From: Simon Glass <sjg@chromium.org> Tweak the documentation to look better when viewed. Use 'write' instead of 'put'. Signed-off-by: Simon Glass <sjg@chromium.org> --- doc/usage/console.rst | 69 ++++++++++++++++++++++--------------------- 1 file changed, 36 insertions(+), 33 deletions(-) diff --git a/doc/usage/console.rst b/doc/usage/console.rst index f624cc58038..d7d41bca187 100644 --- a/doc/usage/console.rst +++ b/doc/usage/console.rst @@ -6,10 +6,10 @@ U-Boot console handling ======================= -HOW THE CONSOLE WORKS? ----------------------- +Introduction +------------ -At system startup U-Boot initializes a serial console. When U-Boot +At system-startup U-Boot initializes a serial console. When U-Boot relocates itself to RAM, all console drivers are initialized (they will register all detected console devices to the system for further use). @@ -17,43 +17,46 @@ use). If not defined in the environment, the first input device is assigned to the 'stdin' file, the first output one to 'stdout' and 'stderr'. -You can use the command "coninfo" to see all registered console +You can use the command `coninfo` to see all registered console devices and their flags. You can assign a standard file (stdin, stdout or stderr) to any device you see in that list simply by assigning its name to the corresponding environment variable. For -example: +example:: - setenv stdin serial <- To use the serial input - setenv stdout video <- To use the video console + # Use the serial input + setenv stdin serial -Do a simple "saveenv" to save the console settings in the environment + # Use the video console + setenv stdout vidconsole + +Do a simple `saveenv` to save the console settings in the environment and get them working on the next startup, too. -HOW CAN I USE STANDARD FILE INTO THE SOURCES? ---------------------------------------------- +How to output text to the console +--------------------------------- You can use the following functions to access the console: -* STDOUT: - putc (to put a char to stdout) - puts (to put a string to stdout) - printf (to format and put a string to stdout) - -* STDIN: - tstc (to test for the presence of a char in stdin) - getc (to get a char from stdin) - -* STDERR: - eputc (to put a char to stderr) - eputs (to put a string to stderr) - eprintf (to format and put a string to stderr) - -* FILE (can be 'stdin', 'stdout', 'stderr'): - fputc (like putc but redirected to a file) - fputs (like puts but redirected to a file) - fprintf (like printf but redirected to a file) - ftstc (like tstc but redirected to a file) - fgetc (like getc but redirected to a file) - -Remember that all FILE-related functions CANNOT be used before -U-Boot relocation (done in 'board_init_r' in `arch/*/lib/board.c`). +stdout + - putc() - write a char to stdout + - puts() - write a string to stdout + - printf() - format and write a string to stdout + +stdin + - tstc() - test for the presence of a char in stdin + - getchar() - get a char from stdin + +stderr + - eputc() - write a char to stderr + - eputs() - write a string to stderr + - eprintf() - format and write a string to stderr + +file ('stdin', 'stdout' or 'stderr') + - fputc() - write a char to a file + - fputs() - write a string to a file + - fprintf() - format and write a string to a file + - ftstc() - test for the presence of a char in file + - fgetc() - get a char from a file + +Remember that FILE-related functions CANNOT be used before U-Boot relocation, +which is done in `board_init_r()`. -- 2.43.0