esptool can access chip but can't access flash memory from a ESP32-U4WD (ESPTOOL-1372)

[aanban]

Operating System

Linux 7.1.8-1-cachyos

Esptool Version

v5.3.1

Python Version

3.13.11

Chip Description

ESP32-U4WDH (revision v3.1)

Device Description

Shelly plus 1 device with this ESP32 chip

Hardware Configuration

• Shelly plus 1 device
• Waveshare FT232 USB converter
• Button for GPIO0

How is Esptool Run

within a linux terminal

Full Esptool Command Line that Was Run

esptool --port /dev/ttyUSB0 --chip esp32 flash-id

Esptool Output

esptool v5.3.1
Connected to ESP32 on /dev/ttyUSB0:
Chip type:          ESP32-U4WDH (revision v3.1)
Features:           Wi-Fi, BT, Dual Core + LP Core, 240MHz, Embedded Flash, Vref calibration in eFuse, Coding Scheme None
Crystal frequency:  40MHz
MAC:                a0:a3:b3:dc:ba:18

Stub flasher is already running. No upload is necessary.

Warning: Failed to communicate with the flash chip, read/write operations will fail. Try checking the chip connections or removing any other hardware connected to IOs.
Flash Memory Information:
=========================
Manufacturer: ff
Device: ffff
Detected flash size: Unknown
Flash voltage set by a strapping pin: 3.3V

Hard resetting via RTS pin...



output with --trace:

esptool v5.3.1
Serial port /dev/ttyUSB0:
Connecting...
  TRACE +0.000   --- Cmd SYNC (0x08) | data_len 36 | wait_response 1 | timeout 0.100 | data 
    0707122055555555 5555555555555555 | ... UUUUUUUUUUUU
    5555555555555555 5555555555555555 | UUUUUUUUUUUUUUUU
    55555555                          | UUUU ---
  TRACE +0.000   Write 46 bytes:       
    c000082400000000 0007071220555555 | ...$........ UUU
    5555555555555555 5555555555555555 | UUUUUUUUUUUUUUUU
    5555555555555555 5555555555c0     | UUUUUUUUUUUUU.
  TRACE +0.027   Read 1 bytes:         c0
  TRACE +0.000   Read 95 bytes:        
    0108020000000000 0000c0c001080200 | ................
    000000000000c0c0 0108020000000000 | ................
    0000c0c001080200 000000000000c0c0 | ................
    0108020000000000 0000c0c001080200 | ................
    000000000000c0c0 0108020000000000 | ................
    0000c0c001080200 000000000000c0   | ...............
  TRACE +0.000   Received full packet: 01080200000000000000
  TRACE +0.000   Received full packet: 01080200000000000000
  TRACE +0.000   Received full packet: 01080200000000000000
  TRACE +0.000   Received full packet: 01080200000000000000
  TRACE +0.000   Received full packet: 01080200000000000000
  TRACE +0.000   Received full packet: 01080200000000000000
  TRACE +0.000   Received full packet: 01080200000000000000
  TRACE +0.000   Received full packet: 01080200000000000000

Detecting chip type...
  TRACE +0.000   --- Cmd GET_SECURITY_INFO (0x14) | data_len 0 | wait_response 1 | timeout 3.000 | data  ---
  TRACE +0.000   Write 10 bytes:       c00014000000000000c0
  TRACE +0.015   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        0114020000000000ff00c0
  TRACE +0.000   Received full packet: 0114020000000000ff00

  TRACE +0.000   --- Cmd GET_SECURITY_INFO (0x14) | data_len 0 | wait_response 1 | timeout 3.000 | data  ---
  TRACE +0.000   Write 10 bytes:       c00014000000000000c0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        0114020000000000ff00c0
  TRACE +0.000   Received full packet: 0114020000000000ff00

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 00100040 ---
  TRACE +0.000   Write 14 bytes:       c0000a04000000000000100040c0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200831df0000000c0
  TRACE +0.000   Received full packet: 010a0200831df0000000
 ESP32
Connected to ESP32 on /dev/ttyUSB0:

