-void eeprom_read_buf(uint8_t *buf, uint32_t addr, uint8_t count);
-void ram_read_buf(uint8_t *buf, uint32_t addr, uint8_t count);
-void flash_read_buf(uint8_t *buf, uint32_t addr, uint8_t count);
+ERRNUM eeprom_read_buf(uint8_t *buf, uint32_t addr, uint8_t count);
+ERRNUM ram_read_buf(uint8_t *buf, uint32_t addr, uint8_t count);
+ERRNUM flash_read_buf(uint8_t *buf, uint32_t addr, uint8_t count);