When set CONFIG_SERIAL_EARLYCON=y and CONFIG_SERIAL_CORE=m, there is a compile error as below: ld: vmlinux.o: in function `parse_options.constprop.0': earlycon.c:(.init.text+0xba5a3): undefined reference to `uart_parse_earlycon' Since the SERIAL_EARLYCON use 'uart_parse_earlycon' which defined in SERIAL_CORE, so should select rather than depends on. Fixes: 9aac5887595b ("tty/serial: add generic serial earlycon") Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@xxxxxxxxxx> --- drivers/tty/serial/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 434f83168546..803f3dae793c 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -8,7 +8,7 @@ menu "Serial drivers" config SERIAL_EARLYCON bool - depends on SERIAL_CORE + select SERIAL_CORE help Support for early consoles with the earlycon parameter. This enables the console before standard serial driver is probed. The console is -- 2.31.1