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 0ca0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000000ca0f53fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200b0a800000000c0
  TRACE +0.000   Received full packet: 010a0200b0a800000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 0ca0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000000ca0f53fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200b0a800000000c0
  TRACE +0.000   Received full packet: 010a0200b0a800000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 14a0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a04000000000014a0f53fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200262218010000c0
  TRACE +0.000   Received full packet: 010a0200262218010000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 7c60f63f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000007c60f63fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200002004960000c0
  TRACE +0.000   Received full packet: 010a0200002004960000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 14a0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a04000000000014a0f53fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200262218010000c0
  TRACE +0.000   Received full packet: 010a0200262218010000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 0ca0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000000ca0f53fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200b0a800000000c0
  TRACE +0.000   Received full packet: 010a0200b0a800000000
Chip type:          ESP32-U4WDH (revision v3.1)

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 0ca0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000000ca0f53fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200b0a800000000c0
  TRACE +0.000   Received full packet: 010a0200b0a800000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 0ca0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000000ca0f53fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200b0a800000000c0
  TRACE +0.000   Received full packet: 010a0200b0a800000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 10a0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a04000000000010a0f53fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200320500000000c0
  TRACE +0.000   Received full packet: 010a0200320500000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 18a0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a04000000000018a0f53fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200040000000000c0
  TRACE +0.000   Received full packet: 010a0200040000000000
Features:           Wi-Fi, BT, Dual Core + LP Core, 240MHz, Embedded Flash, Vref calibration in eFuse, Coding Scheme None

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 1400f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000001400f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a02005f0180000000c0
  TRACE +0.000   Received full packet: 010a02005f0180000000
Crystal frequency:  40MHz

  TRACE +0.003   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 08a0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a04000000000008a0f53fc0
  TRACE +0.013   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200a3a020000000c0
  TRACE +0.000   Received full packet: 010a0200a3a020000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 04a0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a04000000000004a0f53fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a020018badcb30000c0
  TRACE +0.000   Received full packet: 010a020018badcb30000
MAC:                a0:a3:b3:dc:ba:18

Stub flasher is already running. No upload is necessary.


  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 1c20f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000001c20f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200400000800000c0
  TRACE +0.000   Received full packet: 010a0200400000800000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 2420f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000002420f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000700000c0
  TRACE +0.000   Received full packet: 010a0200000000700000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2c20f43f17000000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002c20f43f170000 | ........., .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f00000090ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f000000 | .......... .?...
    90ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f9f000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f9f0000 | .........$ .?...
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 8020f43f00000000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 008020f43f000000 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 0020f43f00000400ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 000020f43f000004 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 0020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000000020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000000000c0
  TRACE +0.000   Received full packet: 010a0200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 8020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000008020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200ffffff000000c0
  TRACE +0.000   Received full packet: 010a0200ffffff000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f40000080ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f400000 | .......... .?@..
    80ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f00000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f000000 | .........$ .?...
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 1c20f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000001c20f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200400000800000c0
  TRACE +0.000   Received full packet: 010a0200400000800000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 2420f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000002420f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000700000c0
  TRACE +0.000   Received full packet: 010a0200000000700000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2c20f43f07000000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002c20f43f070000 | ........., .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2020f43f0700005cffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002020f43f070000 | .........  .?...
    5cffffffff000000 00c0             | \.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f000000f0ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f000000 | .......... .?...
    f0ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f5a000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f5a0000 | .........$ .?Z..
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 0420f43f00100000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 000420f43f001000 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 8020f43f00000000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 008020f43f000000 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 0020f43f00000400ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 000020f43f000004 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 0020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000000020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000000000c0
  TRACE +0.000   Received full packet: 010a0200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 8020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000008020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200ff0000000000c0
  TRACE +0.000   Received full packet: 010a0200ff0000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f40000080ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f400000 | .......... .?@..
    80ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f00000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f000000 | .........$ .?...
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 1c20f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000001c20f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200400000800000c0
  TRACE +0.000   Received full packet: 010a0200400000800000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 2420f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000002420f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000700000c0
  TRACE +0.000   Received full packet: 010a0200000000700000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2c20f43f1f000000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002c20f43f1f0000 | ........., .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2020f43f0700005cffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002020f43f070000 | .........  .?...
    5cffffffff000000 00c0             | \.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f000000f0ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f000000 | .......... .?...
    f0ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f5a000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f5a0000 | .........$ .?Z..
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 0420f43f00000000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 000420f43f000000 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 8020f43f00000000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 008020f43f000000 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 0020f43f00000400ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 000020f43f000004 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 0020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000000020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000000000c0
  TRACE +0.000   Received full packet: 010a0200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 8020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000008020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200ffffffff0000c0
  TRACE +0.000   Received full packet: 010a0200ffffffff0000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f40000080ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f400000 | .......... .?@..
    80ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f00000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f000000 | .........$ .?...
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 1c20f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000001c20f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200400000800000c0
  TRACE +0.000   Received full packet: 010a0200400000800000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 2420f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000002420f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000700000c0
  TRACE +0.000   Received full packet: 010a0200000000700000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2c20f43f17000000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002c20f43f170000 | ........., .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f00000090ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f000000 | .......... .?...
    90ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f9f000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f9f0000 | .........$ .?...
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 8020f43f00000000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 008020f43f000000 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 0020f43f00000400ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 000020f43f000004 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 0020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000000020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000000000c0
  TRACE +0.000   Received full packet: 010a0200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 8020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000008020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200ffffff000000c0
  TRACE +0.000   Received full packet: 010a0200ffffff000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f40000080ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f400000 | .......... .?@..
    80ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f00000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f000000 | .........$ .?...
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000
Warning: Failed to communicate with the flash chip, read/write operations will fail. Try checking the chip connections or removing any other hardware connected to IOs.

