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How to disable uboot couting down feature during serial console

Question asked by Elias Bitbaker on Aug 19, 2019
Latest reply on Oct 1, 2019 by alexander.yakovlev

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Hi,

I have a TWR-LS1021a Eva board and I am using LSDK1906 to build the kernel. My kernel version is 4.19.46

However, I want to disable

"Hit any key to stop autoboot: 0 " this feature every time during boot so I wont be able to access to the u-boot command window.

I did try to disable the tty during the menuconfig and also hacking kernel to make the console logs as less as possible but

still I can see the u-boot counting down during the boot time.

Anyone knows how to disable that counting down feature so no one can access to the u-boot prompt command window?

alexander.yakovlev

Sep 3, 2019 12:41 PM

Correct Answer

"Set this variable to -2 to boot without delay and not check for abort." means, as per my understanding, that U-boot will skip this check and go directly to booting. This does not mean that you will never have access to the u-boot prompt, because

a) this setting can be changed back by modifying E-boot environment variables from Linux, as we already discussed

b) U-boot can boot Linux successfully only if Linux image is present and valid. In case if booting is not possible, U-boot will obviously stop.

See the reply in context

No one else had this question

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alexander.yakovlev

Aug 19, 2019 1:52 PM

The following is said in U-boot documentation, Section 5.10 "U-boot Environment Variables":

bootdelay: After reset, U-Boot will wait this number of seconds before it executes the contents of the bootcmd variable. During this time a countdown is printed, which can be interrupted by pressing any key.
Set this variable to 0 boot without delay. Be careful: depending on the contents of your bootcmd variable, this can prevent you from entering interactive commands again forever!
Set this variable to -1 to disable autoboot. Set this variable to -2 to boot without delay and not check for abort.

To set this variable you can type in U-boot prompt:

setenv bootdelay 0

saveenv

Direct link to mentioned U-boot documentation page:

https://www.denx.de/wiki/view/DULG/UBootEnvVariables

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Elias Bitbaker @ alexander.yakovlev on Aug 19, 2019 2:58 PM

Thanks for the reply. But what if I want to re-enable then later. Is there a way to do all these settings from the linux ?

Another question is how to make this printing messages silent from the console? I did some research on lines people say I need to change the board header file.

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alexander.yakovlev

@ Elias Bitbaker on Aug 26, 2019 10:17 PM

To modify U-boot environment variables from Linux, you have to build two tools fw_printenv and fw_setenv.

Making u-boot fully silent may be a bit tricky - it is known that "setenv silent 1", intended for this, does not make u-boot fully silent, so some minor changes in software may be required.

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Elias Bitbaker @ alexander.yakovlev on Aug 27, 2019 6:19 AM

Thanks for the reply. Would you be able to provide a bit more detail of how to build that two tools fw_printenv and fw_setenv ? are they from the kernel compilation?

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alexander.yakovlev

@ Elias Bitbaker on Aug 27, 2019 10:10 PM

Please search this community by "fw_printenv" keyword. For example, please look this topic:

https://community.nxp.com/thread/488024

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Elias Bitbaker @ alexander.yakovlev on Aug 28, 2019 5:28 PM

Also regarding your previous reply if I set the bootdelay to -2 does that mean I will never have access to the u-boot prompt?

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alexander.yakovlev

@ Elias Bitbaker on Sep 3, 2019 12:41 PM

a) this setting can be changed back by modifying E-boot environment variables from Linux, as we already discussed

b) U-boot can boot Linux successfully only if Linux image is present and valid. In case if booting is not possible, U-boot will obviously stop.

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Elias Bitbaker @ alexander.yakovlev on Sep 26, 2019 5:27 AM

Hi Alex,

After I run "apt-get install u-boot-tools"

then I perform fw_printenv in the linux it tells me that

Cannot parse config file '/etc/fw_env.config': No such file or directory

Have you ever encountered this issue before?

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alexander.yakovlev

@ Elias Bitbaker on Oct 1, 2019 9:49 AM

As I can understand, this file should be created by used and it should reflect actual flash memory configuration.

