grub/commands/i386/pc/play.c
Samuel Thibault 6fa7cfce65 2010-02-14 Samuel Thibault <samuel.thibault@ens-lyon.org>
* commands/i386/pc/play.c (GRUB_MOD_INIT(play)): Fix help.
	* docs/grub.texi (Command-line and menu entry commands): Document play
	command.
2010-02-14 18:36:26 +01:00

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/* play.c - command to play a tune */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2005,2007,2009 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/>.
*/
/* Lots of this file is borrowed from GNU/Hurd generic-speaker driver. */
#include <grub/dl.h>
#include <grub/file.h>
#include <grub/disk.h>
#include <grub/term.h>
#include <grub/misc.h>
#include <grub/machine/time.h>
#include <grub/cpu/io.h>
#include <grub/command.h>
#include <grub/i18n.h>
#define BASE_TEMPO (60 * GRUB_TICKS_PER_SECOND)
/* The speaker port. */
#define SPEAKER 0x61
/* If 0, follow state of SPEAKER_DATA bit, otherwise enable output
from timer 2. */
#define SPEAKER_TMR2 0x01
/* If SPEAKER_TMR2 is not set, this provides direct input into the
speaker. Otherwise, this enables or disables the output from the
timer. */
#define SPEAKER_DATA 0x02
/* The PIT channel value ports. You can write to and read from them.
Do not mess with timer 0 or 1. */
#define PIT_COUNTER_0 0x40
#define PIT_COUNTER_1 0x41
#define PIT_COUNTER_2 0x42
/* The frequency of the PIT clock. */
#define PIT_FREQUENCY 0x1234dd
/* The PIT control port. You can only write to it. Do not mess with
timer 0 or 1. */
#define PIT_CTRL 0x43
#define PIT_CTRL_SELECT_MASK 0xc0
#define PIT_CTRL_SELECT_0 0x00
#define PIT_CTRL_SELECT_1 0x40
#define PIT_CTRL_SELECT_2 0x80
/* Read and load control. */
#define PIT_CTRL_READLOAD_MASK 0x30
#define PIT_CTRL_COUNTER_LATCH 0x00 /* Hold timer value until read. */
#define PIT_CTRL_READLOAD_LSB 0x10 /* Read/load the LSB. */
#define PIT_CTRL_READLOAD_MSB 0x20 /* Read/load the MSB. */
#define PIT_CTRL_READLOAD_WORD 0x30 /* Read/load the LSB then the MSB. */
/* Mode control. */
#define PIT_CTRL_MODE_MASK 0x0e
/* Interrupt on terminal count. Setting the mode sets output to low.
When counter is set and terminated, output is set to high. */
#define PIT_CTRL_INTR_ON_TERM 0x00
/* Programmable one-shot. When loading counter, output is set to
high. When counter terminated, output is set to low. Can be
triggered again from that point on by setting the gate pin to
high. */
#define PIT_CTRL_PROGR_ONE_SHOT 0x02
/* Rate generator. Output is low for one period of the counter, and
high for the other. */
#define PIT_CTRL_RATE_GEN 0x04
/* Square wave generator. Output is low for one half of the period,
and high for the other half. */
#define PIT_CTRL_SQUAREWAVE_GEN 0x06
/* Software triggered strobe. Setting the mode sets output to high.