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 1c20f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000001c20f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200400000800000c0
  TRACE +0.000   Received full packet: 010a0200400000800000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 2420f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000002420f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000700000c0
  TRACE +0.000   Received full packet: 010a0200000000700000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f00000080ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f000000 | .......... .?...
    80ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f66000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f660000 | .........$ .?f..
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 8020f43f00000000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 008020f43f000000 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.015   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 0020f43f00000400ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 000020f43f000004 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 0020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000000020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000000000c0
  TRACE +0.000   Received full packet: 010a0200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 8020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000008020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000000000c0
  TRACE +0.000   Received full packet: 010a0200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f40000080ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f400000 | .......... .?@..
    80ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f00000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f000000 | .........$ .?...
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 1c20f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000001c20f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200400000800000c0
  TRACE +0.000   Received full packet: 010a0200400000800000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 2420f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000002420f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000700000c0
  TRACE +0.000   Received full packet: 010a0200000000700000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f00000080ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f000000 | .......... .?...
    80ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f99000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f990000 | .........$ .?...
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 8020f43f00000000ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 008020f43f000000 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 0020f43f00000400ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 000020f43f000004 | .......... .?...
    00ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 0020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000000020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000000000c0
  TRACE +0.000   Received full packet: 010a0200000000000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 8020f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000008020f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200000000000000c0
  TRACE +0.000   Received full packet: 010a0200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 1c20f43f40000080ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 001c20f43f400000 | .......... .?@..
    80ffffffff000000 00c0             | ..........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000

  TRACE +0.000   --- Cmd WRITE_REG (0x09) | data_len 16 | wait_response 1 | timeout 3.000 | data 2420f43f00000070ffffffff00000000 ---
  TRACE +0.000   Write 26 bytes:       
    c000091000000000 002420f43f000000 | .........$ .?...
    70ffffffff000000 00c0             | p.........
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        01090200000000000000c0
  TRACE +0.000   Received full packet: 01090200000000000000
Flash Memory Information:
=========================
Manufacturer: ff
Device: ffff
Detected flash size: Unknown

