UF2 bootloader for CH32V2xx / CH32V3xx

dcexpert

UF2 bootloader for CH32V2xx / CH32V3xx [Copy link]

UF2 bootloader for WCH RISC-V microcontrollers. This allows updating the program by dragging the file to a virtual USB mass storage device, no special software is required.

Instructions

• Triggered by double-clicking the reset button within 0.5 seconds
• Need to use R16BKP_DATAR10
  • Write 0x4170 ('Ap') to boot immediately into the application without delay
  • Write 0x624c ('bL') to unconditionally enter the bootloader
• Suitable for 4096 bytes
• Tested and built with MounRiver GCC V1.91
  • Improve code size by using "XW" instructions that are not upstream
• Only USBD peripherals are supported (i.e. no USBFS support)
  • USBD and USBFS are completely different. The QFN28 package (the largest number on LCSC) only combines USBD
  • Note that if using the official devkit's USBD you will need a USB aa cable
• Internal 8 MHz oscillator (although there are stability issues)
  • The tolerance of the HSI oscillator (-1.0% to +1.6%) is well outside the specified range for USB full speed ($\pm$0.25%), but it seems to work in practice
  • The ISP ROM bootloader also does this
• Should work for most CH32V2xx and CH32V3xx families with appropriate changes to the hard coded constants.
• Allows downloading to flash and SRAM with the "non-primary flash" flag (this is how the RP2040 bootrom works)
  • The Flash download address must be 08xxxxxx (not starting from 0)
  • The SRAM download address must be 20xxxxxx
  • The entire size of the SRAM can be used because the USBD contains a buffer memory independent of the main SRAM
• Automatic restart after download is complete, but this only works if the download is small enough. Larger downloads will still update but will not trigger an automatic restart and will require a manual restart.

链接已隐藏，如需查看请登录或者注册

freebsder

What is UF2?

dcexpert

freebsder posted on 2024-5-17 17:25 What is UF2?

The bootloader format released by Microsoft uses a disk to update the program.

lugl4313820

This is very cool to use and solves a big file problem.

freebsder

dcexpert posted on 2024-5-17 20:00 The bootloader format released by Microsoft uses the disk method to update the program.

Disk mode? Is it similar to mbr?

fxyc87

I also used uf2 to update the firmware of my GD32F303, which is more convenient and can solve the USB flash drive update problem without FATFS.

dcexpert

fxyc87 posted on 2024-5-28 12:27 I also used uf2 to update the firmware of my GD32F303, which is more convenient and can solve the USB flash drive update problem without FATFS.