Basic support for esp8266 platform

This includes empty stubs for most core Arduino functions.
Need to actually implement all those digital reads writes whatever.
Need to prebuild toolchains (xtensa-elf-lx106) for 3 platforms and put them on some download server.
Need to do the same with esptool.
Need to fix 0x40000 binary generation and add correct upload commands.
Maybe even implement uploads over WiFi.

cores/esp8266/Print.cpp

@@ -0,0 +1,248 @@
+/*
+ Print.cpp - Base class that provides print() and println()
+ Copyright (c) 2008 David A. Mellis.  All right reserved.
+ 
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+ 
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ Lesser General Public License for more details.
+ 
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ 
+ Modified 23 November 2006 by David A. Mellis
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+#include "Arduino.h"
+
+#include "Print.h"
+
+
+
+
+// Public Methods //////////////////////////////////////////////////////////////
+
+/* default implementation: may be overridden */
+size_t Print::write(const uint8_t *buffer, size_t size)
+{
+  size_t n = 0;
+  while (size--) {
+    n += write(*buffer++);
+  }
+  return n;
+}
+
+size_t Print::print(const String &s)
+{
+  return write(s.c_str(), s.length());
+}
+
+size_t Print::print(const char str[])
+{
+  return write(str);
+}
+
+size_t Print::print(char c)
+{
+  return write(c);
+}
+
+size_t Print::print(unsigned char b, int base)
+{
+  return print((unsigned long) b, base);
+}
+
+size_t Print::print(int n, int base)
+{
+  return print((long) n, base);
+}
+
+size_t Print::print(unsigned int n, int base)
+{
+  return print((unsigned long) n, base);
+}
+
+size_t Print::print(long n, int base)
+{
+  if (base == 0) {
+    return write(n);
+  } else if (base == 10) {
+    if (n < 0) {
+      int t = print('-');
+      n = -n;
+      return printNumber(n, 10) + t;
+    }
+    return printNumber(n, 10);
+  } else {
+    return printNumber(n, base);
+  }
+}
+
+size_t Print::print(unsigned long n, int base)
+{
+  if (base == 0) return write(n);
+  else return printNumber(n, base);
+}
+
+size_t Print::print(double n, int digits)
+{
+  return printFloat(n, digits);
+}
+
+size_t Print::print(const Printable& x)
+{
+  return x.printTo(*this);
+}
+
+size_t Print::println(void)
+{
+  size_t n = print('\r');
+  n += print('\n');
+  return n;
+}
+
+size_t Print::println(const String &s)
+{
+  size_t n = print(s);
+  n += println();
+  return n;
+}
+
+size_t Print::println(const char c[])
+{
+  size_t n = print(c);
+  n += println();
+  return n;
+}
+
+size_t Print::println(char c)
+{
+  size_t n = print(c);
+  n += println();
+  return n;
+}
+
+size_t Print::println(unsigned char b, int base)
+{
+  size_t n = print(b, base);
+  n += println();
+  return n;
+}
+
+size_t Print::println(int num, int base)
+{
+  size_t n = print(num, base);
+  n += println();
+  return n;
+}
+
+size_t Print::println(unsigned int num, int base)
+{
+  size_t n = print(num, base);
+  n += println();
+  return n;
+}
+
+size_t Print::println(long num, int base)
+{
+  size_t n = print(num, base);
+  n += println();
+  return n;
+}
+
+size_t Print::println(unsigned long num, int base)
+{
+  size_t n = print(num, base);
+  n += println();
+  return n;
+}
+
+size_t Print::println(double num, int digits)
+{
+  size_t n = print(num, digits);
+  n += println();
+  return n;
+}
+
+size_t Print::println(const Printable& x)
+{
+  size_t n = print(x);
+  n += println();
+  return n;
+}
+
+// Private Methods /////////////////////////////////////////////////////////////
+
+size_t Print::printNumber(unsigned long n, uint8_t base) {
+  char buf[8 * sizeof(long) + 1]; // Assumes 8-bit chars plus zero byte.
+  char *str = &buf[sizeof(buf) - 1];
+
+  *str = '\0';
+
+  // prevent crash if called with base == 1
+  if (base < 2) base = 10;
+
+  do {
+    unsigned long m = n;
+    n /= base;
+    char c = m - base * n;
+    *--str = c < 10 ? c + '0' : c + 'A' - 10;
+  } while(n);
+
+  return write(str);
+}
+
+size_t Print::printFloat(double number, uint8_t digits) 
+{ 
+  size_t n = 0;
+  
+  if (isnan(number)) return print("nan");
+  if (isinf(number)) return print("inf");
+  if (number > 4294967040.0) return print ("ovf");  // constant determined empirically
+  if (number <-4294967040.0) return print ("ovf");  // constant determined empirically
+  
+  // Handle negative numbers
+  if (number < 0.0)
+  {
+     n += print('-');
+     number = -number;
+  }
+
+  // Round correctly so that print(1.999, 2) prints as "2.00"
+  double rounding = 0.5;
+  for (uint8_t i=0; i<digits; ++i)
+    rounding /= 10.0;
+  
+  number += rounding;
+
+  // Extract the integer part of the number and print it
+  unsigned long int_part = (unsigned long)number;
+  double remainder = number - (double)int_part;
+  n += print(int_part);
+
+  // Print the decimal point, but only if there are digits beyond
+  if (digits > 0) {
+    n += print("."); 
+  }
+
+  // Extract digits from the remainder one at a time
+  while (digits-- > 0)
+  {
+    remainder *= 10.0;
+    int toPrint = int(remainder);
+    n += print(toPrint);
+    remainder -= toPrint; 
+  } 
+  
+  return n;
+}