This a in-application programming (IAP) bootloader

Supported feature

• Upgrade firmware from sd card
• Use usb-ttl to show log

Step

Ready

• A fat32 card (only sdhc card)
• Rename your firmware to firmware.bin (the format is bin not elf)
• Copy your firmware to the card's root
• Insert card

Power Up Board

• Check the bootloader works well (green LED light)
• Auto upgrade if card has install file in the root
• OR press KEY0 to upgrade (green LED dark and red LED light)
• Wait

Attentions

Partition information

• Bootloader: 0x08000000 to 0x0801FFFF (128KB)
• Firmware: 0x08020000 to 0x080FFFFF (896KB; Sector from 5 to 11)

USB-TTL (CH340)

• Baudrare: 115200
• Data Bits: 8
• Parity: none
• Stop Bits: 1

How to turn elf to bin

arm-none-eabi-objcopy -O binary target/thumbv7m-none-eabi/debug/xxxx firmware.bin

Console log

This is a IAP bootloader
start to check for upgrade from sd card

found firmware
if you do nothing, it will boot os in 5 seconds
if you want to upgrade, press the KEY0

upgrading
start to erase flash, it will take minutes
erase flash successfully
start to upgrade firmware
upgrade successfully

boot os

Download

• Download artifacts from Actions

Relevant Project

• sdio_sdhc
• fat32