• Tobias Klauser's avatar
    nios2: enable earlycon support · 44a4ed42
    Tobias Klauser authored
    Enable generic earlycon support for nios2. This e.g. allows to use a
    8250/16650 UART as earlycon.
    
    In order to get the earlycon, we just need to call parse_early_param()
    in early_init_devtree() as soon as the device tree is initially scanned.
    By adding an stdout-path property to the dts (done in this patch for
    10m50_devboard), the earlycon can be used.
    
    In order to provide early printk support, we need to provide a dummy
    implementation of early_console_write(), so that
    arch/nios2/kernel/early_printk.c can still be compiled if neither
    SERIAL_ALTERA_JTAGUART_CONSOLE nor SERIAL_ALTERA_UART_CONSOLE is
    selected. As soon as the altera_uart and altera_jtaguart support
    earlycon, the entire file can be removed.
    Tested-by: default avatarGuenter Roeck <linux@roeck-us.net>
    Signed-off-by: default avatarTobias Klauser <tklauser@distanz.ch>
    Acked-by: default avatarLey Foon Tan <ley.foon.tan@intel.com>
    44a4ed42
10m50_devboard.dts 5.81 KB