esp32c6 flash reboot loop "Failed to fetch app description header" / "Factory app partition is not bootable"

[thecubic]

After flashing a known good Rust program (tested successful with probe-rs on two Xiao C6s), a run --release with espflash causes the device (a C6 DevKit-C) to fail-to-boot and loop infinitely

I'm using espflash 4.0.0-dev as of 628947d

$ cargo run --release
    Finished `release` profile [optimized + debuginfo] target(s) in 0.12s
     Running `espflash flash --monitor target/riscv32imac-unknown-none-elf/release/blinky`
[2025-05-26T18:22:59Z INFO ] Serial port: '/dev/ttyUSB0'
[2025-05-26T18:22:59Z INFO ] Connecting...
[2025-05-26T18:22:59Z INFO ] Using flash stub
Chip type:         esp32c6 (revision v0.1)
Crystal frequency: 40 MHz
Flash size:        8MB
Features:          WiFi 6, BT 5
MAC address:       [REDACTED]
App/part. size:    563,136/8,323,072 bytes, 6.77%
[00:00:01] [========================================]      14/14      0x0                                                                                                                                                                    
[00:00:00] [========================================]       1/1       0x8000                                                                                                                                                                 
[00:00:32] [========================================]     331/331     0x10000                                                                                                                                                                [2025-05-26T18:23:36Z INFO ] Flashing has completed!
Commands:
    CTRL+R    Reset chip
    CTRL+C    Exit

ESP-ROM:esp32c6-20220919
Build:Sep 19 2022
rst:0x1 (POWERON),boot:0xc (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:DIO, clock div:2
load:0x40875720,len:0x16b8
load:0x4086c110,len:0xe90
load:0x4086e610,len:0x3054
entry 0x4086c11a
I (23) boot: ESP-IDF v5.4.1-426-g3ad36321ea 2nd stage bootloader
I (24) boot: compile time Apr 29 2025 15:14:17
I (24) boot: chip revision: v0.1
I (25) boot: efuse block revision: v0.2
I (28) boot.esp32c6: SPI Speed      : 80MHz
I (32) boot.esp32c6: SPI Mode       : DIO
I (36) boot.esp32c6: SPI Flash Size : 8MB
I (40) boot: Enabling RNG early entropy source...
I (44) boot: Partition Table:
I (47) boot: ## Label            Usage          Type ST Offset   Length
I (53) boot:  0 nvs              WiFi data        01 02 00009000 00006000
I (60) boot:  1 phy_init         RF data          01 01 0000f000 00001000
I (66) boot:  2 factory          factory app      00 00 00010000 007f0000
I (73) boot: End of partition table
E (76) esp_image: Failed to fetch app description header!
E (81) boot: Factory app partition is not bootable
E (86) boot: No bootable app partitions in the partition table
ESP-ROM:esp32c6-20220919

[jessebraham]

I believe the issue is that the main branch is using a newer version of the ESP-IDF bootloader which requires the App Image Descriptor to be present, as noted by the logging:

E (76) esp_image: Failed to fetch app description header!

We need to add a warning/error to espflash still to make this more obvious.

Unsure of the details of your application, but if you are using esp-hal you can use the (yet to be released) esp-bootloader-esp-idf crate to add the app descriptor to your application:

esp_bootloader_esp_idf::esp_app_desc!();

This should, I hope, resolve the issue.

[SergioGasquez]

This would be improved once #866 is resolved

[skibon02]

I have the same issue.
However, espflash v3.3.0 works fine

When I add esp-bootloader-esp-idf as suggested by @jessebraham I got linker error:

  = note: [ldproxy] Running ldproxy
          Error: Linker /home/user/projects/esp32-freq-measure/.embuild/espressif/tools/riscv32-esp-elf/esp-13.2.0_20240530/riscv32-esp-elf/bin/riscv32-esp-elf-gcc failed: exit status: 1
          STDERR OUTPUT:
          /home/user/projects/esp32-freq-measure/.embuild/espressif/tools/riscv32-esp-elf/esp-13.2.0_20240530/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/13.2.0/../../../../riscv32-esp-elf/bin/ld: esp-idf/newlib/libnewlib.a(assert.c.obj): in function `__assert_func':
          /home/user/projects/esp32-freq-measure/.embuild/espressif/esp-idf/v5.3.2/components/newlib/assert.c:33: multiple definition of `__assert_func'; /home/user/projects/esp32-freq-measure/target/riscv32imac-esp-espidf/release/deps/libesp_rom_sys-33b0d4242521809f.rlib(esp_rom_sys-33b0d4242521809f.esp_rom_sys.39b0d4fe2ffa2aa2-cgu.0.rcgu.o):esp_rom_sys.39b0d4fe2ffa2aa2-cgu.0:(.text.unlikely.__assert_func+0x0): first defined here
          /home/user/projects/esp32-freq-measure/.embuild/espressif/tools/riscv32-esp-elf/esp-13.2.0_20240530/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/13.2.0/../../../../riscv32-esp-elf/bin/ld: The gap between .flash.appdesc and .flash.rodata must not exist to produce the final bin image.
          collect2: error: ld returned 1 exit status

project is generated by esp-idf-template, and depends on

ESP_IDF_VERSION = "v5.3.2"

