How to see boot messages on uart

I can connect at 115200 serial wit a CP2102, but only get standard login. Is there a way see boot messages and control boot with it?

without knowing which board or OS, here’s a guess
in “/boot/uEnv.txt” there is a string that starts with “cmdline” in this line remove the word “quiet” save the file and reboot.
hope this helps,

Thanks. Beagle Play was left out.

Found in
/boot/firmware/extlinux/extlinux.conf
/opt/u-boot/bb-u-boot-beagleboneai64/emmc-extlinux.conf
/opt/u-boot/bb-u-boot-beagleboneai64/microsd-extlinux.conf
/opt/u-boot/bb-u-boot-beagleboneai64/nvme-extlinux.conf
/opt/u-boot/bb-u-boot-beagleplay/emmc-extlinux.conf
/opt/u-boot/bb-u-boot-beagleplay/microsd-extlinux.conf

remove ‘quiet’ from /boot/firmware/extlinux/extinux.conf
this is the location that is used at boot time.
i didn’t buy the Beagle Play, messing with BeagleV-aHead, has it’s own challenges,
GL