2 # Serial device configuration
7 config REQUIRE_SERIAL_CONSOLE
8 bool "Require a serial port for console"
9 # Running without a serial console is not supported by the
14 Require a serial port for the console, and panic if none is found
15 during serial port initialization (default y). Set this to n on
16 boards which have no debug serial port whatsoever.
19 bool "Provide a serial driver"
23 In very space-constrained devices even the full UART driver is too
24 large. In this case the debug UART can still be used in some cases.
25 This option enables the full UART in U-Boot, so if is it disabled,
26 the full UART driver will be omitted, thus saving space.
28 config SPL_SERIAL_PRESENT
29 bool "Provide a serial driver in SPL"
33 In very space-constrained devices even the full UART driver is too
34 large. In this case the debug UART can still be used in some cases.
35 This option enables the full UART in SPL, so if is it disabled,
36 the full UART driver will be omitted, thus saving space.
39 bool "Enable Driver Model for serial drivers"
42 Enable driver model for serial. This replaces
43 drivers/serial/serial.c with the serial uclass, which
44 implements serial_putc() etc. The uclass interface is
45 defined in include/serial.h.
48 bool "Enable an early debug UART for debugging"
50 The debug UART is intended for use very early in U-Boot to debug
51 problems when an ICE or other debug mechanism is not available.
54 - Make sure your UART supports this interface
55 - Enable CONFIG_DEBUG_UART
56 - Enable the CONFIG for your UART to tell it to provide this interface
57 (e.g. CONFIG_DEBUG_UART_NS16550)
58 - Define the required settings as needed (see below)
59 - Call debug_uart_init() before use
60 - Call debug_uart_putc() to output a character
62 Depending on your platform it may be possible to use this UART before
65 If your UART does not support this interface you can probably add
66 support quite easily. Remember that you cannot use driver model and
67 it is preferred to use no stack.
69 You must not use this UART once driver model is working and the
70 serial drivers are up and running (done in serial_init()). Otherwise
71 the drivers may conflict and you will get strange output.
74 prompt "Select which UART will provide the debug UART"
76 default DEBUG_UART_NS16550
78 config DEBUG_UART_ALTERA_JTAGUART
79 bool "Altera JTAG UART"
81 Select this to enable a debug UART using the altera_jtag_uart driver.
82 You will need to provide parameters to make this work. The driver will
83 be available until the real driver model serial is running.
85 config DEBUG_UART_ALTERA_UART
88 Select this to enable a debug UART using the altera_uart driver.
89 You will need to provide parameters to make this work. The driver will
90 be available until the real driver model serial is running.
92 config DEBUG_UART_NS16550
95 Select this to enable a debug UART using the ns16550 driver. You
96 will need to provide parameters to make this work. The driver will
97 be available until the real driver model serial is running.
99 config DEBUG_EFI_CONSOLE
103 Select this to enable a debug console which calls back to EFI to
104 output to the console. This can be useful for early debugging of
105 U-Boot when running on top of EFI (Extensive Firmware Interface).
106 This is a type of BIOS used by PCs.
108 config DEBUG_UART_S5P
111 Select this to enable a debug UART using the serial_s5p driver. You
112 will need to provide parameters to make this work. The driver will
113 be available until the real driver-model serial is running.
115 config DEBUG_UART_ZYNQ
118 Select this to enable a debug UART using the serial_zynq driver. You
119 will need to provide parameters to make this work. The driver will
120 be available until the real driver-model serial is running.
122 config DEBUG_UART_APBUART
124 bool "Gaisler APBUART"
126 Select this to enable a debug UART using the serial_leon3 driver. You
127 will need to provide parameters to make this work. The driver will
128 be available until the real driver model serial is running.
132 config DEBUG_UART_BASE
133 hex "Base address of UART"
134 depends on DEBUG_UART
136 This is the base address of your UART for memory-mapped UARTs.
138 A default should be provided by your board, but if not you will need
139 to use the correct value here.
141 config DEBUG_UART_CLOCK
142 int "UART input clock"
143 depends on DEBUG_UART
145 The UART input clock determines the speed of the internal UART
146 circuitry. The baud rate is derived from this by dividing the input
149 A default should be provided by your board, but if not you will need
150 to use the correct value here.
152 config DEBUG_UART_SHIFT
153 int "UART register shift"
154 depends on DEBUG_UART
155 default 0 if DEBUG_UART
157 Some UARTs (notably ns16550) support different register layouts
158 where the registers are spaced either as bytes, words or some other
159 value. Use this value to specify the shift to use, where 0=byte
160 registers, 2=32-bit word registers, etc.
162 config DEBUG_UART_BOARD_INIT
163 bool "Enable board-specific debug UART init"
164 depends on DEBUG_UART
166 Some boards need to set things up before the debug UART can be used.
167 On these boards a call to debug_uart_init() is insufficient. When
168 this option is enabled, the function board_debug_uart_init() will
169 be called when debug_uart_init() is called. You can put any code
170 here that is needed to set up the UART ready for use, such as set
171 pin multiplexing or enable clocks.
173 config DEBUG_UART_ANNOUNCE
174 bool "Show a message when the debug UART starts up"
175 depends on DEBUG_UART
177 Enable this option to show a message when the debug UART is ready
178 for use. You will see a message like "<debug_uart> " as soon as
179 U-Boot has the UART ready for use (i.e. your code calls
180 debug_uart_init()). This can be useful just as a check that
181 everything is working.
183 config ALTERA_JTAG_UART
184 bool "Altera JTAG UART support"
187 Select this to enable an JTAG UART for Altera devices.The JTAG UART
188 core implements a method to communicate serial character streams
189 between a host PC and a Qsys system on an Altera FPGA. Please find
190 details on the "Embedded Peripherals IP User Guide" of Altera.
192 config ALTERA_JTAG_UART_BYPASS
193 bool "Bypass output when no connection"
194 depends on ALTERA_JTAG_UART
196 Bypass console output and keep going even if there is no JTAG
197 terminal connection with the host. The console output will resume
198 once the JTAG terminal is connected. Without the bypass, the console
199 output will wait forever until a JTAG terminal is connected. If you
203 bool "Altera UART support"
206 Select this to enable an UART for Altera devices. Please find
207 details on the "Embedded Peripherals IP User Guide" of Altera.
210 bool "NS16550 UART or compatible"
212 Support NS16550 UART or compatible. This can be enabled in the
213 device tree with the correct input clock frequency. If the input
214 clock frequency is not defined in the device tree, the macro
215 CONFIG_SYS_NS16550_CLK defined in a legacy board header file will
216 be used. It can be a constant or a function to get clock, eg,
219 config SANDBOX_SERIAL
220 bool "Sandbox UART support"
223 Select this to enable a seral UART for sandbox. This is required to
224 operate correctly, otherwise you will see no serial output from
225 sandbox. The emulated UART will display to the console and console
226 input will be fed into the UART. This allows you to interact with
229 The operation of the console is controlled by the -t command-line
230 flag. In raw mode, U-Boot sees all characters from the terminal
231 before they are processed, including Ctrl-C. In cooked mode, Ctrl-C
232 is processed by the terminal, and terminates U-Boot. Valid options
235 -t raw-with-sigs Raw mode, Ctrl-C will terminate U-Boot
236 -t raw Raw mode, Ctrl-C is processed by U-Boot
237 -t cooked Cooked mode, Ctrl-C terminates
239 config UNIPHIER_SERIAL
240 bool "Support for UniPhier on-chip UART"
241 depends on ARCH_UNIPHIER
243 If you have a UniPhier based board and want to use the on-chip
244 serial ports, say Y to this option. If unsure, say N.