[skibon02]

Update

My reboots are a little different:

I (22) boot: ESP-IDF v5.4.1-426-g3ad36321ea 2nd stage bootloader
I (23) boot: compile time Apr 29 2025 15:14:17
I (24) boot: chip revision: v0.1
I (24) boot: efuse block revision: v0.2
I (28) boot.esp32c6: SPI Speed      : 80MHz
I (31) boot.esp32c6: SPI Mode       : DIO
I (35) boot.esp32c6: SPI Flash Size : 16MB
I (39) boot: Enabling RNG early entropy source...
I (43) boot: Partition Table:
I (46) boot: ## Label            Usage          Type ST Offset   Length
I (52) boot:  0 nvs              WiFi data        01 02 00009000 00006000
I (59) boot:  1 phy_init         RF data          01 01 0000f000 00001000
I (65) boot:  2 factory          factory app      00 00 00010000 00fa0000
I (72) boot: End of partition table
E (75) esp_image: Segment 0 load address 0x420c8020, doesn't match data 0x00010020
E (82) boot: Factory app partition is not bootable
E (87) boot: No bootable app partitions in the partition table
ESP-ROM:esp32c6-20220919
Build:Sep 19 2022
rst:0x3 (LP_SW_HPSYS),boot:0x7c (SPI_FAST_FLASH_BOOT)
Saved PC:0x4001974a
SPIWP:0xee
mode:DIO, clock div:2
load:0x40875720,len:0x16b8
load:0x4086c110,len:0xe90
load:0x4086e610,len:0x3054
entry 0x4086c11a
I (22) boot: ESP-IDF v5.4.1-426-g3ad36321ea 2nd stage bootloader
I (23) boot: compile time Apr 29 2025 15:14:17
I (24) boot: chip revision: v0.1
I (24) boot: efuse block revision: v0.2
I (28) boot.esp32c6: SPI Speed      : 80MHz
I (31) boot.esp32c6: SPI Mode       : DIO
I (35) boot.esp32c6: SPI Flash Size : 16MB
I (39) boot: Enabling RNG early entropy source...
I (43) boot: Partition Table:
I (46) boot: ## Label            Usage          Type ST Offset   Length
I (52) boot:  0 nvs              WiFi data        01 02 00009000 00006000
I (59) boot:  1 phy_init         RF data          01 01 0000f000 00001000
I (65) boot:  2 factory          factory app      00 00 00010000 00fa0000
I (72) boot: End of partition table
E (75) esp_image: Segment 0 load address 0x420c8020, doesn't match data 0x00010020
E (82) boot: Factory app partition is not bootable
E (87) boot: No bootable app partitions in the partition table
ESP-ROM:esp32c6-20220919
Build:Sep 19 2022
rst:0x3 (LP_SW_HPSYS),boot:0x7c (SPI_FAST_FLASH_BOOT)
Saved PC:0x4001974a
SPIWP:0xee
mode:DIO, clock div:2
load:0x40875720,len:0x16b8
load:0x4086c110,len:0xe90
load:0x4086e610,len:0x3054
entry 0x4086c11a

The second flavour (when a portion of code is commented out)

I (650) main_task: Calling app_main()
I (650) esp32_display_test: Hello world!

