Linux – Configuring TTY Over USB on Headless System

I have an IMX8MM (tx8m-1610) based linux system. I use a usb connection to flash new software on it and then i switch to either the serial debug port or ssh to continue working on the system.

I would like to set the system up in such a way that after flashing a new rootfs or kernel on it, i can simply remove the "boot from usb" jumper, reboot and then have it show up as a usb device through which i can get into the console.

i have

CONFIG_USB_SERIAL=y

CONFIG_USB_SERIAL_CONSOLE=y

CONFIG_USB_SERIAL_GENERIC=y

enabled in the kernel config
and in my dtb the usb device is defined as a peripheral device.

usbg1: usbg1 {
    compatible = "fsl,imx27-usb-gadget";
    chipidea,usb = <&usbotg1>;
    dr_mode = "peripheral";
    status = "okay";
};

&usbotg1 {
    dr_mode = "peripheral";
    status = "okay";
};

&usbotg2 {
    dr_mode = "peripheral";
    status = "okay";
};

i enable and start getty@ttyUSB0

but it still doesn't show up as a usb device.

I can't find much other information sources online.

linux kernel 5.15.32
debian 11 bullseye

edit:

okay i got a little further, i managed to get it working, unfortunately my method required me to run depmod, which means i have to have access to the terminal before i can make it work.

While the goal is to switch from flashing new software to tty over usb without getting into the terminal by some other means inbetween.