linux shell ctrl-C doesn't work (using busybox)

I'm working on an arm64 system ([Arm PL011](https://developer.arm.com/Processors/PL011)) and I have ported linux 5.15.68 using u-boot-spl , busybox. In the past, I could use Ctrl-C in the linux shell by entering setsid cttyhack sh But somehow it doesn't work now. And I also get an error: > can't open /dev/ttyAMA0 There have been some changes but I don't know what has made this change.