assert failed: mmu_hal_map_region /IDF/components/hal/mmu_hal.c:84 (vaddr % page_size_in_bytes == 0)
Core  0 register dump:
MEPC    : 0x40801998  RA      : 0x40807b86  SP      : 0x40825f10  GP      : 0x40819264  
0x40801998 - panic_abort
    at ??:??
0x40807b86 - $xrv32i2p1_m2p0_a2p1_c2p0_zicsr2p0_zifencei2p0_zmmul1p0
    at ??:??
0x40819264 - s_config
    at ??:??
TP      : 0x408265a0  T0      : 0x37363534  T1      : 0x7271706f  T2      : 0x33323130  
S0/FP   : 0x00000001  S1      : 0x40826094  A0      : 0x40825f68  A1      : 0x4081c63d  
A2      : 0x00000001  A3      : 0x00000029  A4      : 0x00000001  A5      : 0x40822000  
0x40822000 - s_registered_select_num
    at ??:??
A6      : 0x0000001c  A7      : 0x76757473  S2      : 0x00000063  S3      : 0x40825f68  
S4      : 0x40825f68  S5      : 0x4082607c  S6      : 0x00000012  S7      : 0x4081e7f4  
0x4081e7f4 - s_mmu_ctx
    at ??:??
S8      : 0x00000000  S9      : 0x00000001  S10     : 0x408260fc  S11     : 0x00310000  
T3      : 0x6e6d6c6b  T4      : 0x6a696867  T5      : 0x66656463  T6      : 0x62613938  
MSTATUS : 0x00001881  MTVEC   : 0x40800001  MCAUSE  : 0x00000007  MTVAL   : 0x00000000  
0x40800001 - _vector_table
    at ??:??
MHARTID : 0x00000000  

