Add mcu/*stm32l4.

mcu/sys-stm32l4.h

@@ -0,0 +1,33 @@
+#define BOARD_ID_ST_NUCLEO_L432    0x3a8d5116
+
+extern const uint8_t sys_version[8];
+#if defined(USE_SYS3) || defined(USE_SYS_BOARD_ID)
+extern const uint32_t sys_board_id;
+extern const uint8_t sys_board_name[];
+# define SYS_BOARD_ID sys_board_id
+#else
+# define SYS_BOARD_ID BOARD_ID
+#endif
+
+/* XXX: unique_device_id */
+
+void set_led (int on);
+
+uintptr_t flash_init (const char *f_name);
+void flash_unlock (void);
+int flash_program_halfword (uintptr_t addr, uint16_t data);
+int flash_erase_page (uintptr_t addr);
+int flash_check_blank (const uint8_t *p_start, size_t size);
+int flash_write (uintptr_t dst_addr, const uint8_t *src, size_t len);
+int flash_protect (void);
+void __attribute__((noreturn))
+flash_erase_all_and_exec (void (*entry)(void));
+
+void usb_lld_sys_init (void);
+void usb_lld_sys_shutdown (void);
+
+void __attribute__((noreturn))
+nvic_system_reset (void);
+
+void clock_init (void);
+void gpio_init (void);