  TRACE +0.001   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 7480f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000007480f43fc0
  TRACE +0.015   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a02000000a0020000c0
  TRACE +0.000   Received full packet: 010a02000000a0020000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 10a0f53f ---
  TRACE +0.000   Write 14 bytes:       c0000a04000000000010a0f53fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200320500000000c0
  TRACE +0.000   Received full packet: 010a0200320500000000

  TRACE +0.000   --- Cmd READ_REG (0x0a) | data_len 4 | wait_response 1 | timeout 3.000 | data 3840f43f ---
  TRACE +0.000   Write 14 bytes:       c0000a0400000000003840f43fc0
  TRACE +0.016   Read 1 bytes:         c0
  TRACE +0.000   Read 11 bytes:        010a0200030000000000c0
  TRACE +0.000   Received full packet: 010a0200030000000000
Flash voltage set by a strapping pin: 3.3V

Hard resetting via RTS pin...

More Information

the old 4.7.0 release works fine:

esptool.py v4.7.0
Serial port /dev/ttyUSB0
Connecting....
Detecting chip type... Unsupported detection protocol, switching and trying again...
Connecting...
Detecting chip type... ESP32
Chip is ESP32-U4WDH (revision v3.1)
Features: WiFi, BT, Dual Core, 240MHz, Embedded Flash, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz
MAC: a0:a3:b3:dc:ba:18
Uploading stub...
Running stub...
Stub running...
Manufacturer: 20
Device: 4016
Detected flash size: 4MB
Hard resetting via RTS pin..

Other Steps to Reproduce

I tested the hardware I was using:

• Regarding the power supply:
  separate 3.3V power supply instead of the FT232 3.3V output
• Regarding alternative hardware:
  used a different USB converter (FT2232H)

The error message remains the same. Everything works fine with the old release 4.7.0.

I Have Read the Troubleshooting Guide

• I confirm I have read the troubleshooting guide.

[github-actions]

Hi @aanban! Please be aware that (1) the following suggestions are generated by a bot and haven't been fact-checked by Espressif Systems, (2) burning eFuses and enabling security features are irreversible operations and can damage your ESP32 device. We hope that this message will help you until an Espressif Engineer looks at your issue.

---

Based on the information provided in the issue, here are a few key points and troubleshooting steps to resolve this:

1. Test using --no-stub

In esptool v5.x, default behavior and flasher stubs have been restructured [esptool v5 Migration Guide]. The ESP32-U4WDH is an embedded-flash variant [esp32.py target].

Try running the command with the --no-stub flag to bypass uploading the RAM flasher stub and use the ROM bootloader directly:

esptool --port /dev/ttyUSB0 --chip esp32 --no-stub flash-id

If this succeeds with --no-stub, the issue is related to the flasher stub running on this specific chip revision (ESP32-U4WDH v3.1) [Flasher Stub].

2. Check Flash Voltage and Strapping Pins

The output shows:

Flash voltage set by a strapping pin: 3.3V

On standard ESP32 boards, the internal VDD_SDIO regulator defaults to 3.3V unless MTDI (GPIO12) is pulled high at boot [Set Flash Voltage]. However, some embedded-flash ESP32 variants require a specific flash voltage configuration. Ensure MTDI / GPIO12 is not floating or pulled into an unintended state during boot.

3. Lower Baud Rate

Try communicating at a lower baud rate (such as 115200 or 9600) to rule out timing/clock differences between versions:

esptool --port /dev/ttyUSB0 --chip esp32 -b 115200 flash-id

4. Provide Full Trace Log

If running with --no-stub or at a lower baud rate still fails, please run the command with --trace enabled and provide the full non-redacted log:

esptool --port /dev/ttyUSB0 --chip esp32 --trace flash-id

This helps confirm exactly at which packet or command (e.g. SPI_ATTACH or stub execution) the communication is failing [Common Errors].