Stack memory:
40825f10: 0x408242e6 0x00000000 0x4081bcf8 0x4080e4f2 0x40826ec0 0x40880000 0x408221e0 0x4081c63c
0x4081bcf8 - __func__.8
    at ??:??
0x4080e4f2 - $xrv32i2p1_m2p0_a2p1_c2p0_zicsr2p0_zifencei2p0_zmmul1p0
    at ??:??
40825f30: 0xa5003438 0x408261b0 0x00000000 0x00000000 0x40000000 0x4081c7b8 0x4081bcf8 0x4081c7c8
0x4081bcf8 - __func__.8
    at ??:??
40825f50: 0x4081c2c8 0x4081c7cc 0x40825f30 0x4081c7d0 0x4081c31c 0x4081c63c 0x65737361 0x66207472
40825f70: 0x656c6961 0x6d203a64 0x685f756d 0x6d5f6c61 0x725f7061 0x6f696765 0x492f206e 0x632f4644
40825f90: 0x6f706d6f 0x746e656e 0x61682f73 0x6d6d2f6c 0x61685f75 0x3a632e6c 0x28203438 0x64646176
40825fb0: 0x20252072 0x65676170 0x7a69735f 0x6e695f65 0x7479625f 0x3d207365 0x2930203d 0x00000000
40825fd0: 0xa5a5a5a5 0xa5a5a5a5 0xa5a5a5a5 0xa5a5a5a5 0x408242e9 0x0000000a 0x408261c4 0x00000000
40825ff0: 0x00000031 0x408265ac 0x40826ec0 0x40808698 0x00000012 0x00000000 0x00000000 0x40022498
0x40808698 - xQueueSemaphoreTake
    at ??:??
40826010: 0x4082944c 0x40880000 0x408221e0 0x40022574 0x40822000 0x00008000 0x00000000 0x0000002c
0x40822000 - s_registered_select_num
    at ??:??
40826030: 0x40822000 0x00000003 0x00000000 0x00008000 0x00000001 0x420e8000 0x00008000 0x4080b1f6
0x40822000 - s_registered_select_num
    at ??:??
0x4080b1f6 - mmu_hal_map_region
    at ??:??
40826050: 0x00000001 0x00008000 0x4082941c 0x00008000 0x00000001 0x00008000 0x420e8000 0x408038ec
0x408038ec - s_do_mapping
    at ??:??
40826070: 0x408242ec 0x0000002c 0x4081e7f4 0x00000000 0x40822000 0x00000003 0x408228c0 0x00008000
0x4081e7f4 - s_mmu_ctx
    at ??:??
0x40822000 - s_registered_select_num
    at ??:??
40826090: 0x4082941c 0x408293ec 0x4082944c 0x4206dda4 0x00000001 0x00001000 0x40826130 0x00000800
0x4206dda4 - esp_mmu_map
    at ??:??
408260b0: 0x00000001 0x00000000 0x00000004 0x00000000 0x00000000 0x00000000 0x00000000 0x40822000
0x40822000 - s_registered_select_num
    at ??:??
408260d0: 0x00000000 0x00001000 0x40826130 0x40826134 0x408293dc 0x408293cc 0x00008000 0x42038fe2
0x42038fe2 - spi_flash_mmap
    at ??:??
408260f0: 0x40808a48 0x4080a7b8 0x40826170 0x00000000 0x40822000 0x00000000 0x00000000 0x40822000
0x40808a48 - vPortClearInterruptMaskFromISR
    at ??:??
0x4080a7b8 - xTaskGenericNotify
    at ??:??
0x40822000 - s_registered_select_num
    at ??:??
0x40822000 - s_registered_select_num
    at ??:??
40826110: 0x420d0f5c 0x00000002 0x00000001 0x4203841c 0x40822000 0x40822000 0x00000000 0x20001090
0x4203841c - ensure_partitions_loaded.part.0
    at ??:??
0x40822000 - s_registered_select_num
    at ??:??
0x40822000 - s_registered_select_num
    at ??:??
40826130: 0x4081d010 0x408261e0 0x00000000 0x00000000 0x00000000 0x408261f4 0x408261f0 0x408272f4
0x4081d010 - pxReadyTasksLists
    at ??:??
40826150: 0x00000000 0x00000000 0x67452301 0xefcdab89 0x98badcfe 0x10325476 0x00000000 0x00000000
40826170: 0x4201193e 0x00000000 0x00000000 0x00000054 0x40822000 0x00000003 0x408228c0 0x40801d70
0x4201193e - std::sys::pal::unix::thread::Thread::new
    at ??:??
0x40822000 - s_registered_select_num
    at ??:??
0x40801d70 - heap_caps_aligned_alloc_base
    at ??:??
40826190: 0x00000000 0x00000000 0x408292f0 0x4080810e 0x40829298 0x00000000 0x00000000 0x00000000
0x4080810e - xQueueGenericSend
    at ??:??
408261b0: 0x00000804 0x00000054 0x40822014 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x40822014 - nvs::NVSPartitionManager::instance
    at ??:??
408261d0: 0x00000000 0x00000000 0x00000000 0x40822000 0x420d0f5c 0x00000002 0x00000001 0x420386e2
0x40822000 - s_registered_select_num
    at ??:??
0x420386e2 - esp_partition_find
    at ??:??
408261f0: 0x40822000 0x00000003 0x408228c0 0x00000000 0x4082623c 0x40829348 0x420d0f5c 0x4203873a
0x40822000 - s_registered_select_num
    at ??:??
0x4203873a - esp_partition_find_first
    at ??:??
40826210: 0x00000000 0x40829348 0x420d0f5c 0x4204650c 0x40818b80 0x40829348 0x420d0f5c 0x42044c0c
0x4204650c - nvs::partition_lookup::lookup_nvs_partition(char const*, nvs::NVSPartition**)
    at ??:??
0x40818b80 - $d
    at ??:??
0x42044c0c - nvs::NVSPartitionManager::init_partition(char const*)
    at ??:??
40826230: 0x40818b80 0x420d0f5c 0x40822000 0x00000000 0x40818b80 0x420d0f5c 0x00000000 0x42043050
0x40818b80 - $d
    at ??:??
0x40822000 - s_registered_select_num
    at ??:??
0x40818b80 - $d
    at ??:??
0x42043050 - nvs_flash_init_partition
    at ??:??
40826250: 0x40822000 0x00000001 0x40818b80 0x420408b6 0x00000000 0x00000001 0x00000001 0x420075e0
0x40822000 - s_registered_select_num
    at ??:??
0x40818b80 - $d
    at ??:??
0x420408b6 - pthread_mutex_lock
    at ??:??
0x420075e0 - esp_idf_svc::nvs::EspNvsPartition<esp_idf_svc::nvs::NvsDefault>::take_with
    at ??:??
40826270: 0x00000000 0x00000000 0x00000000 0x00000000 0x00001800 0x00000008 0x00000000 0x40801a48
0x40801a48 - heap_caps_malloc
    at ??:??
40826290: 0x00000001 0x40818b60 0x00000000 0x4200613c 0x00000000 0x00000001 0x40828254 0x42002136
0x40818b60 - $d
    at ??:??
0x4200613c - esp_idf_svc::eventloop::EspEventLoop<esp_idf_svc::eventloop::System>::take
    at ??:??
0x42002136 - esp32_display_test::main
    at ??:??
408262b0: 0xa5a5a5a5 0xa5a5a5a5 0xa5a5a5a5 0x40828254 0xa5a5a5a5 0xa5a5a5a5 0xa5a5a5a5 0xa5a5a5a5
408262d0: 0xa5a5a5a5 0xa5a5a5a5 0xa5a5a5a5 0xa5a5a5a5 0x0000028a 0xa5a5a5a5 0xa5a5a5a5 0xa5a5a5a5
408262f0: 0x420cefc8 0xa5a5a5a5 0xa5a5a5a5 0xa5a5a5a5 0x00000000 0xa5a5a5a5 0x408271f0 0x408272bc



