Why doesn't U-Boot disable the console output

Question

I have this system which is accessed by a serial Debug Port. I want to disable all of the output, that was made during the U-Boot boot. Therefore there is the

setenv silent 1

parameter, which i put into the BOOTCMD string like:

#define CONFIG_BOOTCOMMAND " setenv silent 1;" \

"bootm "

and there is the

#define CONFIG_SILENT_CONSOLE

command, neither one is working (the lines printed out are still the same and the boot time didn't change). Does somebody see the error ?

Answer 1

U-Boot is doing exactly what it should (silencing the output) with the following command:

#define CONFIG_EXTRA_ENV_SETTINGS \

        "silent=1\0" \

---

see also

Answer 2

For my target, U-Boot baseline 2013.10, silent environment variable works at kernel boot time, but it needed more defines:

#define CONFIG_SILENT_CONSOLE 
#define CONFIG_SYS_DEVICE_NULLDEV
#define CONFIG_SILENT_CONSOLE_UPDATE_ON_SET

That also killed kernel serial console after successful boot, until I added

#define CONFIG_SILENT_U_BOOT_ONLY

Refer to README.silent for more info.