# # Serial device configuration # menu "Serial drivers" config REQUIRE_SERIAL_CONSOLE bool "Require a serial port for console" # Running without a serial console is not supported by the # non-dm serial code depends on DM_SERIAL default y help Require a serial port for the console, and panic if none is found during serial port initialization (default y). Set this to n on boards which have no debug serial port whatsoever. config DM_SERIAL bool "Enable Driver Model for serial drivers" depends on DM help Enable driver model for serial. This replaces drivers/serial/serial.c with the serial uclass, which implements serial_putc() etc. The uclass interface is defined in include/serial.h. config DEBUG_UART bool "Enable an early debug UART for debugging" help The debug UART is intended for use very early in U-Boot to debug problems when an ICE or other debug mechanism is not available. To use it you should: - Make sure your UART supports this interface - Enable CONFIG_DEBUG_UART - Enable the CONFIG for your UART to tell it to provide this interface (e.g. CONFIG_DEBUG_UART_NS16550) - Define the required settings as needed (see below) - Call debug_uart_init() before use - Call debug_uart_putc() to output a character Depending on your platform it may be possible to use this UART before a stack is available. If your UART does not support this interface you can probably add support quite easily. Remember that you cannot use driver model and it is preferred to use no stack. You must not use this UART once driver model is working and the serial drivers are up and running (done in serial_init()). Otherwise the drivers may conflict and you will get strange output. choice prompt "Select which UART will provide the debug UART" depends on DEBUG_UART config DEBUG_UART_NS16550 bool "ns16550" help Select this to enable a debug UART using the ns16550 driver. You will need to provide parameters to make this work. The driver will be available until the real driver model serial is running. config DEBUG_EFI_CONSOLE bool "EFI" depends on EFI_APP help Select this to enable a debug console which calls back to EFI to output to the console. This can be useful for early debugging of U-Boot when running on top of EFI (Extensive Firmware Interface). This is a type of BIOS used by PCs. config DEBUG_UART_S5P bool "Samsung S5P" help Select this to enable a debug UART using the serial_s5p driver. You will need to provide parameters to make this work. The driver will be available until the real driver-model serial is running. endchoice config DEBUG_UART_BASE hex "Base address of UART" depends on DEBUG_UART help This is the base address of your UART for memory-mapped UARTs. A default should be provided by your board, but if not you will need to use the correct value here. config DEBUG_UART_CLOCK int "UART input clock" depends on DEBUG_UART help The UART input clock determines the speed of the internal UART circuitry. The baud rate is derived from this by dividing the input clock down. A default should be provided by your board, but if not you will need to use the correct value here. config DEBUG_UART_SHIFT int "UART register shift" depends on DEBUG_UART default 0 if DEBUG_UART help Some UARTs (notably ns16550) support different register layouts where the registers are spaced either as bytes, words or some other value. Use this value to specify the shift to use, where 0=byte registers, 2=32-bit word registers, etc. config SANDBOX_SERIAL bool "Sandbox UART support" depends on SANDBOX && DM help Select this to enable a seral UART for sandbox. This is required to operate correctly, otherwise you will see no serial output from sandbox. The emulated UART will display to the console and console input will be fed into the UART. This allows you to interact with U-Boot. The operation of the console is controlled by the -t command-line flag. In raw mode, U-Boot sees all characters from the terminal before they are processed, including Ctrl-C. In cooked mode, Ctrl-C is processed by the terminal, and terminates U-Boot. Valid options are: -t raw-with-sigs Raw mode, Ctrl-C will terminate U-Boot -t raw Raw mode, Ctrl-C is processed by U-Boot -t cooked Cooked mode, Ctrl-C terminates config UNIPHIER_SERIAL bool "Support for UniPhier on-chip UART" depends on ARCH_UNIPHIER && DM_SERIAL help If you have a UniPhier based board and want to use the on-chip serial ports, say Y to this option. If unsure, say N. config X86_SERIAL bool "Support for 16550 serial port on x86 machines" depends on X86 default y help Most x86 machines have a ns16550 UART or compatible. This can be enabled in the device tree with the correct input clock frequency provided (default 1843200). Enable this to obtain serial console output. endmenu