ELF file SHA256: 000000000

Rebooting...
ESP-ROM:esp32c6-20220919
Build:Sep 19 2022
rst:0xc (SW_CPU),boot:0x7c (SPI_FAST_FLASH_BOOT)
Saved PC:0x4001975a
SPIWP:0xee
mode:DIO, clock div:2
load:0x40875720,len:0x16b8
load:0x4086c110,len:0xe90
load:0x4086e610,len:0x3054
entry 0x4086c11a
I (22) boot: ESP-IDF v5.4.1-426-g3ad36321ea 2nd stage bootloader

[skibon02]

Can be reproduced with default esp-idf-template generated project when built without optimizations, looks like behavior depends on the binary size

[skibon02]

Also, there is a difference in bootloader output on the same chip with the same program:

espflash v3.3.0

I (23) boot: ESP-IDF v5.1-beta1-378-gea5e0ff298-dirt 2nd stage bootloader
I (24) boot: compile time Jun  7 2023 08:02:08
I (25) boot: chip revision: v0.1
I (29) boot.esp32c6: SPI Speed      : 40MHz
I (33) boot.esp32c6: SPI Mode       : DIO
I (38) boot.esp32c6: SPI Flash Size : 4MB

espflash v4.0.0

I (22) boot: ESP-IDF v5.4.1-426-g3ad36321ea 2nd stage bootloader
I (23) boot: compile time Apr 29 2025 15:14:17
I (24) boot: chip revision: v0.1
I (24) boot: efuse block revision: v0.2
I (28) boot.esp32c6: SPI Speed      : 80MHz
I (31) boot.esp32c6: SPI Mode       : DIO
I (35) boot.esp32c6: SPI Flash Size : 16MB

[SergioGasquez]

esp-bootloader-esp-idf is used for no_std apps (esp-hal based), since you are building an std app, you should use the std version of the macro, I think its esp_idf_sys::esp_app_desc.

Can you try running esptool flash_id on your devkit? The fact that espflash@3.3 and 4.0 give a different spi flash size is weird

[skibon02]

Yeah, probably I should've created a new issue for this, since in my case I don't have Failed to fetch app description header! message

1. flash_id output

$ esptool.py --chip esp32c6 --port /dev/ttyACM0 flash_id
esptool.py v4.8.1
Serial port /dev/ttyACM0
Connecting....
Chip is ESP32-C6 (QFN40) (revision v0.1)
Features: WiFi 6, BT 5, IEEE802.15.4
Crystal is 40MHz
MAC: f0:f5:bd:ff:fe:10:49:48
BASE MAC: f0:f5:bd:10:49:48
MAC_EXT: ff:fe
Uploading stub...
Running stub...
Stub running...
Manufacturer: 85
Device: 2018
Detected flash size: 16MB
Hard resetting via RTS pin...

2. Running espflash@4.0.0 for the fresh esp-idf-template project

$ espflash flash --monitor target/riscv32imac-esp-espidf/release/remote-tester 
[2025-07-07T08:27:27Z INFO ] Serial port: '/dev/ttyACM0'
[2025-07-07T08:27:27Z INFO ] Connecting...
[2025-07-07T08:27:27Z INFO ] Using flash stub
Chip type:         esp32c6 (revision v0.1)
Crystal frequency: 40 MHz
Flash size:        16MB
Features:          WiFi 6, BT 5
MAC address:       f0:f5:bd:10:49:48
App/part. size:    406,576/16,384,000 bytes, 2.48%
[00:00:01] [========================================]      14/14      0x0      Verifying... OK!            
[00:00:00] [========================================]       1/1       0x8000   Verifying... OK!            
[00:00:24] [========================================]     233/233     0x10000  Verifying... OK!                                                                                                                                     
[2025-07-07T08:27:54Z INFO ] Flashing has completed!                                                                                                                                                                                
Commands:
    CTRL+R    Reset chip
    CTRL+C    Exit

