stmhal: Add support for flash filesystem on F401 MCUs.

It uses a 16k cache buffer and so the filesystem size is limited.

stmhal/flash.c

@@ -37,10 +37,12 @@
 #define ADDR_FLASH_SECTOR_5     ((uint32_t)0x08020000) /* Base @ of Sector 5, 128 Kbytes */
 #define ADDR_FLASH_SECTOR_6     ((uint32_t)0x08040000) /* Base @ of Sector 6, 128 Kbytes */
 #define ADDR_FLASH_SECTOR_7     ((uint32_t)0x08060000) /* Base @ of Sector 7, 128 Kbytes */
+#if defined(FLASH_SECTOR_8)
 #define ADDR_FLASH_SECTOR_8     ((uint32_t)0x08080000) /* Base @ of Sector 8, 128 Kbytes */
 #define ADDR_FLASH_SECTOR_9     ((uint32_t)0x080A0000) /* Base @ of Sector 9, 128 Kbytes */
 #define ADDR_FLASH_SECTOR_10    ((uint32_t)0x080C0000) /* Base @ of Sector 10, 128 Kbytes */
 #define ADDR_FLASH_SECTOR_11    ((uint32_t)0x080E0000) /* Base @ of Sector 11, 128 Kbytes */
+#endif
 
 static const uint32_t flash_info_table[26] = {
     ADDR_FLASH_SECTOR_0, FLASH_SECTOR_0,
@@ -51,11 +53,15 @@ static const uint32_t flash_info_table[26] = {
     ADDR_FLASH_SECTOR_5, FLASH_SECTOR_5,
     ADDR_FLASH_SECTOR_6, FLASH_SECTOR_6,
     ADDR_FLASH_SECTOR_7, FLASH_SECTOR_7,
+    #if defined(FLASH_SECTOR_8)
     ADDR_FLASH_SECTOR_8, FLASH_SECTOR_8,
     ADDR_FLASH_SECTOR_9, FLASH_SECTOR_9,
     ADDR_FLASH_SECTOR_10, FLASH_SECTOR_10,
     ADDR_FLASH_SECTOR_11, FLASH_SECTOR_11,
     ADDR_FLASH_SECTOR_11 + 0x20000, 0,
+    #else
+    ADDR_FLASH_SECTOR_7 + 0x20000, 0,
+    #endif
 };
 
 uint32_t flash_get_sector_info(uint32_t addr, uint32_t *start_addr, uint32_t *size) {

stmhal/storage.c

@@ -34,10 +34,26 @@
 #include "flash.h"
 #include "storage.h"
 
+#if defined(STM32F405xx)
+
 #define CACHE_MEM_START_ADDR (0x10000000) // CCM data RAM, 64k
 #define FLASH_PART1_START_BLOCK (0x100)
 #define FLASH_PART1_NUM_BLOCKS (224) // 16k+16k+16k+64k=112k
 #define FLASH_MEM_START_ADDR (0x08004000) // sector 1, 16k
+#define FLASH_SECTOR_SIZE_MAX (0x10000) // 64k max, size of CCM
+
+#elif defined(STM32F401xE)
+
+STATIC byte flash_cache_mem[0x4000] __attribute__((aligned(4))); // 16k
+#define CACHE_MEM_START_ADDR (&flash_cache_mem[0])
+#define FLASH_PART1_START_BLOCK (0x100)
+#define FLASH_PART1_NUM_BLOCKS (128) // 16k+16k+16k+16k(of64k)=64k
+#define FLASH_MEM_START_ADDR (0x08004000) // sector 1, 16k
+#define FLASH_SECTOR_SIZE_MAX (0x4000) // 16k max due to size of cache buffer
+
+#else
+#error "no storage support for this MCU"
+#endif
 
 #define FLASH_FLAG_DIRTY        (1)
 #define FLASH_FLAG_FORCE_WRITE  (2)
@@ -62,6 +78,9 @@ static uint8_t *flash_cache_get_addr_for_write(uint32_t flash_addr) {
     uint32_t flash_sector_start;
     uint32_t flash_sector_size;
     uint32_t flash_sector_id = flash_get_sector_info(flash_addr, &flash_sector_start, &flash_sector_size);
+    if (flash_sector_size > FLASH_SECTOR_SIZE_MAX) {
+        flash_sector_size = FLASH_SECTOR_SIZE_MAX;
+    }
     if (flash_cache_sector_id != flash_sector_id) {
         flash_cache_flush();
         memcpy((void*)CACHE_MEM_START_ADDR, (const void*)flash_sector_start, flash_sector_size);