SAME54BOOT

A serial and secure programming tool for SAME54 series microcontroller.

Boot Scheme

Boot Process

Software Satck

Memory Layout

Communication handshake

Program the firmware image to the internal flash in MCU.

Program the firmware image to the external SPI NOR flash manage by LittleFS.

Communication command

/* bootprotocol commands */
// The control commands
#define CMD_CHK_PROTOCOL            0x01
#define CMD_CHK_DEVICE              0x02
#define CMD_PROG_END                0x03
#define CMD_PROG_EXT_FLASH_BOOT     0x04

// The internal flash associated commands
#define CMD_FLASH_SET_PGSZ          0x10
#define CMD_FLASH_GET_PGSZ          0x11
#define CMD_FLASH_WRITE             0x12
#define CMD_FLASH_READ              0x13
#define CMD_FLASH_VERIFY            0x14
#define CMD_FLASH_ERASE_SECTOR      0x15
#define CMD_FLASH_ERASE_ALL         0x16

// The EEPROM associated commands
#define CMD_EEPROM_SET_PGSZ         0x20
#define CMD_EEPROM_GET_PGSZ         0x21
#define CMD_EEPROM_WRITE            0x22
#define CMD_EEPROM_READ             0x23
#define CMD_EEPROM_VERIFY           0x24
#define CMD_EEPROM_ERASE_SECTOR     0x25
#define CMD_EEPROM_ERASE_ALL        0x26

// The external flash (SPI NOR flash) associated commands
#define CMD_EXT_FLASH_FOPEN         0x30
#define CMD_EXT_FLASH_FCLOSE        0x31
#define CMD_EXT_FLASH_WRITE         0x32
#define CMD_EXT_FLASH_READ          0x33
#define CMD_EXT_FLASH_VERIFY        0x34
#define CMD_EXT_FLASH_ERASE_SECTOR  0x35
#define CMD_EXT_FLASH_HEX_DEL       0x36

Flowchart

Bootloader packet format

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     HEADER                    |    COMMAND    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|            LENGTH             |                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +
|                                                               |
+                                                               +
|                     DATA (variable length)                    |
+                                               +-+-+-+-+-+-+-+-+
|                                               |    CHECKSUM   |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

• HEADER : 0xA5A5A5
• COMMAND : See details in the previous intruduction
• LENGTH : Data length
• DATA : Variable length
• CHECKSUM : sum(data) % 255

Bootloader data format

HOST Tool

ref: https://github.com/cy023/SerProg