ESP-ROM:esp32c6-20220919
Build:Sep 19 2022
rst:0x1 (POWERON),boot:0xc (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:DIO, clock div:2
load:0x40875720,len:0x16b8
load:0x4086c110,len:0xe90
load:0x4086e610,len:0x3054
entry 0x4086c11a
I (23) boot: ESP-IDF v5.4.1-426-g3ad36321ea 2nd stage bootloader
I (24) boot: compile time Apr 29 2025 15:14:17
I (24) boot: chip revision: v0.1
I (25) boot: efuse block revision: v0.3
I (28) boot.esp32c6: SPI Speed      : 80MHz
I (32) boot.esp32c6: SPI Mode       : DIO
I (36) boot.esp32c6: SPI Flash Size : 16MB
I (40) boot: Enabling RNG early entropy source...
I (44) boot: Partition Table:
I (47) boot: ## Label            Usage          Type ST Offset   Length
I (53) boot:  0 nvs              WiFi data        01 02 00009000 00006000
I (60) boot:  1 phy_init         RF data          01 01 0000f000 00001000
I (66) boot:  2 factory          factory app      00 00 00010000 00fa0000
I (73) boot: End of partition table
E (76) esp_image: Segment 0 load address 0x42048020, doesn't match data 0x00010020
E (83) boot: Factory app partition is not bootable
E (88) boot: No bootable app partitions in the partition table
ESP-ROM:esp32c6-20220919
Build:Sep 19 2022
rst:0x3 (LP_SW_HPSYS),boot:0xc (SPI_FAST_FLASH_BOOT)
Saved PC:0x4001974a
SPIWP:0xee
mode:DIO, clock div:2
load:0x40875720,len:0x16b8
load:0x4086c110,len:0xe90
load:0x4086e610,len:0x3054
entry 0x4086c11a
I (24) boot: ESP-IDF v5.4.1-426-g3ad36321ea 2nd stage bootloader
I (24) boot: compile time Apr 29 2025 15:14:17
I (25) boot: chip revision: v0.1
I (25) boot: efuse block revision: v0.3
I (29) boot.esp32c6: SPI Speed      : 80MHz
I (33) boot.esp32c6: SPI Mode       : DIO
I (37) boot.esp32c6: SPI Flash Size : 16MB
I (40) boot: Enabling RNG early entropy source...
I (45) boot: Partition Table:
I (48) boot: ## Label            Usage          Type ST Offset   Length
I (54) boot:  0 nvs              WiFi data        01 02 00009000 00006000
I (60) boot:  1 phy_init         RF data          01 01 0000f000 00001000
I (67) boot:  2 factory          factory app      00 00 00010000 00fa0000
I (74) boot: End of partition table
E (77) esp_image: Segment 0 load address 0x42048020, doesn't match data 0x00010020
E (84) boot: Factory app partition is not bootable
E (88) boot: No bootable app partitions in the partition table
ESP-ROM:esp32c6-20220919
Build:Sep 19 2022
rst:0x3 (LP_SW_HPSYS),boot:0xc (SPI_FAST_FLASH_BOOT)
Saved PC:0x4001974a
SPIWP:0xee
mode:DIO, clock div:2
load:0x40875720,len:0x16b8
load:0x4086c110,len:0xe90
load:0x4086e610,len:0x3054
entry 0x4086c11a
I (24) boot: ESP-IDF v5.4.1-426-g3ad36321ea 2nd stage bootloader

... endless reboots ...

[MabezDev]

Can you try setting the flash speed manually back to 40mhz? I think -f 40mhz should do it.

[SergioGasquez]

Just tried generating a fresh esp-idf-template project(with default values) and flashing an ESP32-C6-DevKitC-1 with no issues:

Full log

> cargo r -r
    Finished `release` profile [optimized] target(s) in 0.08s
     Running `espflash flash --monitor target/riscv32imac-esp-espidf/release/app-des`
[2025-07-07T10:22:28Z INFO ] Serial port: '/dev/cu.usbserial-1120'
[2025-07-07T10:22:28Z INFO ] Connecting...
[2025-07-07T10:22:28Z INFO ] Using flash stub
[2025-07-07T10:22:29Z WARN ] Setting baud rate higher than 115,200 can cause issues
Chip type:         esp32c6 (revision v0.0)
Crystal frequency: 40 MHz
Flash size:        8MB
Features:          WiFi 6, BT 5
MAC address:       60:55:f9:f7:1b:6c
App/part. size:    382,384/8,323,072 bytes, 4.59%
[00:00:00] [========================================]      14/14      0x0      Verifying... OK!                            [00:00:00] [========================================]       1/1       0x8000   Verifying... OK!                            [00:00:06] [========================================]     199/199     0x10000  Verifying... OK!                            [2025-07-07T10:22:36Z INFO ] Flashing has completed!
Commands:
    CTRL+R    Reset chip
    CTRL+C    Exit