When counter is set and terminated, output is set to low. */
#define PIT_CTRL_SOFTSTROBE 0x08
/* Hardware triggered strobe. Like software triggered strobe, but
only starts the counter when the gate pin is set to high. */
#define PIT_CTRL_HARDSTROBE 0x0a
/* Count mode. */
#define PIT_CTRL_COUNT_MASK 0x01
#define PIT_CTRL_COUNT_BINARY 0x00 /* 16-bit binary counter. */
#define PIT_CTRL_COUNT_BCD 0x01 /* 4-decade BCD counter. */
#define T_REST ((grub_uint16_t) 0)
#define T_FINE ((grub_uint16_t) -1)
struct note
{
grub_uint16_t pitch;
grub_uint16_t duration;
};
static void
beep_off (void)
{
unsigned char status;
status = grub_inb (SPEAKER);
grub_outb (status & ~(SPEAKER_TMR2 | SPEAKER_DATA), SPEAKER);
}
static void
beep_on (grub_uint16_t pitch)
{
unsigned char status;
unsigned int counter;
if (pitch < 20)
pitch = 20;
else if (pitch > 20000)
pitch = 20000;
counter = PIT_FREQUENCY / pitch;
/* Program timer 2. */
grub_outb (PIT_CTRL_SELECT_2 | PIT_CTRL_READLOAD_WORD
| PIT_CTRL_SQUAREWAVE_GEN | PIT_CTRL_COUNT_BINARY, PIT_CTRL);
grub_outb (counter & 0xff, PIT_COUNTER_2); /* LSB */
grub_outb ((counter >> 8) & 0xff, PIT_COUNTER_2); /* MSB */
/* Start speaker. */
status = grub_inb (SPEAKER);
grub_outb (status | SPEAKER_TMR2 | SPEAKER_DATA, SPEAKER);
}
/* Returns whether playing should continue. */
static int
play (unsigned tempo, struct note *note)
{
unsigned int to;
if (note->pitch == T_FINE || grub_checkkey () >= 0)
return 1;
grub_dprintf ("play", "pitch = %d, duration = %d\n", note->pitch,
note->duration);
switch (note->pitch)
{
case T_REST:
beep_off ();
break;
default:
beep_on (note->pitch);
break;
}
to = grub_get_rtc () + BASE_TEMPO * note->duration / tempo;
while (((unsigned int) grub_get_rtc () <= to) && (grub_checkkey () < 0))
;
return 0;
}
static grub_err_t
grub_cmd_play (grub_command_t cmd __attribute__ ((unused)),
int argc, char **args)
{
grub_file_t file;
if (argc < 1)
return grub_error (GRUB_ERR_BAD_ARGUMENT, "file name or tempo and notes required");
file = grub_file_open (args[0]);
if (file)
{
struct note buf;
grub_uint32_t tempo;
if (grub_file_read (file, &tempo, sizeof (tempo)) != sizeof (tempo))
{
grub_file_close (file);
return grub_error (GRUB_ERR_FILE_READ_ERROR,
"file doesn't even contains a full tempo record");
}
tempo = grub_le_to_cpu32 (tempo);
grub_dprintf ("play","tempo = %d\n", tempo);
while (grub_file_read (file, &buf,
sizeof (struct note)) == sizeof (struct note))
{
buf.pitch = grub_le_to_cpu16 (buf.pitch);
buf.duration = grub_le_to_cpu16 (buf.duration);
if (play (tempo, &buf))
break;
}
grub_file_close (file);
}
else
{
char *end;
unsigned tempo;
struct note note;
int i;
tempo = grub_strtoul (args[0], &end, 0);
if (*end)
/* Was not a number either, assume it was supposed to be a file name. */
return grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
grub_dprintf ("play","tempo = %d\n", tempo);
for (i = 1; i + 1 < argc; i += 2)
{
note.pitch = grub_strtoul (args[i], &end, 0);
if (*end)
{
grub_error (GRUB_ERR_BAD_NUMBER, "bogus pitch number");
break;
}
note.duration = grub_strtoul (args[i + 1], &end, 0);
if (*end)
{
grub_error (GRUB_ERR_BAD_NUMBER, "bogus duration number");
break;
}
if (play (tempo, &note))
break;
}
}
beep_off ();
while (grub_checkkey () > 0)
grub_getkey ();
return 0;
}
static grub_command_t cmd;
GRUB_MOD_INIT(play)
{
cmd = grub_register_command ("play", grub_cmd_play,
N_("FILE | TEMPO [PITCH1 DURATION1] [PITCH2 DURATION2] ... "),
N_("Play a tune."));
}
GRUB_MOD_FINI(play)
{
grub_unregister_command (cmd);
}