Added a Third method.

This method runs before the NONOS SDK is started. Patches the flashchip structure that the ROM APIs reference for validating input before calling SPIEraseSector. Extracted logic from EspClass::magicFlashChipSize() to make a "C" callable function and made EspClass::magicFlashChipSize() a thin wrapper to avoid duplicating code. Use Cache_Read_Enable() to enable flash code execution to reduce IRAM usage by pre SDK starup code. Improved comments and made comment formating more consistant in erase_config.cpp. Improved issolation of debug printing.
esp8266 · mhightower83 · Dec 28, 2019 · Dec 30, 2019 · Dec 30, 2019 · Dec 30, 2019
commit 049d91bca8147fa1f0a5e675b6d27e9e470fda5f
diff --git a/cores/esp8266/Esp.cpp b/cores/esp8266/Esp.cpp
@@ -326,6 +326,36 @@ FlashMode_t EspClass::getFlashChipMode(void)
     return mode;
 }
 
+#ifdef ERASE_CONFIG_H
+// This change is only needed for method 3
+extern "C" uint32_t esp_c_magic_flash_chip_size(uint8_t byte)
+{
+    switch(byte & 0x0F) {
+        case 0x0: // 4 Mbit (512KB)
+            return (512_kB);
+        case 0x1: // 2 MBit (256KB)
+            return (256_kB);
+        case 0x2: // 8 MBit (1MB)
+            return (1_MB);
+        case 0x3: // 16 MBit (2MB)
+            return (2_MB);
+        case 0x4: // 32 MBit (4MB)
+            return (4_MB);
+        case 0x8: // 64 MBit (8MB)
+            return (8_MB);
+        case 0x9: // 128 MBit (16MB)
+            return (16_MB);
+        default: // fail?
+            return 0;
+    }
+}
+
+uint32_t EspClass::magicFlashChipSize(uint8_t byte)
+{
+    return esp_c_magic_flash_chip_size(byte);
+}
+
+#else
 uint32_t EspClass::magicFlashChipSize(uint8_t byte) {
     switch(byte & 0x0F) {
         case 0x0: // 4 Mbit (512KB)
@@ -346,6 +376,7 @@ uint32_t EspClass::magicFlashChipSize(uint8_t byte) {
             return 0;
     }
 }
+#endif
 
 uint32_t EspClass::magicFlashChipSpeed(uint8_t byte) {
     switch(byte & 0x0F) {

diff --git a/cores/esp8266/Updater.cpp b/cores/esp8266/Updater.cpp
@@ -68,8 +68,10 @@ void UpdaterClass::_reset() {
 }
 
 bool UpdaterClass::begin(size_t size, int command, int ledPin, uint8_t ledOn) {
+#ifdef ERASE_CONFIG_H
   // Empty call so erase_config.cpp module to ensure it is built and linked in.
   enable_erase_config_at_link_time();
+#endif
 
   if(_size > 0){
 #ifdef DEBUG_UPDATER

diff --git a/cores/esp8266/core_esp8266_main.cpp b/cores/esp8266/core_esp8266_main.cpp
@@ -282,7 +282,7 @@ void init_done() {
    https://github.com/esp8266/Arduino/pull/4889
 
 */
-#if defined(ERASE_CONFIG_H)
+#if defined(DEBUG_ERASE_CONFIG)
 extern "C" void fix_divider(void);
 #define FIX_DIVIDER fix_divider
 #define ETS_PRINTF(...) ets_uart_printf(__VA_ARGS__)
@@ -325,7 +325,7 @@ extern "C" void user_init(void) {
     struct rst_info *rtc_info_ptr = system_get_rst_info();
     memcpy((void *) &resetInfo, (void *) rtc_info_ptr, sizeof(resetInfo));
 
-#if defined(ERASE_CONFIG_H)
+#if defined(DEBUG_ERASE_CONFIG)
     uart_div_modify(0, UART_CLK_FREQ / (74880));
     ETS_DELAY_US(150);
     ETS_PRINTF("\nuser_init()\n");