ESP-ROM:esp32c6-20220919
Build:Sep 19 2022
rst:0x1 (POWERON),boot:0xc (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:DIO, clock div:2
load:0x40875720,len:0x16b8
load:0x4086c110,len:0xe90
load:0x4086e610,len:0x3054
entry 0x4086c11a
I (23) boot: ESP-IDF v5.4.1-426-g3ad36321ea 2nd stage bootloader
I (24) boot: compile time Apr 29 2025 15:14:17
I (24) boot: chip revision: v0.0
I (25) boot: efuse block revision: v0.0
I (28) boot.esp32c6: SPI Speed      : 80MHz
I (32) boot.esp32c6: SPI Mode       : DIO
I (36) boot.esp32c6: SPI Flash Size : 8MB
I (40) boot: Enabling RNG early entropy source...
I (44) boot: Partition Table:
I (47) boot: ## Label            Usage          Type ST Offset   Length
I (53) boot:  0 nvs              WiFi data        01 02 00009000 00006000
I (60) boot:  1 phy_init         RF data          01 01 0000f000 00001000
I (66) boot:  2 factory          factory app      00 00 00010000 007f0000
I (73) boot: End of partition table
I (76) esp_image: segment 0: paddr=00010020 vaddr=42040020 size=11db0h ( 73136) map
I (97) esp_image: segment 1: paddr=00021dd8 vaddr=40800000 size=0922ch ( 37420) load
I (106) esp_image: segment 2: paddr=0002b00c vaddr=40809230 size=01bdch (  7132) load
I (108) esp_image: segment 3: paddr=0002cbf0 vaddr=00000000 size=03428h ( 13352) 
I (112) esp_image: segment 4: paddr=00030020 vaddr=42000020 size=3d568h (251240) map
I (165) boot: Loaded app from partition at offset 0x10000
I (166) boot: Disabling RNG early entropy source...
I (175) cpu_start: Unicore app
W (185) clk: esp_perip_clk_init() has not been implemented yet
I (192) cpu_start: Pro cpu start user code
I (192) cpu_start: cpu freq: 160000000 Hz
I (192) cpu_start: Application information:
I (195) cpu_start: Project name:     libespidf
I (200) cpu_start: App version:      1
I (204) cpu_start: Compile time:     Jul  7 2025 12:13:58
I (210) cpu_start: ELF file SHA256:  000000000...
I (216) cpu_start: ESP-IDF:          v5.2.3
I (221) cpu_start: Min chip rev:     v0.0
I (225) cpu_start: Max chip rev:     v0.99 
I (230) cpu_start: Chip rev:         v0.0
I (235) heap_init: Initializing. RAM available for dynamic allocation:
I (242) heap_init: At 4080BE20 len 000707F0 (449 KiB): RAM
I (248) heap_init: At 4087C610 len 00002F54 (11 KiB): RAM
I (254) heap_init: At 50000000 len 00003FE8 (15 KiB): RTCRAM
I (261) spi_flash: detected chip: generic
I (265) spi_flash: flash io: dio
W (269) eFuse: calibration efuse version does not match, set default version to 0
W (285) eFuse: calibration efuse version does not match, set default version to 0
W (286) eFuse: calibration efuse version does not match, set default version to 0
W (294) eFuse: calibration efuse version does not match, set default version to 0
W (302) eFuse: calibration efuse version does not match, set default version to 0
W (310) eFuse: calibration efuse version does not match, set default version to 0
W (318) eFuse: calibration efuse version does not match, set default version to 0
W (327) eFuse: calibration efuse version does not match, set default version to 0
W (335) eFuse: calibration efuse version does not match, set default version to 0
W (350) eFuse: calibration efuse version does not match, set default version to 0
W (351) eFuse: calibration efuse version does not match, set default version to 0
W (359) eFuse: calibration efuse version does not match, set default version to 0
W (367) eFuse: calibration efuse version does not match, set default version to 0
W (376) eFuse: calibration efuse version does not match, set default version to 0
W (384) eFuse: calibration efuse version does not match, set default version to 0
W (392) eFuse: calibration efuse version does not match, set default version to 0
W (400) eFuse: calibration efuse version does not match, set default version to 0
W (415) eFuse: calibration efuse version does not match, set default version to 0
W (416) eFuse: calibration efuse version does not match, set default version to 0
W (425) eFuse: calibration efuse version does not match, set default version to 0
W (433) eFuse: calibration efuse version does not match, set default version to 0
W (441) eFuse: calibration efuse version does not match, set default version to 0
W (449) eFuse: calibration efuse version does not match, set default version to 0
W (457) eFuse: calibration efuse version does not match, set default version to 0
W (465) eFuse: calibration efuse version does not match, set default version to 0
W (481) eFuse: calibration efuse version does not match, set default version to 0
W (482) eFuse: calibration efuse version does not match, set default version to 0
W (490) eFuse: calibration efuse version does not match, set default version to 0
W (498) eFuse: calibration efuse version does not match, set default version to 0
W (506) eFuse: calibration efuse version does not match, set default version to 0
W (514) eFuse: calibration efuse version does not match, set default version to 0
W (522) eFuse: calibration efuse version does not match, set default version to 0
W (531) pcnt(legacy): legacy driver is deprecated, please migrate to `driver/pulse_cnt.h`
W (539) i2c: This driver is an old driver, please migrate your application code to adapt `driver/i2c_master.h`
W (550) timer_group: legacy driver is deprecated, please migrate to `driver/gptimer.h`
I (559) sleep: Configure to isolate all GPIO pins in sleep state
I (565) sleep: Enable automatic switching of GPIO sleep configuration
I (572) coexist: coex firmware version: 27d8387
I (578) coexist: coexist rom version 5b8dcfa
I (583) main_task: Started on CPU0
I (583) main_task: Calling app_main()
I (583) app_des: Hello, world!
I (593) main_task: Returned from app_main()

