add method to get the actual size of the flash

Author: ficeto

cores/esp8266/Esp.cpp

@@ -158,6 +158,11 @@ uint32_t EspClass::getFlashChipId(void)
     return spi_flash_get_id();
 }
 
+uint32_t EspClass::getFlashChipRealSize(void)
+{
+    return (1 << ((spi_flash_get_id() >> 16) & 0xFF));
+}
+
 uint32_t EspClass::getFlashChipSize(void)
 {
     uint32_t data;

cores/esp8266/Esp.h

@@ -90,6 +90,9 @@ class EspClass {
         uint8_t getCpuFreqMHz(void);
 
         uint32_t getFlashChipId(void);
+        //gets the actual chip size based on the flash id
+        uint32_t getFlashChipRealSize(void);
+        //gets the size of the flash as set by the compiler
         uint32_t getFlashChipSize(void);
         uint32_t getFlashChipSpeed(void);
         FlashMode_t getFlashChipMode(void);