bootm03x

Bootloader for Nuvoton M03x microcontrollers (M031 and M032).

• Nuvoton M031 Series BSP

• NuEclipse IDE

• NuLink Command Tool

Usage

The Nuvoton M031/032 MCU has can boot either from APROM (address 0x0) or LDROM (address 0x100000).

This bootloader is intended to be used with an application that normally boots from APROM.

For bootloader operation , the APROM memory is splitted in two parts of equal length (MEM_LEN, which is half of total APROM size). The first part is the main region, from which the main program runs. The second part is the transfer region, used only for keeping the new firmware data during boot loading.

Flash size	MEM_LEN
16K	0x2000
32K	0x4000
64K	0x8000
128K	0x10000
256K	0x20000
512K	0x40000

The MEM_LEN must be stored in the APROM main region 0x218 fixed address, so the bootloader can know where to erase and fro where to copy data.

The resulting binary from this program need to be flashed at the LDROM address (0x100000). Flashing can be done with the following command lines:

1. Convert Intel HEX files to binary using hex2bin:

   hex2bin -e bin bootm03x.hex
   hex2bin -e bin application.hex

2. Erase flash:

   NuLink -e all

3. Write firmware binaries in the specific regions:

   NuLink -w APROM application.bin
   NuLink -w LDROM bootm03x.bin

4. Write CONFIG data to set default boot from APROM:

   NuLink -w CFG0 0xFFFFFFBF
   NuLink -w CFG1 0xFFFFFFFF
   NuLink -w CFG2 0xFFFFFF5A
   NuLink -w CFG3 0xFFFFFFFF

5. Reset the MCU

   NuLink -reset

Operation

• MCU boots from APROM by default, and the application keeps running;
• Application receives new firmware data and stores it at the transfer region starting from address MEM_LEN;
• Application gets the new firmware data length. This value is stored at the fixed address FW_LEN = MEM_LEN + 0x214;
• Application checks the new firmware data integrity (CRC32 calculation of FW_LEN starting from MEM_LEN address);
• Application sets the default boot to LDROM;
• Bootloader runs and performs as described in the following flowchart:

Changelog

v2.0

• Initial version.