[aanban]

1.) call with --no-stub argument

OK with --no-stub the flash-id command seems to work:

esptool v5.3.1
Connected to ESP32 on /dev/ttyUSB0:
Chip type:          ESP32-U4WDH (revision v3.1)
Features:           Wi-Fi, BT, Dual Core + LP Core, 240MHz, Embedded Flash, Vref calibration in eFuse, Coding Scheme None
Crystal frequency:  40MHz
MAC:                a0:a3:b3:dc:ba:18
Attaching flash from eFuses' SPI pads configuration (CLK:6, Q:17, D:8, HD:11, CS:16)...
Flash Memory Information:
=========================
Manufacturer: 20
Device: 4016
Detected flash size: 4MB
Flash voltage set by a strapping pin: 3.3V

Hard resetting via RTS pin...

2.) write-flash call with --no-stub argument

However, I think I messed something up when I used the flash-write command.

esptool  --port /dev/ttyUSB0  --chip esp32 --no-stub write-flash 0x00 build/103-shelly/build/firmware.factory.bin

The flashing process is complete, but the firmware is stuck in a boot loop.

esptool v5.3.1
Connected to ESP32 on /dev/ttyUSB0:
Chip type:          ESP32-U4WDH (revision v3.1)
Features:           Wi-Fi, BT, Dual Core + LP Core, 240MHz, Embedded Flash, Vref calibration in eFuse, Coding Scheme None
Crystal frequency:  40MHz
MAC:                a0:a3:b3:dc:ba:18


Attaching flash from eFuses' SPI pads configuration (CLK:6, Q:17, D:8, HD:11, CS:16)...
Configuring flash size...
Note: In case of failure, please set a specific flash size.
Flash will be erased from 0x00000000 to 0x000d9fff...
Wrote 889552 bytes at 0x00000000 in 97.3 seconds (73.2 kbit/s).
Hash of data verified.

Hard resetting via RTS pin...

3.) boot-loop after flash

Boot-Loop after flash, what is the command to set the flash size?:

[20:08:31.068]rst:0x3 (SW_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
[20:08:31.068]configsip: 188777542, SPIWP:0xee
[20:08:31.068]clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
[20:08:31.068]mode:DIO, clock div:2
[20:08:31.068]load:0x3fff0030,len:6248
[20:08:31.068]load:0x40078000,len:15904
[20:08:31.068]load:0x40080400,len:3896
[20:08:31.068]entry 0x40080640
[20:08:31.068]I (161) boot: ESP-IDF v5.5.5 2nd stage bootloader
[20:08:31.068]I (161) boot: Multicore bootloader
[20:08:31.068]I (161) boot: chip revision: v3.1
[20:08:31.068]I (161) boot.esp32: SPI Speed      : 40MHz
[20:08:31.132]I (166) boot.esp32: SPI Mode       : DIO
[20:08:31.132]I (169) boot.esp32: SPI Flash Size : 4MB
[20:08:31.132]I (173) boot: Enabling RNG early entropy source...
[20:08:31.132]I (178) boot: Partition Table:
[20:08:31.132]I (180) boot: ## Label            Usage          Type ST Offset   Length
[20:08:31.132]I (187) boot:  0 otadata          OTA data         01 00 00009000 00002000
[20:08:31.132]I (193) boot:  1 phy_init         RF data          01 01 0000b000 00001000
[20:08:31.132]I (200) boot:  2 app0             OTA app          00 10 00010000 001c0000
[20:08:31.143]I (206) boot:  3 app1             OTA app          00 11 001d0000 001c0000
[20:08:31.143]I (213) boot:  4 nvs              WiFi data        01 02 00390000 00070000
[20:08:31.143]I (220) boot: End of partition table
[20:08:31.143]I (223) esp_image: segment 0: paddr=00010020 vaddr=3f400020 size=22b1ch (142108) map
[20:08:31.212]I (279) esp_image: segment 1: paddr=00032b44 vaddr=3ffb0000 size=03f6ch ( 16236) load
[20:08:31.212]I (286) esp_image: segment 2: paddr=00036ab8 vaddr=40080000 size=09560h ( 38240) load
[20:08:31.212]I (301) esp_image: segment 3: paddr=00040020 vaddr=400d0020 size=8f1b8h (586168) map
[20:08:31.438]I (501) esp_image: segment 4: paddr=000cf1e0 vaddr=40089560 size=0a098h ( 41112) load
[20:08:31.438]I (518) esp_image: segment 5: paddr=000d9280 vaddr=50000000 size=00020h (    32) load
[20:08:31.438]I (528) boot: Loaded app from partition at offset 0x10000
[20:08:31.438]I (528) boot: Disabling RNG early entropy source...
[20:08:32.013][ets Jul 29 2019 12:21:46

