="btn btn-primary" value="Encode!">
+    </div>
+    <div class="language-plaintext highlighter-rouge">
+        <div class="highlight">
+            <pre class="highlight" id="ploam-encoded">
+            </pre>
+        </div>
+    </div>
+</form>
+
+<script type="text/javascript" src="/assets/js/LTF7267-BHA-ploam.js"></script>
+<script type="text/javascript">
+    var hisensePloamForm = document.getElementById('hisense-ploam');
+    var hisenseResult = document.getElementById('ploam-encoded');
+    hisensePloamForm.addEventListener('submit', (event) => {
+        event.preventDefault();
+        if (!hisensePloamForm.checkValidity()) {
+            event.preventDefault();
+        } else {
+            const data = new URLSearchParams(new FormData(hisensePloamForm));
+            hisenseResult.innerHTML = hisensePloam(data.get('ploam'));
+        }
+    });
+</script>
+
+
+### Normal procedure
+
+This ONT seems to be supporting a PLOAM password up to 288 bits in lenghth (36 ASCII characters, 72 Hex digits).
+
+The PLOAM password is stored into 32 bit chunks (4 ASCII characters / 8 Hex digits), each byte swapped. 
+
+So, starting from the following PLOAM in ASCII format
+
+```
+A1B2C3D4E5
+```
+
+It gets translated into the following HEX value:
+
+```
+0x41314232433344344535
+```
+
+Which is then split into the following blocks (the last block gets padded with 0 to reach 8 digits)
+
+```
+BLOCK 0: 0x41314232
+BLOCK 1: 0x43334434
+BLOCK 2: 0x45350000
+```
+
+Each block is then byte swapped (i.e. read each sequence of two digits from right to left)
+
+```
+BLOCK 0: 0x32423141
+BLOCK 1: 0x34443343
+BLOCK 2: 0x00003545
+```
+
+And then you can finally persist it by changing the configuration file
+
+```sh
+# vi /config/scfg.txt
+```
+
+Append lines below to the file and save it to change the PLOAM password
+
+```
+INT             CFG_ID_PON_REGISTRATION_ID0                                         = 0x32423141;
+INT             CFG_ID_PON_REGISTRATION_ID1                                         = 0x34443343;
+INT             CFG_ID_PON_REGISTRATION_ID2                                         = 0x00003545;
+```
+
+Reboot the ONT to apply the change.
+
 
 ## Setting ONU GPON LOID and LOID password
 
@@ -330,7 +419,7 @@ Reboot ONT to apply the change
 
 ```sh
 # fw_setenv img_version0 20220527052622
-# fw_setenv img_version0 20220527052622
+# fw_setenv img_version1 20220527052622
 ```
 
 Reboot ONT to apply the change
@@ -381,8 +470,6 @@ Reboot ONT to apply the change
 
 ## Changing OMCC Version
 
-{% include alert.html content="In Italy, if you are under some Huawei OLT it's mandatory to use 0xA3, while on Alcatel 0xB4, otherwise you will get O5 status but no MIBs - Note that this can be quirk of TIM Italy" alert="Warning" icon="svg-warning" color="red" %}
-
 
 ```sh
 # vi /config/scfg.txt

assets/js/LTF7267-BHA-ploam.js

@@ -0,0 +1,28 @@
+function hexEncode(str){
+    var hex, i;
+
+    var result = "";
+    for (i=0; i<str.length; i++) {
+        hex = str.charCodeAt(i).toString(16);
+        result += hex.padStart(2, "0");
+    }
+
+    return result;
+}
+
+function hisensePloam(ascii_ploam) {
+    var hex_ploam = hexEncode(ascii_ploam);
+    var hex_padded_ploam = hex_ploam.padEnd(72, "0");
+    var array =[];
+    for (i = 0; i<9; i++) {
+        ploam_segment = hex_padded_ploam.slice(i*8, (i+1)*8);
+        new_ploam_segment = "";
+        for(j = 4; j>0; j--) {
+            new_ploam_segment = new_ploam_segment + ploam_segment.slice((j-1)*2, j*2);
+        }
+        if(new_ploam_segment !== "00000000") {
+            array.push("INT             CFG_ID_PON_REGISTRATION_ID"+i+"                                        = 0x"+new_ploam_segment+";");
+        }
+    }
+    return array.join("\n");
+}