CURRENT.UF2 always blank

[zvecr]

Operating System

Windows 11
Fedora 38
Arch

INFO_UF2.TXT

TinyUF2 Bootloader 0.14.0-10-g86a054f - st/cmsis_device_f3 (v2.3.6) st/stm32f3xx_hal_driver (v1.5.6-9-g75cf4fc) tinyusb (0.15.0-331-ge3b3229d6)
Model: ST STM32F303 Discovery
Board-ID: STM32F303 discovery
Date: Jun 5 2023

What happened ?

Content of CURRENT.UF2 is always just zeros, and does not reflect the current flash contents,

hexdump ~/Desktop/CURRENT.UF2
0000000 0000 0000 0000 0000 0000 0000 0000 0000
*
0080000

(Where hexdump truncates identical lines as *)

This has been reproduced on both a STM32F303 discovery and stm32f401_blackpill, so the issue is not isolated to a single port.

How to reproduce ?

Reboot to bootloader
Copy .uf2 to device
Reboot to bootloader again
Copy CURRENT.UF2 to host
Inspect content

Debug Log

No response

Screenshots

No response

[MiyukiDark]

This issue will be on all MCUs where the flash did not start at address 0
It just calculates it totally wrong
The issue is in ghostfat.c on lines 486 and on

// CURRENT.UF2: generate data on-the-fly
      uint32_t addr = BOARD_FLASH_APP_START + (fileRelativeSector * UF2_FIRMWARE_BYTES_PER_SECTOR);
      if ( addr < _flash_size ) // TODO abstract this out
      {

addr is always bigger than the size of a flash

[hathach]

should be fixed by #367, pleaes check it out