Espruino loading source code from SD card?

Hmm... I was sure I'd posted this up a few days ago, but maybe I forgot to click submit:

function saveToSD(filename) {
  var addr = process.memory().flash_code_start;
  var len = process.memory().flash_start + process.memory().flash_length - addr;
  var f = E.openFile(filename,"w");
  var block = new Uint32Array(512);
  addr -= 4;
  while (len>0) {
    block = block.map(function(v){return peek32(addr+=4);});
    f.write(block.buffer);
    len -= 2048;
  }
  f.close();
}

function loadFromSD(filename) {
  var addr = process.memory().flash_code_start;
  var len = process.memory().flash_start + process.memory().flash_length - addr;
  var rom = require("STM32F1Flash");
  rom.unlock();
  console.log("Erasing...");
  for (var i=0;i<len;i+=2048) {
    rom.erase(addr+i);
  }
  console.log("Writing...");
  var f = E.openFile(filename,"r");
  var block = new Uint32Array(512);
  addr -= 4;
  while (len>0) {
    console.log("0x"+(addr+4).toString(16));
    new Uint8Array(block.buffer).set(f.read(2048));
    block.forEach(function(v){rom.write(addr+=4,v);});
    len -= 2048;
  }
  f.close();
}

So:

• Get your program as you want it
  
• Call save()
  
• Load this script into Espruino and run saveToSD('myfile.bin');
  
  

Then to load in a new Espruino:

• Load the script and run loadFromSD('myfile.bin')
  
  

So if you wanted to allow Espruino to auto-update, you'd make sure that the code that you saved on to flash contained something like this:

function loadFromSD(filename) {
  var addr = process.memory().flash_code_start;
  var len = process.memory().flash_start + process.memory().flash_length - addr;
  var rom = require("STM32F1Flash");
  rom.unlock();
  console.log("Erasing...");
  for (var i=0;i<len;i+=2048) {
    rom.erase(addr+i);
  }
  console.log("Writing...");
  var f = E.openFile(filename,"r");
  var block = new Uint32Array(512);
  addr -= 4;
  while (len>0) {
    console.log("0x"+(addr+4).toString(16));
    new Uint8Array(block.buffer).set(f.read(2048));
    block.forEach(function(v){rom.write(addr+=4,v);});
    len -= 2048;
  }
  f.close();
}

function onInit() {
  if (MYGPIO.read()) {
    LED1.set();
    loadFromSD('update.bin');
    LED1.reset();    
    LED2.set();    
  }
}

and then the process is:

• Insert card
  
• connect MYGPIO to 3.3v
  
• reset Espruino
  
• Wait until the red LED goes out and the green one lights
  
• connect MYGPIO to 0v
  
• reset Espruino