From ded439de5b72d33474f96fbc08b9687a76c938ac Mon Sep 17 00:00:00 2001

From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>

Date: Wed, 16 Jan 2013 20:39:54 +0100

Subject: [PATCH 111/482] 	New terminal outputs using serial: morse and

 spkmodem.

---

 ChangeLog                         |   4 ++

 docs/grub.texi                    |  24 +++++--

 grub-core/Makefile.core.def       |  12 ++++

 grub-core/commands/i386/pc/play.c | 109 ++-----------------------------

 grub-core/kern/i386/pit.c         |  35 ++++------

 grub-core/term/morse.c            | 131 ++++++++++++++++++++++++++++++++++++++

 grub-core/term/spkmodem.c         | 106 ++++++++++++++++++++++++++++++

 include/grub/i386/pit.h           |  78 +++++++++++++++++++++++

 include/grub/speaker.h            |  47 ++++++++++++++

 util/spkmodem-recv.c              |  98 ++++++++++++++++++++++++++++

 10 files changed, 512 insertions(+), 132 deletions(-)

 create mode 100644 grub-core/term/morse.c

 create mode 100644 grub-core/term/spkmodem.c

 create mode 100644 include/grub/speaker.h

 create mode 100644 util/spkmodem-recv.c

diff --git a/ChangeLog b/ChangeLog

index 96aca66..f1c53e3 100644

--- a/ChangeLog

+++ b/ChangeLog

@@ -1,5 +1,9 @@

 2013-01-16  Vladimir Serbinenko  <phcoder@gmail.com>

+	New terminal outputs using serial: morse and spkmodem.

+

+2013-01-16  Vladimir Serbinenko  <phcoder@gmail.com>

+

 	Improve bidi handling in entry editor.

 2013-01-16  Vladimir Serbinenko  <phcoder@gmail.com>

diff --git a/docs/grub.texi b/docs/grub.texi

index e75bae9..efedd27 100644

--- a/docs/grub.texi

+++ b/docs/grub.texi

@@ -1229,9 +1229,9 @@ Select the terminal input device.  You may select multiple devices here,

 separated by spaces.

 Valid terminal input names depend on the platform, but may include

-@samp{console} (PC BIOS and EFI consoles), @samp{serial} (serial terminal),

-@samp{ofconsole} (Open Firmware console), @samp{at_keyboard} (PC AT

-keyboard, mainly useful with Coreboot), or @samp{usb_keyboard} (USB keyboard

+@samp{console} (native platform console), @samp{serial} (serial terminal),

+@samp{serial_<port>} (serial terminal with explicit port selection),

+@samp{at_keyboard} (PC AT keyboard), or @samp{usb_keyboard} (USB keyboard

 using the HID Boot Protocol, for cases where the firmware does not handle

 this).

@@ -1242,9 +1242,21 @@ Select the terminal output device.  You may select multiple devices here,

 separated by spaces.

 Valid terminal output names depend on the platform, but may include

-@samp{console} (PC BIOS and EFI consoles), @samp{serial} (serial terminal),

-@samp{gfxterm} (graphics-mode output), @samp{ofconsole} (Open Firmware

-console), or @samp{vga_text} (VGA text output, mainly useful with Coreboot).

+@samp{console} (native platform console), @samp{serial} (serial terminal),

+@samp{serial_<port>} (serial terminal with explicit port selection),

+@samp{gfxterm} (graphics-mode output), @samp{vga_text} (VGA text output),

+@samp{mda_text} (MDA text output), @samp{morse} (Morse-coding using system

+beeper) or @samp{spkmodem} (simple data protocol using system speaker).

+

+@samp{spkmodem} is useful when no serial port is available. Connect the output

+of sending system (where GRUB is running) to line-in of receiving system

+(usually developper machine).

+On receiving system compile @samp{spkmodem-recv} from

+@samp{util/spkmodem-recv.c} and run:

+

+@example

+parecord --channels=1 --rate=48000 --format=s16le | ./spkmodem-recv

+@end example

 The default is to use the platform's native terminal output.

diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def

index f4dd645..baf80b8 100644

--- a/grub-core/Makefile.core.def

+++ b/grub-core/Makefile.core.def

@@ -779,6 +779,18 @@ module = {

 };

 module = {

+  name = spkmodem;

+  x86 = term/spkmodem.c;

+  enable = x86;

+};

+

+module = {

+  name = morse;

+  x86 = term/morse.c;

+  enable = x86;

+};

+

+module = {

   name = probe;

   common = commands/probe.c;

