adafruit-mirror/Adafruit_Learning_System_Guides
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
Adafruit_Learning_System_Gu.../uf2_flash_erasers
History
Dan Halbert b7c80d7a59 uf2_flash_erasers: fix erroneous erase_m0.uf2 
However, note that the UF2 bootloader on Metro M4 right now can only write the first 256kB of flash.
So don't advertise erase_m4.uf2 for the M4 yet.
2017-11-09 20:44:02 -05:00
..
erase_m0.uf2 uf2_flash_erasers: fix erroneous erase_m0.uf2 2017-11-09 20:44:02 -05:00
erase_m4.uf2 Add uf2_flash_erasers for conveniently erasing M0 and M4 boards. 2017-11-08 14:11:28 -05:00
README.md Add uf2_flash_erasers for conveniently erasing M0 and M4 boards. 2017-11-08 14:11:28 -05:00

README.md

These UF2 files load all zeros into all of flash, skipping the bootloader section.

  • erase_m0.uf2 writes 256k-8k of zeros starting at 8k
  • erase_m4.uf2 writes 512k-16k of zeros starting at 16k

These are useful for clearing out damaged CIRCUITPY filesystems in internal flash.

Example of how to create erase-m4.uf2, which assume 512k of flash and a 16k bootloader:

$ truncate -s 507904 512k-16k.bin   # 507904 is 512k minus 16k
$ circuitpython/tools/uf2/utils/uf2conv.py -c -b 16384 512k-16k.bin -o 512k-16k.uf2
$ mv 512k-16k.uf2 erase-m4.uf2

These don't erase CIRCUITPY in SPI flash, such as on Express boards. For flash erasers for SPI flash, see https://github.com/adafruit/Adafruit_SPIFlash/tree/master/examples/flash_erase_express.