If it is set to Level 1 or Level 2, change it back to (Disabled).
esptool.py itself has --before default_reset and --after hard_reset . But for hard lock, use:
If your code turns off SWD pins or puts the chip into low-power Standby/Shutdown mode, add a delay(5000); at the very beginning of your main() function. This gives your programmer a 5-second window to halt the chip before it locks itself out. writing flash programmer... fail unlock tool
If using an MTK tool, look for a custom Download Agent ( .bin file) specific to your exact phone model rather than using the tool's default file.
[Unlock Tool / PC] ---> [BootROM Mode / EDL] ---> [Loads Flash Programmer into RAM] ---> [Unlocks / Writes Flash Memory] If it is set to Level 1 or
A surprisingly common cause of failure is a simple omission: many unlock tools require a specific sequence that includes a full power cycle of the target device. For example, with some STM32 devices and the J-Link tool, a command like Target -> unsercure chip must be followed by an , not just a system reset pulse. Failing to do this leaves the register locked and the flash protection active.
If power is lost or the reset button is pressed while the chip is erasing a flash sector, the data left behind may be a mix of 0 s and 1 s. Worse, it can scramble the Option Bytes or Security passwords. This often results in a permanently locked device if the sector contains the security configuration. For devices like TI C2000, resetting during an erase that zeros out the password location makes the chip unrecoverable via standard means. This gives your programmer a 5-second window to
The failure of a writing flash programmer and its associated unlock tool is a rite of passage in embedded engineering. It is a challenge that sits at the intersection of software, hardware, and security. While often terrifying in the moment, it is almost always solvable through a systematic approach: isolating the cause, trying the appropriate software tools, and, when necessary, bypassing the processor to access the memory directly.