Please look, for example, this link:

https://github.com/ARM-software/u-boot/blob/master/tools/env/fw_env.config

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9 Replies

alexander.yakovlev Aug 19, 2019 1:52 PM
Mark Correct
Correct Answer
The following is said in U-boot documentation, Section 5.10 "U-boot Environment Variables":

bootdelay: After reset, U-Boot will wait this number of seconds before it executes the contents of the bootcmd variable. During this time a countdown is printed, which can be interrupted by pressing any key.
Set this variable to 0 boot without delay. Be careful: depending on the contents of your bootcmd variable, this can prevent you from entering interactive commands again forever!
Set this variable to -1 to disable autoboot. Set this variable to -2 to boot without delay and not check for abort.

To set this variable you can type in U-boot prompt:
setenv bootdelay 0
saveenv

Direct link to mentioned U-boot documentation page:

https://www.denx.de/wiki/view/DULG/UBootEnvVariables
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- Elias Bitbaker @ alexander.yakovlev on Aug 19, 2019 2:58 PM
  Mark Correct
  Correct Answer
  Thanks for the reply. But what if I want to re-enable then later. Is there a way to do all these settings from the linux ?
  
  Another question is how to make this printing messages silent from the console? I did some research on lines people say I need to change the board header file.
  Like • Show 0 Likes0
  Actions
  - alexander.yakovlev @ Elias Bitbaker on Aug 26, 2019 10:17 PM
    Mark Correct
    Correct Answer
    To modify U-boot environment variables from Linux, you have to build two tools fw_printenv and fw_setenv.
    
    Making u-boot fully silent may be a bit tricky - it is known that "setenv silent 1", intended for this, does not make u-boot fully silent, so some minor changes in software may be required.
    Like • Show 0 Likes0
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    - Elias Bitbaker @ alexander.yakovlev on Aug 27, 2019 6:19 AM
      Mark Correct
      Correct Answer
      Thanks for the reply. Would you be able to provide a bit more detail of how to build that two tools fw_printenv and fw_setenv ? are they from the kernel compilation?
      Like • Show 0 Likes0
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      - alexander.yakovlev @ Elias Bitbaker on Aug 27, 2019 10:10 PM
        Mark Correct
        Correct Answer
        Please search this community by "fw_printenv" keyword. For example, please look this topic:
        
        https://community.nxp.com/thread/488024
        Like • Show 0 Likes0
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        Elias Bitbaker @ alexander.yakovlev on Aug 28, 2019 5:28 PM
        Mark Correct
        Correct Answer
        Also regarding your previous reply if I set the bootdelay to -2 does that mean I will never have access to the u-boot prompt?
        Like • Show 0 Likes0
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        alexander.yakovlev @ Elias Bitbaker on Sep 3, 2019 12:41 PM
        Unmark Correct
        Correct Answer
        "Set this variable to -2 to boot without delay and not check for abort." means, as per my understanding, that U-boot will skip this check and go directly to booting. This does not mean that you will never have access to the u-boot prompt, because
        a) this setting can be changed back by modifying E-boot environment variables from Linux, as we already discussed
        b) U-boot can boot Linux successfully only if Linux image is present and valid. In case if booting is not possible, U-boot will obviously stop.
        Like • Show 0 Likes0
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        Elias Bitbaker @ alexander.yakovlev on Sep 26, 2019 5:27 AM
        Mark Correct
        Correct Answer
        Hi Alex,
        
        After I run "apt-get install u-boot-tools"
        then I perform fw_printenv in the linux it tells me that
        Cannot parse config file '/etc/fw_env.config': No such file or directory
        
        Have you ever encountered this issue before?
        Like • Show 0 Likes0
        Actions
        alexander.yakovlev @ Elias Bitbaker on Oct 1, 2019 9:49 AM
        Mark Correct
        Correct Answer
        As I can understand, this file should be created by used and it should reflect actual flash memory configuration.
        Please look, for example, this link:
        
        https://github.com/ARM-software/u-boot/blob/master/tools/env/fw_env.config
        Like • Show 0 Likes0
        Actions

How to disable uboot couting down feature during serial console

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