sysparam fixes, tests, spi flash refactoring (#299)

Original work by @ourairquality
* Sysparam threadsafe and SPI access
* Sysparam test cases
* Fix for negative int8
* Sysparam getting bool without memory allocation. Bool tests.
* SPI flash refactoring.
* Extract common spiflash.c into core.
* Use spiflash.c in sysparam.
* Use memcpy in spiflash.c insted of hand-written version.
* Tests for spiflash.c

core/include/spiflash.h

@@ -0,0 +1,64 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 sheinz (https://github.com/sheinz)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef __SPIFLASH_H__
+#define __SPIFLASH_H__
+
+#include <stdint.h>
+#include <stdbool.h>
+#include "common_macros.h"
+
+#define SPI_FLASH_SECTOR_SIZE      4096
+
+/**
+ * Read data from SPI flash.
+ *
+ * @param addr Address to read from. Can be not aligned.
+ * @param buf Buffer to read to. Doesn't have to be aligned.
+ * @param size Size of data to read. Buffer size must be >= than data size.
+ *
+ * @return true if success, otherwise false
+ */
+bool IRAM spiflash_read(uint32_t addr, uint8_t *buf, uint32_t size);
+
+/**
+ * Write data to SPI flash.
+ *
+ * @param addr Address to write to. Can be not aligned.
+ * @param buf Buffer of data to write to flash. Doesn't have to be aligned.
+ * @param size Size of data to write. Buffer size must be >= than data size.
+ *
+ * @return true if success, otherwise false
+ */
+bool IRAM spiflash_write(uint32_t addr, uint8_t *buf, uint32_t size);
+
+/**
+ * Erase a sector.
+ *
+ * @param addr Address of sector to erase. Must be sector aligned.
+ *
+ * @return true if success, otherwise false
+ */
+bool IRAM spiflash_erase_sector(uint32_t addr);
+
+#endif  // __SPIFLASH_H__