Add support for onboard SPI flash

bdev.c

@@ -0,0 +1,24 @@
+#include "storage.h"
+
+// External SPI flash uses standard SPI interface
+
+STATIC const mp_soft_spi_obj_t soft_spi_bus = {
+    .delay_half = MICROPY_HW_SOFTSPI_MIN_DELAY,
+    .polarity = 0,
+    .phase = 0,
+    .sck = MICROPY_HW_SPIFLASH_SCK,
+    .mosi = MICROPY_HW_SPIFLASH_MOSI,
+    .miso = MICROPY_HW_SPIFLASH_MISO,
+};
+
+STATIC mp_spiflash_cache_t spi_bdev_cache;
+
+const mp_spiflash_config_t spiflash_config = {
+    .bus_kind = MP_SPIFLASH_BUS_SPI,
+    .bus.u_spi.cs = MICROPY_HW_SPIFLASH_CS,
+    .bus.u_spi.data = (void*)&soft_spi_bus,
+    .bus.u_spi.proto = &mp_soft_spi_proto,
+    .cache = &spi_bdev_cache,
+};
+
+spi_bdev_t spi_bdev;

board_init.c

@@ -0,0 +1,7 @@
+#include "py/mphal.h"
+
+void Black_F407ZG_board_early_init(void) {
+    // set SPI flash CS pin high
+    mp_hal_pin_output(pin_B14);
+    mp_hal_pin_write(pin_B14, 1);
+}

mpconfigboard.h

@@ -1,5 +1,10 @@
 #define MICROPY_HW_BOARD_NAME       "MCUDEV STM32F407ZG"
 #define MICROPY_HW_MCU_NAME         "STM32F407ZG"
+#define MICROPY_HW_FLASH_FS_LABEL   "BlackF407ZG"
+
+// 1 = use internal flash (1024 KByte)
+// 0 = use onboard SPI flash (2 MByte) Winbond W25Q16
+#define MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE (1)
 
 #define MICROPY_HW_HAS_SWITCH       (1)		// has 2 buttons KEY0=PE4, KEY1=PE3
 #define MICROPY_HW_HAS_FLASH        (1)
@@ -127,6 +132,31 @@
 #define MICROPY_HW_LED_ON(pin)      (mp_hal_pin_low(pin))
 #define MICROPY_HW_LED_OFF(pin)     (mp_hal_pin_high(pin))
 
+// If using onboard SPI flash
+#if !MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE
+
+// Winbond W25Q16 SPI Flash = 16 Mbit (2 MByte)
+#define MICROPY_HW_SPIFLASH_SIZE_BITS (16 * 1024 * 1024)
+#define MICROPY_HW_SPIFLASH_CS      (pin_B14)
+#define MICROPY_HW_SPIFLASH_SCK     (pin_B3)
+#define MICROPY_HW_SPIFLASH_MISO    (pin_B4)
+#define MICROPY_HW_SPIFLASH_MOSI    (pin_B5)
+
+#define MICROPY_BOARD_EARLY_INIT    Black_F407ZG_board_early_init
+void Black_F407ZG_board_early_init(void);
+
+extern const struct _mp_spiflash_config_t spiflash_config;
+extern struct _spi_bdev_t spi_bdev;
+#define MICROPY_HW_BDEV_IOCTL(op, arg) ( \
+    (op) == BDEV_IOCTL_NUM_BLOCKS ? (MICROPY_HW_SPIFLASH_SIZE_BITS / 8 / FLASH_BLOCK_SIZE) : \
+    (op) == BDEV_IOCTL_INIT ? spi_bdev_ioctl(&spi_bdev, (op), (uint32_t)&spiflash_config) : \
+    spi_bdev_ioctl(&spi_bdev, (op), (arg)) \
+)
+#define MICROPY_HW_BDEV_READBLOCKS(dest, bl, n) spi_bdev_readblocks(&spi_bdev, (dest), (bl), (n))
+#define MICROPY_HW_BDEV_WRITEBLOCKS(src, bl, n) spi_bdev_writeblocks(&spi_bdev, (src), (bl), (n))
+
+#endif
+
 // SD card detect switch
 //	#define MICROPY_HW_SDCARD_DETECT_PIN        (pin_A8)	// nope
 //	#define MICROPY_HW_SDCARD_DETECT_PULL       (GPIO_PULLUP)