esp32_flasher: Adds proper SPI flash state backup and restoration

Author: gerekon

contrib/loaders/flash/esp32/esp32_stub_flasher.h

@@ -0,0 +1,26 @@
+/***************************************************************************
+ *   ESP xtensa chips flasher stub definitions                             *
+ *   Copyright (C) 2019 Espressif Systems Ltd.                             *
+ *   Author: Alexey Gerenkov <[email protected]>                        *
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program 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 General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
+ ***************************************************************************/
+#ifndef ESP32_FLASHER_STUB_H
+#define ESP32_FLASHER_STUB_H
+
+#define ESP32_FLASH_SECTOR_SIZE 4096
+
+#endif //ESP32_FLASHER_STUB_H