topic Re: IMX8MM u-boot and kernel silent in i.MX Processors

IMX8MM u-boot and kernel silent

baptiste — Thu, 13 Apr 2023 07:39:33 GMT

Hi,

I want to reduce my design boot time.
I follow the AN13709 guide, but no way.

I use yocto with an EVK Board (Imx8Nano_EVK board, but the processor is an IMX8Mini).

Could you help me to ?

1 - Silent u-boot
Autoboot delay = -2 OK (in imx8mm_evk.k)
But i don't want u-boot write to serial, how can i achieve this permanently with yocto ?

2 - Silent Kernel

How to set bootargs with quiet args (always with Yocto) and permanently (for mass production).

Best regards,
Baptiste

Re: IMX8MM u-boot and kernel silent

Zhiming_Liu — Tue, 18 Apr 2023 02:27:23 GMT

For your question one and two, you can import patch in yocto, like disable-uboot-serial.patch and queit-bootargs.patch, modify the u-boot-imx_2022.04.b refering this :https://stackoverflow.com/questions/45584131/how-patching-works-in-yocto

For disabling the serial in uboot, you can try below code:

Add the following defines to the board's config header(located in include/configs/imx8mm_board.h

  #define CONFIG_DISABLE_CONSOLE
  #define CONFIG_SILENT_CONSOLE
  #define CONFIG_SYS_DEVICE_NULLDEV

Add below code in board_early_init_f(board/freescale/imx8mm_evk/imx8mm_evk.c), gd->flags |= (GD_FLG_SILENT | GD_FLG_DISABLE_CONSOLE

Re: IMX8MM u-boot and kernel silent

baptiste — Thu, 20 Apr 2023 11:18:23 GMT

Hi QMiller,

Thanks for your reply.

I don't find but include/configs/imx8mm_evk.h
I have put this :

#define CONFIG_BOOTDELAY -2

#define CONFIG_DISABLE_CONSOLE #define CONFIG_SILENT_CONSOLE #define CONFIG_SYS_DEVICE_NULLDEV

I have put code in board_early_init_f(board/freescale/imx8mm_evk/imx8mm_evk.c), gd->flags |= (GD_FLG_SILENT | GD_FLG_DISABLE_CONSOLE

The only thing that is working is that autoboot has no delay anymore (Hit key ...).

For my question to silent kernel permanently, do you know where to set bootargs ?

Best regards

Re: IMX8MM u-boot and kernel silent

Zhiming_Liu — Fri, 21 Apr 2023 00:41:28 GMT

You can set the console=null in bootargs, the kernel log will not output.

Re: IMX8MM u-boot and kernel silent

baptiste — Fri, 21 Apr 2023 07:52:50 GMT

Hi Qmiller,

I will try, but where ?
In which file ?

Best regards