How to perform OTA operations on ESP32 target with Zephyr 3.5.0 ?

[joelguittet]

Hello community!

I would like to perform OTA on ESP32 with Zephyr.

I have build the hello world example with the following command:

west build -b esp32_devkitc_wroom --sysbuild samples/hello_world

This is generating mcuboot and application. After flashing with west flash and starting espressif monitor with west espressif monitor I have the following result:

Serial port /dev/ttyUSB0
Connecting.....
Detecting chip type... Unsupported detection protocol, switching and trying again...
Connecting....
Detecting chip type... ESP32
--- idf_monitor on /dev/ttyUSB0 115200 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
ets Jun  8 2016 00:22:57
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0000,len:6764
ho 0 tail 12 room 4
load:0x40078000,len:7112
ho 0 tail 12 room 4
load:0x4009c000,len:1024
load:0x4009c400,len:25132
entry 0x4009dd80
[esp32] [INF] MCUboot 2nd stage bootloader
[esp32] [INF] compiled at Dec 12 2023 22:40:27
[esp32] [INF] Chip revision: 1
[esp32] [INF] Chip revision: 1, min. bootloader chip revision: 0
[esp32] [INF] SPI Flash speed: 40MHz, mode: DIO, size: 4MB
[esp32] [INF] Image index: 0, Swap type: test
[esp32] [INF] Loading image 0 - slot 0 from flash, area id: 1
[esp32] [INF] Application start=40084A50h
[esp32] [INF] DRAM segment: paddr=000034D4h, vaddr=3FFB0000h, size=00BB0h (  2992) load
[esp32] [INF] IRAM segment: paddr=00004084h, vaddr=40080000h, size=054FCh ( 21756) load
[esp32] [INF] DROM segment: paddr=00010040h, vaddr=3F400040h, size=03494h ( 13460) map
[esp32] [INF] IROM segment: paddr=00020000h, vaddr=400D0000h, size=15230h ( 86576) map
*** Booting Zephyr OS build zephyr-v3.5.0 ***
Hello World! esp32_devkitc_wroom

Looks not bad until now.

I now wonder how to perform OTA because I don't understand the mcuboot integration. For example after adding mcuboot shell command support I get the following:

uart:~$ mcuboot 
swap type: test
confirmed: 1
primary area (1):
  version: 0.0.0+0
  image size: 152080
  magic: unset
  swap type: none
  copy done: unset
  image ok: unset
failed to read secondary area (2) header: -5

I have added few lines of code (flash_img_init and flash_img_buffered_write) to flash fix data (a 16 bytes array with values from 0 to 15) to the second slot and then verified with the shell it was properly done (flash read at address 0x00110000). This is working.

But at the end I added the following in the code, the function succeeds (it returns 0) but there is not effect when the board reboots:

boot_request_upgrade(BOOT_UPGRADE_TEST); //Checked, it returns 0

While rebooting the device I would expect to have a failure due to invalid data in the second slot.

It seems that the update slot is not used at all. So my question is: anybody succeeded to do OTA on ESP32, with swap or scratch of the partitions ? What is globally the status of OTA support on Espressif devices ?

#29394 indicates mcuboot is supported. Is it only booting ? @sylvioalves ?

Thanks
Joel

[rftafas]

ESP32 REV1 is not supported. May or may not be related to your problem, though.

[rftafas]

Yes, I mean chip revision. In HAL5 we will fix the issue that allows using this device, so I suggest at least getting a Rev3 device.

As for MCUboot, it should work on both ports (Espressif and Zephyr). Other than diving into the docs, you could try hawkbit or the updatehub example and check the internals for better practical examples.

[joelguittet]

Ok, will look for another board on my side definitely to see if I have such a revision.
Is esp32s3 supported maybe (whatever the revision) ? I have one of these somewhere :-)

I know a bit the details, I m the author of https://github.com/joelguittet/mender-mcu-client ;-)

[joelguittet]

@rftafas I was not able to find a rev3 here. Do you know what has been fixed exactly so that I can maybe have a better understanding of the issue ? Why isn't it ported for rev1 for example ?
Do you know how it is possible to purchase a board with a rev3 chip ?

[rftafas]

Do you know what has been fixed exactly so that I can maybe have a better understanding of the issue ?

First, stop and PTAL: #51622 - Besides the security, lots of software workaround to make psram/flash/XIP stable are missing. Also, changes in rom functions.

Why isn't it ported for rev1 for example ?

REV1 is obsolete.

Do you know how it is possible to purchase a board with a rev3 chip ?

I think unless you go to some obscure used devices, everything new should be Rev3

[joelguittet]

I bought the board about 2 years ago only.... :-(

[naNEQ]

I have successfully used ESP32-S3 with MCUBoot, where a new FW image is flashed in the secondary partition over a wireless interface, the partition is marked as requested to update in test mode, exactly as you describe you did, and then at next boot the MCUBoot takes care of the swapping.

I'm not entirely sure I understand your problem, but if I get it right, you attempted to right a dummy image at the second slot? Perhaps I'm wrong, but I think this will not work. If I remember correctly, a proper image contains certain headers that the MCUBoot checks at boot time, and if not satisfied, the swap process is canceled. I recommend you to try with a proper image.

[surendersampath]

@naNEQ That sounds interesting. Do you have an example to try on the esp32-s3? I'd be keen.