I’m trying to get u-boot to stop interrupting when there’s serial data so I can use the J21 serial port for communication with another device.
According to the “U-Boot Customization” section in the 28.1 Release of the Development Guide all you have to do is set bootdelay to a negative value.
Contains the number of seconds that U-Boot pauses to determine whether the user wishes to interrupt the boot sequence. To avoid delay, set to 0. Note: Although this value avoids delay, if the user has requested to interrupt the boot process before the U-Boot shell is reached, that request is honored. To avoid a delay and user interruption of the boot process, set bootdelay to a negative value.
I’ve tried to do it through the console using setenv and saveenv, but serial input still interrupts the boot. Even though printenv shows that the value is still set to -1 after power cycling.
I’ve even tried modifying common/autoboot.c to force stored_bootdelay to -1, but still no effect.
How can I make u-boot not interrupt on serial data?