src/include/console.h

   1 #ifndef CONSOLE_H
   2 #define CONSOLE_H
   3
   4 #include <gpxe/tables.h>
   5
   6 /** @file
   7  *
   8  * User interaction.
   9  *
  10  * Various console devices can be selected via the build options
  11  * CONSOLE_FIRMWARE, CONSOLE_SERIAL etc.  The console functions
  12  * putchar(), getchar() and iskey() delegate to the individual console
  13  * drivers.
  14  *
  15  */
  16
  17 /**
  18  * A console driver
  19  *
  20  * Defines the functions that implement a particular console type.
  21  * Must be made part of the console drivers table by using
  22  * #__console_driver.
  23  *
  24  * @note Consoles that cannot be used before their initialisation
  25  * function has completed should set #disabled=1 initially.  This
  26  * allows other console devices to still be used to print out early
  27  * debugging messages.
  28  *
  29  */
  30 struct console_driver {
  31         /** Console is disabled.
  32          *
  33          * The console's putchar(), putline(), getchar() and iskey()
  34          * methods will not be called while #disabled==1. Typically
  35          * the console's initialisation functions will set #disabled=0
  36          * upon completion.
  37          *
  38          */
  39         int disabled;
  40
  41         /** Write a character to the console.
  42          *
  43          * @v character         Character to be written
  44          * @ret None            -
  45          * @err None            -
  46          *
  47          */
  48         void ( *putchar ) ( int character );
  49
  50         /** Write an entire line to the console.
  51          * This is intended to be used by line-oriented output media,
  52          * like system logging facilities or line printers.
  53          * Line output will not contain non-printable characters.
  54          *
  55          * @v linebuffer        Pointer to the \0-terminated line
  56          * @ret None            -
  57          * @err None            -
  58          */
  59         void ( * putline ) ( unsigned char * linebuffer );
  60
  61         /** Read a character from the console.
  62          *
  63          * @v None              -
  64          * @ret character       Character read
  65          * @err None            -
  66          *
  67          * If no character is available to be read, this method will
  68          * block.  The character read should not be echoed back to the
  69          * console.
  70          *
  71          */
  72         int ( *getchar ) ( void );
  73
  74         /** Check for available input.
  75          *
  76          * @v None              -
  77          * @ret True            Input is available
  78          * @ret False           Input is not available
  79          * @err None            -
  80          *
  81          * This should return True if a subsequent call to getchar()
  82          * will not block.
  83          *
  84          */
  85         int ( *iskey ) ( void );
  86 };
  87
  88 /**
  89  * Mark a <tt> struct console_driver </tt> as being part of the
  90  * console drivers table.
  91  *
  92  * Use as e.g.
  93  *
  94  * @code
  95  *
  96  *   struct console_driver my_console __console_driver = {
  97  *      .putchar = my_putchar,
  98  *      .getchar = my_getchar,
  99  *      .iskey = my_iskey,
 100  *   };
 101  *
 102  * @endcode
 103  *
 104  */
 105 #define __console_driver __table ( struct console_driver, console, 01 )
 106
 107 /* Function prototypes */
 108
 109 extern void putchar ( int character );
 110 extern int getchar ( void );
 111 extern int iskey ( void );
 112 extern int getkey ( void );
 113
 114 #endif /* CONSOLE_H */