[20:08:32.013]rst:0x3 (SW_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
[20:08:32.013]configsip: 188777542, SPIWP:0xee
[20:08:32.013]clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
[20:08:32.013]mode:DIO, clock div:2

[peterdragun]

Hi @aanban I think we are dealing with two separate issues:

1. The stub cannot attach the flash properly - I believe this has been fixed recently in espressif/esp-flasher-stub@e322dc3, but it has not been released yet. You can try using the latest master branch of esptool to confirm if that helps (see our docs on how to install it), or continue using --no-stub until the next release. It would help us if you could confirm that the master branch really fixes your issue even without --no-stub.
2. Boot loop when starting the firmware - does this also appear when using esptool 4.7.0? I don't think this is an issue with esptool itself - the app is restarting itself. There is no panic dump / Guru Meditation, and the reset cause is "SW_RESET," which indicates that the app probably called esp_restart(). This could be as simple as the app detecting that it is connected to a USB-UART bridge and deciding not to continue with code execution. Either way, this seems to be an issue with the firmware, not esptool.

[aanban]

Hi @peterdragun, thanks for the reply.

As I mentioned in my last post, the --no-stub argument works in release v5.3.1

However, I can not confirm that my firmware has a problem, because I have three identical devices (shelly plus 1 gen2) running exactly this firmware.

Here's the history of my tests:

Test 1: Release v5.3.1 (failed)

• flash_id and write_flash terminate with errors (as reported above)

Test 2: Release v4.8.1 (failed)

• flash_id and write_id terminate with errors (It looks like the bug is related to the transition from 4.7 to 4.8.1.)

Test 3: Release 4.7.0 (OK)

• flash_id OK
• write_flash OK
• Firmware runs flawlessly, acts just like the other Shellys.

Test 4: Release v5.3.1

• flash_id with --no-stub OK
• flash_write with --no-stub OK? There was no error message, but an erase operation is performed automatically before flashing
• Firmware gets stuck in a boot loop (failed)

From my perspective, I was able to program three Shellys without any issues using the old 4.7.0 release, and the firmware ran reliably afterward. That's not the case with the current v5.3.1, so the tool itself still has a problem.

Questions:

• Why does the v5.3.1 release with --no-stub first erase the flash memory during the write_flash process? I can imagine that's where the accident happened.

• Is there a way to restore the ESP32 that has been "corrupted" by flashing back to its factory state, so that I can flash it normally again? I'd even be fine using the old 4.7 release. It's kind of a shame that I bricked a Shelly just to report a bug in ESPtool. 😟

[peterdragun]

It is interesting that you mention 4.8.1 does not work as well, as that version should have the same V1/legacy version of the flasher stub as 4.7, which did not have the issue with attaching the flash, as far as I know. Were the errors the same as with 5.3.1 or something different?

Why does the v5.3.1 release with --no-stub first erase the flash memory during the write_flash process? I can imagine that's where the accident happened.

--no-stub does not erase the entire chip. NOR flash must be erased before it is programmed, and with the ROM loader, that erase of the region being written happens first (you will see "Erasing flash..."). The stub just makes that less obvious. If write-flash was given only a bootloader or app file, that region is replaced, and the rest of flash is left as-is, which can leave a device that boots and then resets. Make sure that you have flashed all binaries from the new firmware. A failed stub attach would not have written anything.

