MIPS...

lemon32767 · May 24, 2021 · d645f18 · d645f18
1 parent b5b0330
commit d645f18
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Showing 3 changed files with 25 additions and 3 deletions.
diff --git a/.gitignore b/.gitignore
@@ -1 +1,3 @@
+node_modules/
+package-lock.json
 *.xcf
diff --git a/mips.html b/mips.html
@@ -8,7 +8,7 @@
   <style>
 textarea {
   resize: none;
-  width: 40%;
+  width: 45%;
   font-size: 120%;
   font-family: monospace;
 }
@@ -17,7 +17,7 @@
 </head>
 
 <body>
-  <div style="width: 90%; margin: 0 auto; padding-left: 12%;">
+  <div style="width: 85%; margin: 0 auto; padding-left: 10%;">
     <h2>MIPS Assembler</h2>
     <p>Input MIPS assembly code below. Labels, .org and simple .word directives are also recognized. Comments start with ';' and extend to the end of the line.</p>
     <textarea wrap='off' rows="15" id="assembler-input" placeholder="MIPS assembly input" spellcheck="false"></textarea>
@@ -31,6 +31,8 @@ <h2>MIPS Disassembler</h2>
     <textarea wrap='off' rows="15" id="disassembler-input" placeholder="MIPS machine code in hex" spellcheck="false"></textarea>
     <textarea wrap='off' rows="15" readonly id="disassembler-output" placeholder="Disassembler output"></textarea>
     <br>
+    <label>.org (Start Address) </label><input style="font-family: monospace;" type='text' id="disassembler-org" size="8" placeholder="00000000" spellcheck="false">
+    <br>
     <button onclick="disassembleAndPresent();">disassemble</button>
   </div>
 

diff --git a/mips.js b/mips.js
@@ -493,7 +493,13 @@ function assembleAndPresent() {
 function disassembleAndPresent() {
   let out = $('disassembler-output');
   try {
-    let insns = disassembleListing($('disassembler-input').value, 0);
+    const org = parseInt($('disassembler-org').value, 16) || 0;
+    if (org > 0xFFFFFFFF || org < 0)
+      throw "! Invalid starting address (out of range) " + rightpad(org.toString(16), 8, "0");
+    else if ((org & 3) != 0)
+      throw "! Invalid starting address (unaligned) " + rightpad(org.toString(16), 8, "0");
+
+    let insns = disassembleListing($('disassembler-input').value, org);
     out.value = '';
     for (const insn of insns) {
       out.value += int2hex(insn[0]) + ':   ' + int2hex(insn[1]) + '    '
@@ -504,3 +510,15 @@ function disassembleAndPresent() {
     out.value = "! Error!!\n" + e;
   }
 }
+
+window.onload = () => {
+  let disasmOrgPrevVal = $('disassembler-org').value || 0;
+  $('disassembler-org').oninput = (e) => {
+    // revert edit if not a valid hex address
+    const newval = e.target.value;
+    if (newval.length && !newval.match(/^[0-9A-Fa-f]+$/))
+      e.target.value = disasmOrgPrevVal;
+    else
+      disasmOrgPrevVal = e.target.value;
+  };
+};