diff options
Diffstat (limited to 'i386/pc/i16/i16_a20.c')
| -rw-r--r-- | i386/pc/i16/i16_a20.c | 144 |
1 files changed, 0 insertions, 144 deletions
diff --git a/i386/pc/i16/i16_a20.c b/i386/pc/i16/i16_a20.c deleted file mode 100644 index 5e91f86..0000000 --- a/i386/pc/i16/i16_a20.c +++ /dev/null @@ -1,144 +0,0 @@ -/* - * Copyright (c) 1995-1994 The University of Utah and - * the Computer Systems Laboratory at the University of Utah (CSL). - * All rights reserved. - * - * Permission to use, copy, modify and distribute this software is hereby - * granted provided that (1) source code retains these copyright, permission, - * and disclaimer notices, and (2) redistributions including binaries - * reproduce the notices in supporting documentation, and (3) all advertising - * materials mentioning features or use of this software display the following - * acknowledgement: ``This product includes software developed by the - * Computer Systems Laboratory at the University of Utah.'' - * - * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS - * IS" CONDITION. THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF - * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. - * - * CSL requests users of this software to return to csl-dist@cs.utah.edu any - * improvements that they make and grant CSL redistribution rights. - * - * Author: Bryan Ford, University of Utah CSL - */ - - -#include <mach/machine/pio.h> -#include <mach/machine/code16.h> - -#include "i16_a20.h" - - -/* Keyboard stuff for turning on the A20 address line (gak!). */ -#define K_RDWR 0x60 /* keyboard data & cmds (read/write) */ -#define K_STATUS 0x64 /* keyboard status (read-only) */ -#define K_CMD 0x64 /* keybd ctlr command (write-only) */ - -#define K_OBUF_FUL 0x01 /* output buffer full */ -#define K_IBUF_FUL 0x02 /* input buffer full */ - -#define KC_CMD_WIN 0xd0 /* read output port */ -#define KC_CMD_WOUT 0xd1 /* write output port */ - -#define KB_ENABLE_A20 0xdf /* Linux and my BIOS uses this, - and I trust them more than Mach 3.0, - but I'd like to know what the difference is - and if it matters. */ - /*0x9f*/ /* enable A20, - enable output buffer full interrupt - enable data line - disable clock line */ -#define KB_DISABLE_A20 0xdd - - -CODE16 - - -/* - This routine ensures that the keyboard command queue is empty - (after emptying the output buffers) - - No timeout is used - if this hangs there is something wrong with - the machine, and we probably couldn't proceed anyway. - XXX should at least die properly -*/ -static void i16_empty_8042(void) -{ - int status; - -retry: - i16_nanodelay(1000); - status = i16_inb(K_STATUS); - - if (status & K_OBUF_FUL) - { - i16_nanodelay(1000); - i16_inb(K_RDWR); - goto retry; - } - - if (status & K_IBUF_FUL) - goto retry; -} - -int i16_raw_test_a20(void); - -/* Enable the A20 address line. */ -void i16_raw_enable_a20(void) -{ - int v; - - /* XXX try int 15h function 24h */ - - if (i16_raw_test_a20()) - return; - - /* PS/2 */ - v = i16_inb(0x92); - i16_nanodelay(1000); - i16_outb(0x92,v | 2); - - if (i16_raw_test_a20()) - return; - - /* AT */ - i16_empty_8042(); - i16_outb(K_CMD, KC_CMD_WOUT); - i16_empty_8042(); - i16_outb(K_RDWR, KB_ENABLE_A20); - i16_empty_8042(); - - /* Wait until the a20 line gets enabled. */ - while (!i16_raw_test_a20()); -} - -/* Disable the A20 address line. */ -void i16_raw_disable_a20(void) -{ - int v; - - if (!i16_raw_test_a20()) - return; - - /* PS/2 */ - v = i16_inb(0x92); - i16_nanodelay(1000); - i16_outb(0x92, v & ~2); - - if (!i16_raw_test_a20()) - return; - - /* AT */ - i16_empty_8042(); - i16_outb(K_CMD, KC_CMD_WOUT); - i16_empty_8042(); - i16_outb(K_RDWR, KB_DISABLE_A20); - i16_empty_8042(); - - /* Wait until the a20 line gets disabled. */ - while (i16_raw_test_a20()); -} - - -void (*i16_enable_a20)(void) = i16_raw_enable_a20; -void (*i16_disable_a20)(void) = i16_raw_disable_a20; - |