grub/grub-core/term/at_keyboard.c
Michael Bideau 33203ca348 at_keyboard: Fix unreliable key presses
This patch fixes an issue that prevented the at_keyboard module to work
(for me). The cause was a bad/wrong return value in the
grub_at_keyboard_getkey() function in grub-core/term/at_keyboard.c file
at line 237. My symptoms were to have an unresponsive keyboard. Keys
needed to be pressed 10x and more to effectively be printed sometimes
generating multiple key presses (after 1 or 2 sec of no printing). It
was very problematic when typing passphrase in early stage (with
GRUB_ENABLE_CRYPTODISK). When switched to "console" terminal input
keyboard worked perfectly. It also worked great with the GRUB 2.02
packaged by Debian (2.02+dfsg1-20). It was not an output issue but an
input one.

I've managed to analyze the issue and found that it came from the commit
216950a4e (at_keyboard: Split protocol from controller code.). Three
lines where moved from the fetch_key() function in
grub-core/term/at_keyboard.c file to the beginning of
grub_at_keyboard_getkey() function (same file). However, returning -1
made sense when it happened in fetch_key() function but not anymore in
grub_at_keyboard_getkey() function which should return GRUB_TERM_NO_KEY.
I think it was just an incomplete cut-paste missing a small manual
correction. Let's fix it.

Note: Commit message updated by Daniel Kiper.

Signed-off-by: Michael Bideau <mica.devel@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2019-10-21 14:07:47 +02:00

