ESP32 Forum

Posted: **Tue Sep 28, 2021 8:37 am**

Hello!

I'm struggling to find a solution about totally suppress log output. Here the steps I've done for now:

Bootloader config (from menuconfig): No output

Log output (from menuconfig): No output

It remains only the output log from the first stage bootloader. I already know that with ESP32 I can suppress it by pulling down GPIO15.
But I'm using ESP32-S2 and it doesn't seem to work.

Looking at the Technical Reference I discovered that I can disable the ROM Code Printing to UART by changing the eFuse bits.
In particular I see the point (by using the idf.py show_efuse_table):

Code: Select all

UART_PRINT_CONTROL,               EFUSE_BLK0,  134,    2,     b00:force print. b01:control by GPIO46 - low level print. b10:control by GPIO46 - high level print. b11:force disable print.

And the log says:

Code: Select all

Used bits in efuse table:
EFUSE_BLK0
[0 13] [15 16] [18 18] [20 30] [32 47] [49 51] [56 57] [59 60] [68 70] [80 111] [116 117] [124 130] [132 154]

So I think the two bits are 00 and I can't change this mode of operation.

The question is: am I looking at the right direction? Is there another way to disable the output log of the first stage bootloader?

Thanks in advance,
Filippo

Posted: **Tue Sep 28, 2021 7:53 pm**

Efuse you can set 0 to 1 but you can't set 1 to 0 so it should be fine

Posted: **Tue Sep 28, 2021 9:48 pm**

4. ROM code can be printed over TXD0 (by default) or DAC_1 (IO17), depending on the eFuse bit.

5. When eFuse UART_PRINT_CONTROL value is:
0, print is normal during boot and not controlled by IO46.
1 and IO46 is 0, print is normal during boot; but if IO46 is 1, print is disabled.
2 and IO46 is 0, print is disabled; but if IO46 is 1, print is normal.
3, print is disabled and not controlled by IO46

https://www.espressif.com/sites/default ... eet_en.pdf (page 12)

Posted: **Wed Sep 29, 2021 6:08 am**

WiFive wrote: ↑
Tue Sep 28, 2021 7:53 pm
Efuse you can set 0 to 1 but you can't set 1 to 0 so it should be fine

In fact I think I have to be careful changing eFuse, in my company we have only one ESP32-S2 WROOM at the moment.

chegewara wrote: https://www.espressif.com/sites/default ... eet_en.pdf (page 12)

From this link I understant that it all depends on the eFuse UART_PRINT_CONTROL: in my case I have 00 and it means that print can't be controlled by IO46.
Thank you for your informations, now I'm sure that the only way to suppress ROM's output log depends on eFuse table and GPIO46!

ESP32 Forum

[SOLVED] ESP32-S2 how to suppress output log

[SOLVED] ESP32-S2 how to suppress output log

Re: ESP32-S2 how to suppress output log

Re: ESP32-S2 how to suppress output log

Re: ESP32-S2 how to suppress output log