Back to factory APP (OTA)

[urbanze]

Once the OTA's updates are made in the OTA sections, the Factory APP is intact, so what is the procedure to return to the first code, stored in the Factory?

[chegewara]

https://esp32.com/viewtopic.php?f=13&t= ... 908#p16328

[p-rimes]

That thread is very interesting indeed.

A couple things were not finalized in that thread:

• Are the patches to the bootloader still needed at this point? Is there any way for a typical "factory reset" other than duplicating the bootloader sources into each app, and making a similar patch (and presumably keeping everything in lockstep with esp-idf forever afterwards)?
• Is there a way to transfer control flow to a different partition (i.e. the just-programmed one, or back to factory), WITHOUT a reboot?
• Does the esp-idf bootloader do a fallback boot to factory, in case of a corrupt image?

[chegewara]

Use
http://esp-idf.readthedocs.io/en/latest ... btype_tPKc
with
http://esp-idf.readthedocs.io/en/latest ... artition_t

or read this:
http://esp-idf.readthedocs.io/en/latest ... -partition

[urbanze]

That thread is very interesting indeed.

A couple things were not finalized in that thread:

• Are the patches to the bootloader still needed at this point? Is there any way for a typical "factory reset" other than duplicating the bootloader sources into each app, and making a similar patch (and presumably keeping everything in lockstep with esp-idf forever afterwards)?
• Is there a way to transfer control flow to a different partition (i.e. the just-programmed one, or back to factory), WITHOUT a reboot?
• Does the esp-idf bootloader do a fallback boot to factory, in case of a corrupt image?

I made some tests with image (binary) sending and all editions (simple) that I tested, returned error when finalizing the update, that is, we are already prevented from several inconveniences like loss of bytes when transferring the data through WiFi/etc.
I tried to lose bytes in the transfer and also to exchange bytes for others, to simulate a corrupted byte such as 0x45 by 0x46. Both tests I did several times were not loaded and the current boot partition kept running.

The function that always returns this error is "esp_ota_end (update_handle)" "(ESP_ERR_OTA_VALIDATE_FAILED)"

I know they are simple tests but they are the easiest to do in practice mainly with Wireless communications, I believe. This is great for us!
However, if the binary is correct (but not the code, for example an infinite loop), we can try to make a RESET REASON check and thus booting the APP factory, it's simple and maybe it works very well!

[urbanze]

Use
http://esp-idf.readthedocs.io/en/latest ... btype_tPKc
with
http://esp-idf.readthedocs.io/en/latest ... artition_t

or read this:
http://esp-idf.readthedocs.io/en/latest ... -partition

Oh, I had not seen this partitions reference, there is a function in that reference that can return the pointer to the factory app and so loads it, thanks!

[Edzelf]

You could execute this snippet to restore the factory version:

Code: Select all

//***********************************************************************************************
//                                B A C K T O F A C T O R Y                                     *
//***********************************************************************************************
// Return to factory version.                                                                   *
// This will set the otadata to boot from the factory image, ignoring previous OTA updates.     *
//***********************************************************************************************
void backtofactory()
{
    esp_partition_iterator_t  pi ;                                  // Iterator for find
    const esp_partition_t*    factory ;                             // Factory partition
    esp_err_t                 err ;

    pi = esp_partition_find ( ESP_PARTITION_TYPE_APP,               // Get partition iterator for
                              ESP_PARTITION_SUBTYPE_APP_FACTORY,    // factory partition
                              "factory" ) ;
    if ( pi == NULL )                                               // Check result
    {
        ESP_LOGE ( tag, "Failed to find factory partition" ) ;
    }
    else
    {
        factory = esp_partition_get ( pi ) ;                        // Get partition struct
        esp_partition_iterator_release ( pi ) ;                     // Release the iterator
        err = esp_ota_set_boot_partition ( factory ) ;              // Set partition for boot
        if ( err != ESP_OK )                                        // Check error
	{
            ESP_LOGE ( tag, "Failed to set boot partition" ) ;
	}
	else
	{
            esp_restart() ;                                         // Restart ESP
        }
    }
}

[chegewara]

I thought about changing bootloader to have option to restart esp32 from factory partition.
Pros:
- i dont need to add code snippet to each application and i can use for example vanilla esp-idf examples to ota update (my current project)
Cons:
- gpio used to revert to factory partition is hardcoded in bootloader and cant be changed in different applications.

[solam4]

Use
http://esp-idf.readthedocs.io/en/latest ... btype_tPKc
with
http://esp-idf.readthedocs.io/en/latest ... artition_t

or read this:
http://esp-idf.readthedocs.io/en/latest ... -partition

Are bootloader patch requirements still required? Is there a way to perform a "factory reset" without duplicated bootloader sources for each app?
Can control flows be transferred between partitions without requiring a reboot?
Does the esp-idd bootloader support fallback boot to factory in case of image corruption?