332 lines
8.1 KiB
C

/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2007,2008,2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/dl.h>
#include <grub/at_keyboard.h>
#include <grub/cpu/at_keyboard.h>
#include <grub/cpu/io.h>
#include <grub/misc.h>
#include <grub/term.h>
#include <grub/time.h>
#include <grub/loader.h>
#include <grub/ps2.h>
GRUB_MOD_LICENSE ("GPLv3+");
static grub_uint8_t grub_keyboard_controller_orig;
static grub_uint8_t grub_keyboard_orig_set;
struct grub_ps2_state ps2_state;
static int ping_sent;
static void
grub_keyboard_controller_init (void);
static void
keyboard_controller_wait_until_ready (void)
{
/* 50 us would be enough but our current time resolution is 1ms. */
grub_millisleep (1);
while (! KEYBOARD_COMMAND_ISREADY (grub_inb (KEYBOARD_REG_STATUS)));
}
static grub_uint8_t
wait_ack (void)
{
grub_uint64_t endtime;
grub_uint8_t ack;
endtime = grub_get_time_ms () + 20;
do {
keyboard_controller_wait_until_ready ();
ack = grub_inb (KEYBOARD_REG_DATA);
} while (ack != GRUB_AT_ACK && ack != GRUB_AT_NACK
&& grub_get_time_ms () < endtime);
return ack;
}
static int
at_command (grub_uint8_t data)
{
unsigned i;
for (i = 0; i < GRUB_AT_TRIES; i++)
{
grub_uint8_t ack;
keyboard_controller_wait_until_ready ();
grub_outb (data, KEYBOARD_REG_STATUS);
ack = wait_ack ();
if (ack == GRUB_AT_NACK)
continue;
if (ack == GRUB_AT_ACK)
break;
return 0;
}
return (i != GRUB_AT_TRIES);
}
static void
grub_keyboard_controller_write (grub_uint8_t c)
{
at_command (KEYBOARD_COMMAND_WRITE);
keyboard_controller_wait_until_ready ();
grub_outb (c, KEYBOARD_REG_DATA);
}
#if defined (GRUB_MACHINE_MIPS_LOONGSON) || defined (GRUB_MACHINE_QEMU) || defined (GRUB_MACHINE_COREBOOT) || defined (GRUB_MACHINE_MIPS_QEMU_MIPS)
#define USE_SCANCODE_SET 1
#else
#define USE_SCANCODE_SET 0
#endif
#if !USE_SCANCODE_SET
static grub_uint8_t
grub_keyboard_controller_read (void)
{
at_command (KEYBOARD_COMMAND_READ);
keyboard_controller_wait_until_ready ();
return grub_inb (KEYBOARD_REG_DATA);
}
#endif
static int
write_mode (int mode)
{
unsigned i;
for (i = 0; i < GRUB_AT_TRIES; i++)
{
grub_uint8_t ack;
keyboard_controller_wait_until_ready ();
grub_outb (0xf0, KEYBOARD_REG_DATA);
keyboard_controller_wait_until_ready ();
grub_outb (mode, KEYBOARD_REG_DATA);
keyboard_controller_wait_until_ready ();
ack = wait_ack ();
if (ack == GRUB_AT_NACK)
continue;
if (ack == GRUB_AT_ACK)
break;
return 0;
}
return (i != GRUB_AT_TRIES);
}
static int
query_mode (void)
{
grub_uint8_t ret;
int e;
e = write_mode (0);
if (!e)
return 0;
do {
keyboard_controller_wait_until_ready ();
ret = grub_inb (KEYBOARD_REG_DATA);
} while (ret == GRUB_AT_ACK);
/* QEMU translates the set even in no-translate mode. */
if (ret == 0x43 || ret == 1)
return 1;
if (ret == 0x41 || ret == 2)
return 2;
if (ret == 0x3f || ret == 3)
return 3;
return 0;
}
static void
set_scancodes (void)
{
/* You must have visited computer museum. Keyboard without scancode set
knowledge. Assume XT. */
if (!grub_keyboard_orig_set)
{
grub_dprintf ("atkeyb", "No sets support assumed\n");
ps2_state.current_set = 1;
return;
}
#if !USE_SCANCODE_SET
ps2_state.current_set = 1;
return;
#else
grub_keyboard_controller_write (grub_keyboard_controller_orig
& ~KEYBOARD_AT_TRANSLATE
& ~KEYBOARD_AT_DISABLE);
keyboard_controller_wait_until_ready ();
grub_outb (KEYBOARD_COMMAND_ENABLE, KEYBOARD_REG_DATA);
write_mode (2);
ps2_state.current_set = query_mode ();
grub_dprintf ("atkeyb", "returned set %d\n", ps2_state.current_set);
if (ps2_state.current_set == 2)
return;
write_mode (1);
ps2_state.current_set = query_mode ();
grub_dprintf ("atkeyb", "returned set %d\n", ps2_state.current_set);
if (ps2_state.current_set == 1)
return;
grub_dprintf ("atkeyb", "no supported scancode set found\n");
#endif
}
static void
keyboard_controller_led (grub_uint8_t leds)
{
keyboard_controller_wait_until_ready ();
grub_outb (0xed, KEYBOARD_REG_DATA);
keyboard_controller_wait_until_ready ();
grub_outb (leds & 0x7, KEYBOARD_REG_DATA);
}
int
grub_at_keyboard_is_alive (void)
{
if (ps2_state.current_set != 0)
return 1;
if (ping_sent
&& KEYBOARD_COMMAND_ISREADY (grub_inb (KEYBOARD_REG_STATUS))
&& grub_inb (KEYBOARD_REG_DATA) == 0x55)
{
grub_keyboard_controller_init ();
return 1;
}
if (KEYBOARD_COMMAND_ISREADY (grub_inb (KEYBOARD_REG_STATUS)))
{
grub_outb (0xaa, KEYBOARD_REG_STATUS);
ping_sent = 1;
}
return 0;
}
/* If there is a character pending, return it;
otherwise return GRUB_TERM_NO_KEY. */
static int
grub_at_keyboard_getkey (struct grub_term_input *term __attribute__ ((unused)))
{
grub_uint8_t at_key;
int ret;
grub_uint8_t old_led;
if (!grub_at_keyboard_is_alive ())
return GRUB_TERM_NO_KEY;
if (! KEYBOARD_ISREADY (grub_inb (KEYBOARD_REG_STATUS)))
return GRUB_TERM_NO_KEY;
at_key = grub_inb (KEYBOARD_REG_DATA);
old_led = ps2_state.led_status;
ret = grub_ps2_process_incoming_byte (&ps2_state, at_key);
if (old_led != ps2_state.led_status)
keyboard_controller_led (ps2_state.led_status);
return ret;
}
static void
grub_keyboard_controller_init (void)
{
ps2_state.at_keyboard_status = 0;
/* Drain input buffer. */
while (1)
{
keyboard_controller_wait_until_ready ();
if (! KEYBOARD_ISREADY (grub_inb (KEYBOARD_REG_STATUS)))
break;
keyboard_controller_wait_until_ready ();
grub_inb (KEYBOARD_REG_DATA);
}
#if defined (GRUB_MACHINE_MIPS_LOONGSON) || defined (GRUB_MACHINE_MIPS_QEMU_MIPS)
grub_keyboard_controller_orig = 0;
grub_keyboard_orig_set = 2;
#elif defined (GRUB_MACHINE_QEMU) || defined (GRUB_MACHINE_COREBOOT)
/* *BSD relies on those settings. */
grub_keyboard_controller_orig = KEYBOARD_AT_TRANSLATE;
grub_keyboard_orig_set = 2;
#else
grub_keyboard_controller_orig = grub_keyboard_controller_read ();
grub_keyboard_orig_set = query_mode ();
#endif
set_scancodes ();
keyboard_controller_led (ps2_state.led_status);
}
static grub_err_t
grub_keyboard_controller_fini (struct grub_term_input *term __attribute__ ((unused)))
{
if (ps2_state.current_set == 0)
return GRUB_ERR_NONE;
if (grub_keyboard_orig_set)
write_mode (grub_keyboard_orig_set);
grub_keyboard_controller_write (grub_keyboard_controller_orig);
return GRUB_ERR_NONE;
}
static grub_err_t
grub_at_fini_hw (int noreturn __attribute__ ((unused)))
{
return grub_keyboard_controller_fini (NULL);
}
static grub_err_t
grub_at_restore_hw (void)
{
if (ps2_state.current_set == 0)
return GRUB_ERR_NONE;
/* Drain input buffer. */
while (1)
{
keyboard_controller_wait_until_ready ();
if (! KEYBOARD_ISREADY (grub_inb (KEYBOARD_REG_STATUS)))
break;
keyboard_controller_wait_until_ready ();
grub_inb (KEYBOARD_REG_DATA);
}
set_scancodes ();
keyboard_controller_led (ps2_state.led_status);
return GRUB_ERR_NONE;
}
static struct grub_term_input grub_at_keyboard_term =
{
.name = "at_keyboard",
.fini = grub_keyboard_controller_fini,
.getkey = grub_at_keyboard_getkey
};
GRUB_MOD_INIT(at_keyboard)
{
grub_term_register_input ("at_keyboard", &grub_at_keyboard_term);
grub_loader_register_preboot_hook (grub_at_fini_hw, grub_at_restore_hw,
GRUB_LOADER_PREBOOT_HOOK_PRIO_CONSOLE);
}
GRUB_MOD_FINI(at_keyboard)
{
grub_keyboard_controller_fini (NULL);
grub_term_unregister_input (&grub_at_keyboard_term);
}