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ROM Serial Bootlader
Posted: Thu May 09, 2019 8:58 am
by fgerenli
Hi to all.
There is a ROM serial bootloader residing in the ROM of the SoC as i know. It is triggered during the power on by the configuraiton of bootstrapping pins.
I wonder if it is possible to trigger ROM serial bootlader from flash application. I mean of course for the first time i will flash my appplication by using ROM serial bootlader and bootstrapping pins. But for the next time, i will call ROM serial bootlader from my application if i receive a special BLE message for example, without a need of bootstrapping pin configuration. Is it possible?
Regards.
Re: ROM Serial Bootlader
Posted: Thu May 09, 2019 11:51 am
by ESP_igrr
No, this is not possible. ROM download mode can only be triggered by strapping pins configuration. It can also not be entered from IDF using a function call, as the ROM bootloader uses static memory range which is used in IDF for the heap.
You can however use the esp_ota_* APIs to perform an update. The source of the update can be anything: downloading a binary file over HTTPS, reading it from the UART via Ymodem protocol, loading it from an SD card, etc.
Re: ROM Serial Bootlader
Posted: Thu May 09, 2019 2:03 pm
by fgerenli
Thank you Ivan.
It is a good idea to use OTA API with an "alternative data input port".
Below is a part of the esp_https_ota source under "esp-idf/components". Examining the the whole source, it seems it is possible to make it working.
Code: Select all
while (1) {
int data_read = esp_http_client_read(client, upgrade_data_buf, alloc_size);
if (data_read == 0) {
ESP_LOGI(TAG, "Connection closed, all data received");
break;
}
if (data_read < 0) {
ESP_LOGE(TAG, "Error: SSL data read error");
break;
}
if (data_read > 0) {
ota_write_err = esp_ota_write(update_handle, (const void *) upgrade_data_buf, data_read);
if (ota_write_err != ESP_OK) {
break;
}
binary_file_len += data_read;
ESP_LOGD(TAG, "Written image length %d", binary_file_len);
}
}
We will give a try with a new function to read the new binary from UART instead of HTTP server. Of course editing the rest.
Regards.
Re: ROM Serial Bootlader
Posted: Mon Jun 10, 2019 9:22 am
by tangqingcai
hello fgerenli ;
you say you will "give a try with a new function to read the new binary from UART " ?
is there achieved?
i have an idea about esp32 connect to MCU(like STM32) via UART;
then i want to upgrade esp32 firmware by STM32 via UART in bootloader step;
perhaps it is same to your function;