Is there a way to restore the ESP32 that has been "corrupted" by flashing back to its factory state, so that I can flash it normally again? I'd even be fine using the old 4.7 release. It's kind of a shame that I bricked a Shelly just to report a bug in ESPtool. 😟

Not sure what you mean here by "corrupted", but without having the original firmware, I don't think you would be able to restore the chip to the "factory state". Please note that it is always recommended to read and save the original contents of the flash in case you want to roll back to old firmware. I believe that you can find the original firmware online, but be careful, as uploading random binary to your device might actually harm it or have other side effects. Another option would be to take firmware from your working device, since you mentioned that you have multiple of them (if they are the same).

Anyway, I don't think you have "bricked" your device; you should still be able to upload a new binary to your ESP32 even if it is in a boot loop.

[aanban]

OK, this is the log from Test2:

esptool.py v4.8.1 
Serial port /dev/ttyUSB0 
Connecting... 
Detecting chip type... Unsupported detection protocol, switching and trying again... 
Connecting... 
Detecting chip type... ESP32 
Chip is ESP32-U4WDH (revision v3.0) 
Features: WiFi, BT, Dual Core, 240MHz, Embedded Flash, VRef calibration in efuse, Coding Scheme None 
Crystal is 40MHz 
MAC: d4:d4:da:f3:9f:04 
Stub is already running. No upload is necessary. 
WARNING: Failed to communicate with the flash chip, read/write operations will fail. Try checking the chip connections or removing any other hardware connected to IOs. 
Manufacturer: ff 
Device: ffff 
Detected flash size: Unknown 
Flash voltage set by a strapping pin to 3.3V 
Hard resetting via RTS pin...

But I'm going to run the test again; to do that, though, I'll have to check out release 4.8.1 again.

Regarding "bricked," yes, you're right—that's not correct; it was the translator's mistake. The ESP32 is still communicating, and it can probably be persuaded to run the firmware again.

I tried flashing the firmware several times with 5.3.1 (--no-stub) and 4.7, but I didn’t find anything in the output that indicated an error. After the reset, it just got stuck in a boot loop.

I’ll try that again and let you know how it goes.

[aanban]

Regarding 4.8.1:
I found the problem. The message "Stub already running..." indicates that I ran Test 2 right after Test 1 without first powering down the ESP32. As a result, it still had the stub firmware from version 5.3.1 loaded, and that caused the attempt to access the flash memory to fail.

Well, I can confirm that 4.8.1 can access the Flash.

[aanban]

Regarding the esptool dev branch:

I checked out the dev branch from Git following the instructions. The tool can now access the flash memory even without the --no-stub option. However, I'm a little confused by the version information. It still shows v5.3.1.

test-esptool-dev ❯ python3 esptool/esptool --port /dev/ttyUSB0 flash-id
esptool v5.3.1
Connected to ESP32 on /dev/ttyUSB0:
Chip type:          ESP32-U4WDH (revision v3.1)
Features:           Wi-Fi, BT, Dual Core + LP Core, 240MHz, Embedded Flash, Vref calibration in eFuse, Coding Scheme None
Crystal frequency:  40MHz
MAC:                a0:a3:b3:dc:ba:18

Stub flasher running.

Flash Memory Information:
=========================
Manufacturer: 20
Device: 4016
Detected flash size: 4MB
Flash voltage set by a strapping pin: 3.3V

Hard resetting via RTS pin...

[aanban]

Regarding the boot loop:

I’ve now reflashed the firmware a few more times. Each time, I made sure to power off the ESP32 before starting the process. Eventually, it worked—the firmware boots up cleanly, and the boot loop no longer occurs.

What should I do next? Should issue #1183 remain open until the new release is published, at which point I’ll verify it again?

[peterdragun]

I checked out the dev branch from Git following the instructions. The tool can now access the flash memory even without the --no-stub option. However, I'm a little confused by the version information. It still shows v5.3.1.

That is correct and expected; we only bump the number with the release. Sorry for the confusion, and thank you for verifying that this fixes the issue.

What should I do next? Should issue #1183 remain open until the new release is published, at which point I’ll verify it again?

No need to verify it again; I just wanted to clarify if this was the main issue here. The release should be done soon, so there won't be many differences compared to the current master branch. Since you confirmed that the issue has been resolved, I will close it.