[skibon02]

It just skipped reflashing step:

$ espflash flash -f 40mhz --monitor target/riscv32imac-esp-espidf/release/remote-tester
[2025-07-07T10:26:36Z INFO ] Serial port: '/dev/ttyACM0'
[2025-07-07T10:26:36Z INFO ] Connecting...
[2025-07-07T10:26:36Z INFO ] Using flash stub
Chip type:         esp32c6 (revision v0.1)
Crystal frequency: 40 MHz
Flash size:        16MB
Features:          WiFi 6, BT 5
MAC address:       f0:f5:bd:10:49:48
App/part. size:    406,576/16,384,000 bytes, 2.48%
[00:00:00] [========================================]      14/14      0x0      Skipped! (checksum matches)                                                                                                                          
[00:00:00] [========================================]       1/1       0x8000   Skipped! (checksum matches)                                                                                                                          
[00:00:00] [========================================]     233/233     0x10000  Skipped! (checksum matches)

... endless reboots

Trying different frequency

$ espflash flash -f 80mhz --monitor target/riscv32imac-esp-espidf/release/remote-tester
[2025-07-07T10:27:27Z INFO ] Serial port: '/dev/ttyACM0'
[2025-07-07T10:27:27Z INFO ] Connecting...
[2025-07-07T10:27:27Z INFO ] Using flash stub
Chip type:         esp32c6 (revision v0.1)
Crystal frequency: 40 MHz
Flash size:        16MB
Features:          WiFi 6, BT 5
MAC address:       f0:f5:bd:10:49:48
App/part. size:    406,576/16,384,000 bytes, 2.48%
[00:00:01] [========================================]      14/14      0x0      Verifying... OK!                                                                                                                                     
[00:00:00] [========================================]       1/1       0x8000   Skipped! (checksum matches)                                                                                                                          
[00:00:24] [========================================]     233/233     0x10000  Verifying... OK!                                                                                                                                     
[2025-07-07T10:27:53Z INFO ] Flashing has completed!                                                                                                                                                                                
Commands:
    CTRL+R    Reset chip
    CTRL+C    Exit

ESP-ROM:esp32c6-20220919
Build:Sep 19 2022
rst:0x1 (POWERON),boot:0xc (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:DIO, clock div:1
load:0x40875720,len:0x16b8
load:0x4086c110,len:0xe90
load:0x4086e610,len:0x3054
entry 0x4086c11a
I (23) boot: ESP-IDF v5.4.1-426-g3ad36321ea 2nd stage bootloader
I (24) boot: compile time Apr 29 2025 15:14:17
I (24) boot: chip revision: v0.1
I (25) boot: efuse block revision: v0.3
I (28) boot.esp32c6: SPI Speed      : 80MHz
I (32) boot.esp32c6: SPI Mode       : DIO
I (36) boot.esp32c6: SPI Flash Size : 16MB
I (40) boot: Enabling RNG early entropy source...
I (44) boot: Partition Table:
I (47) boot: ## Label            Usage          Type ST Offset   Length
I (53) boot:  0 nvs              WiFi data        01 02 00009000 00006000
I (60) boot:  1 phy_init         RF data          01 01 0000f000 00001000
I (66) boot:  2 factory          factory app      00 00 00010000 00fa0000
I (73) boot: End of partition table
E (76) esp_image: Segment 0 load address 0x42048020, doesn't match data 0x00010020
E (83) boot: Factory app partition is not bootable
E (88) boot: No bootable app partitions in the partition table

[SergioGasquez]

Can you try updating the espflash command to espflash flash --monitor --no-skip --flash-size 8mb?