Hi, I read the related topic here and can’t get the MB1 -> MB2 -> CBOOT “combined uart” to be disabled.
We tried this in several of the .cfg files without success (the system locks up and appears to not finish booting… we’re using SSH to login):
enable_combined_uart = 0;
Instead, we manually disabled the UART (e.g., intercept the printing function) during CBOOT and during standard Jetpack 4.3 kernel bootup (by removing the “console=ttyTCU0” from the kernel commandline passed from CBOOT).
We also need to disable the UART during MB1, MB2, Trusty, SPE, CBOOT and any other IP Blocks which might use the UART during startup. Our goal is to boot faster. We are booting to eMMC without a display.
An example of the MB1 text output to the UART is shown below:
you may update below configuration file to disable bootloader messages;
please refer to Topic 145106 for more details.
Ok, I tried the suggestions from the other Topic 122047 and the results are not good:
debug.enable_log = 0;
spe_uart_instance = 0xFF;
After doing this change, the flashing system stopped halfway through the flash mechanism. After reverting the files back to “spe_uart_instance = 2” I was able to revert the changes and reflash to a working system (which still outputs the stuff above).
The items above look like they might originate from the SPE. Some of the SPE sources are available, but it doesn’t look like it is the “spe_combined_uart” so I’m not sure how to disable the UART text yet. We also run Trusty which could be emitting the messages maybe.
I looked through the SPE source code and the Trusty source code and neither one have most of the message text above. So I’m guessing it’s MB1 or MB2 text which is not properly silenced using “Verbosity=0”
it correct by setting Verbosity=0 cannot disable MB1 and MB2 messages, you should further to modify the header file to update the log levels;
please access CBoot sources via download center, you might refer to post #18 in Topic 122047 to have changes to disable uart-message for MB2/cboot.
Hi Jerry, I downloaded and built the cboot sources and applied the changes in post #18 of Topic 122047. The result is the text above. Yes, the amount of text is greatly reduced, but it’s not near zero.
is there something you see which makes you think the text comes from cboot instead of mb2 or spe? For instance, I can’t find the word “speedo” in any of the cboot source code.
If I grep through the Nvidia Jetpack source and binaries for “speedo” I get this: