How to Re-Flashing devices based on iMX7ULP for updating/maintenance once eMMC contains valid image.

[benjamincanton]

Hello, we are trying to understand how we will update and maintain the memories programming of our devices based on i.MX7ULP.

Initial devices flash. We understand that it would be similar to this (if this process will not work please report it):

1. Connect devices to Host throught USB.

2. Host launches script with UUU → UUU stays active waiting for devices listening to.

3. We boot devices and its detect that eMMC are empties → Devices will jump to Serial Download Mode and its wait receiving SDP throught USB.

4. Devices recive UUU script and start the memories programming process.

5. Once programming is completed, we disconnect USB and reboot devices → Programming process is completed and devices should be functional.

We need to figure out how we will easily reflash our based on i.MX7ULP devices .

MAIN QUESTION: How to Re-Flashing devices for updating/maintenance once eMMC contains valid image. Ideally the process should be similar to initial flashing:

• eMMC's of the devices are properly programmed.
• We connect devices through USB to Host.
• Host launch UUU script.
• We boot devices → Devices should jump to Serial Download Mode and will be reprogrammed with the UUU script.

* We don't have an external switch for manually selecting BOOT_MODE[1:0] pins = 00b to jump to Serial Download Mode.

* We cannot access to solded eMMC's to force Serial Download Mode.

how would devices jump to Serial Download Mode in this conditions for being programmed with UUU script from host?

Thanks for your attention.

[benjamincanton]

Hello.

One way we have explore it is to erase mmc memory with linux command and reboot. In this case memory is empty and iMX7ULP jump to SDM.

This is a not usefull solution for masive production and reflashing of the devices. 

We are still looking for a hardware solution which force the device to jump to SDM when we want to reflash, even if mmc is alreadu properly flashed.

Maybe eFuses can be modificated properly so that boot flow tries first to reflash receiving an UUU script on booting, after a while if it doesn't receives any UUU script, normal boot flow go on.

Best regards.

[diegoadrian]

Hello,

I apologize for the delay,

Unfortunately, since the product has not been released yet, we are unable to assist you, I recommend you to go with your DFAE or with your sales representative.

Best regards,

Diego.