core/include/bios.h

   1 /*
   2  * -----------------------------------------------------------------------
   3  *
   4  *   Copyright 1994-2008 H. Peter Anvin - All Rights Reserved
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   9  *   Boston MA 02111-1307, USA; either version 2 of the License, or
  10  *   (at your option) any later version; incorporated herein by reference.
  11  *
  12  * -----------------------------------------------------------------------
  13  *
  14  *
  15  * bios.h
  16  *
  17  * Header file for the BIOS data structures etc.
  18  */
  19
  20 #ifndef _BIOS_H
  21 #define _BIOS_H
  22
  23 #include <sys/io.h>
  24
  25 /*
  26  * Interrupt vectors
  27  */
  28 #define BIOS_timer_hook (4 * 0x1C)
  29 #define fdctab          (4 * 0x1E)
  30 #define fdctab1         fdctab
  31 #define fdctab2         (fdctab + 2)
  32
  33 #define SERIAL_BASE     0x0400  /* Base address for 4 serial ports */
  34 #define BIOS_fbm        0x0413  /* Free Base Memory (kilobytes) */
  35 #define BIOS_page       0x0462  /* Current video page */
  36 #define BIOS_timer      0x046C  /* Timer ticks */
  37 #define BIOS_magic      0x0472  /* BIOS reset magic */
  38 #define BIOS_vidrows    0x0484  /* Number of screen rows */
  39
  40 static inline uint16_t bios_fbm(void)
  41 {
  42         return *(volatile uint16_t *)BIOS_fbm;
  43 }
  44
  45 static inline void set_bios_fbm(uint16_t mem)
  46 {
  47         *(volatile uint16_t *)BIOS_fbm = mem;
  48 }
  49
  50 #define serial_buf_size         4096
  51 #define IO_DELAY_PORT           0x80 /* Invalid port (we hope!) */
  52
  53 static inline void io_delay(void)
  54 {
  55         outb(0x0, IO_DELAY_PORT);
  56         outb(0x0, IO_DELAY_PORT);
  57 }
  58
  59 /*
  60  * Sometimes we need to access screen coordinates as separate 8-bit
  61  * entities and sometimes we need to use them as 16-bit entities. Using
  62  * this structure allows the compiler to do it for us.
  63  */
  64 union screen {
  65         struct {
  66                 uint8_t col;    /* Cursor column for message file */
  67                 uint8_t row;    /* Cursor row for message file */
  68         } b;
  69         uint16_t dx;
  70 };
  71 extern union screen _cursor;
  72 extern union screen _screensize;
  73
  74 #define CursorDX        _cursor.dx
  75 #define CursorCol       _cursor.b.col
  76 #define CursorRow       _cursor.b.row
  77
  78 #define ScreenSize      _screensize.dx
  79 #define VidCols         _screensize.b.col
  80 #define VidRows         _screensize.b.row
  81
  82 /* font.c */
  83 extern void use_font(void);
  84 extern void bios_adjust_screen(void);
  85
  86 /* serirq.c */
  87 extern char *SerialHead;
  88 extern char *SerialTail;
  89
  90 extern void bios_init(void);
  91
  92 static inline uint16_t get_serial_port(uint16_t port)
  93 {
  94     /* Magic array in BIOS memory, contains four entries */
  95     const uint16_t * const serial_ports = (const uint16_t *)SERIAL_BASE;
  96
  97     /*
  98      * If port > 3 then the port is simply the I/O base address
  99      */
 100     if (port > 3)
 101         return port;
 102
 103     /* Get the I/O port from the BIOS */
 104     return serial_ports[port];
 105 }
 106
 107 #endif /* _BIOS_H */