 };

diff --git a/grub-core/commands/i386/pc/play.c b/grub-core/commands/i386/pc/play.c

index 10a0181..40798c9 100644

--- a/grub-core/commands/i386/pc/play.c

+++ b/grub-core/commands/i386/pc/play.c

@@ -28,80 +28,12 @@

 #include <grub/command.h>

 #include <grub/i18n.h>

 #include <grub/time.h>

+#include <grub/speaker.h>

 GRUB_MOD_LICENSE ("GPLv3+");

 #define BASE_TEMPO (60 * 1000)

-/* 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)

@@ -112,39 +44,6 @@ struct note

   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)

@@ -160,11 +59,11 @@ play (unsigned tempo, struct note *note)

   switch (note->pitch)

     {

       case T_REST:

-        beep_off ();

+        grub_speaker_beep_off ();

         break;

       default:

-        beep_on (note->pitch);

+        grub_speaker_beep_on (note->pitch);

         break;

     }

@@ -263,7 +162,7 @@ grub_cmd_play (grub_command_t cmd __attribute__ ((unused)),

         }

     }

-  beep_off ();

+  grub_speaker_beep_off ();

   return 0;

 }

diff --git a/grub-core/kern/i386/pit.c b/grub-core/kern/i386/pit.c

index 82a17d3..092481a 100644

--- a/grub-core/kern/i386/pit.c

+++ b/grub-core/kern/i386/pit.c

@@ -20,37 +20,30 @@

 #include <grub/i386/io.h>

 #include <grub/i386/pit.h>

-#define TIMER2_REG_CONTROL	0x42

-#define TIMER_REG_COMMAND	0x43

-#define TIMER2_REG_LATCH	0x61

-

-#define TIMER2_SELECT		0x80

-#define TIMER_ENABLE_LSB	0x20

-#define TIMER_ENABLE_MSB	0x10

-#define TIMER2_LATCH		0x20

-#define TIMER2_SPEAKER		0x02

-#define TIMER2_GATE		0x01

-

 void

 grub_pit_wait (grub_uint16_t tics)

 {

   /* Disable timer2 gate and speaker.  */

-  grub_outb (grub_inb (TIMER2_REG_LATCH) & ~ (TIMER2_SPEAKER | TIMER2_GATE),

-             TIMER2_REG_LATCH);

+  grub_outb (grub_inb (GRUB_PIT_SPEAKER_PORT)

+	     & ~ (GRUB_PIT_SPK_DATA | GRUB_PIT_SPK_TMR2),

+             GRUB_PIT_SPEAKER_PORT);

   /* Set tics.  */

-  grub_outb (TIMER2_SELECT | TIMER_ENABLE_LSB | TIMER_ENABLE_MSB, TIMER_REG_COMMAND);

-  grub_outb (tics & 0xff, TIMER2_REG_CONTROL);

-  grub_outb (tics >> 8, TIMER2_REG_CONTROL);

+  grub_outb (GRUB_PIT_CTRL_SELECT_2 | GRUB_PIT_CTRL_READLOAD_WORD,

+	     GRUB_PIT_CTRL);

+  grub_outb (tics & 0xff, GRUB_PIT_COUNTER_2);

+  grub_outb (tics >> 8, GRUB_PIT_COUNTER_2);

   /* Enable timer2 gate, keep speaker disabled.  */

-  grub_outb ((grub_inb (TIMER2_REG_LATCH) & ~ TIMER2_SPEAKER) | TIMER2_GATE,

-             TIMER2_REG_LATCH);

+  grub_outb ((grub_inb (GRUB_PIT_SPEAKER_PORT) & ~ GRUB_PIT_SPK_DATA)

+	     | GRUB_PIT_SPK_TMR2,

+             GRUB_PIT_SPEAKER_PORT);

   /* Wait.  */

-  while ((grub_inb (TIMER2_REG_LATCH) & TIMER2_LATCH) == 0x00);

+  while ((grub_inb (GRUB_PIT_SPEAKER_PORT) & GRUB_PIT_SPK_TMR2_LATCH) == 0x00);

   /* Disable timer2 gate and speaker.  */

-  grub_outb (grub_inb (TIMER2_REG_LATCH) & ~ (TIMER2_SPEAKER | TIMER2_GATE),

-             TIMER2_REG_LATCH);

+  grub_outb (grub_inb (GRUB_PIT_SPEAKER_PORT)

+	     & ~ (GRUB_PIT_SPK_DATA | GRUB_PIT_SPK_TMR2),

+             GRUB_PIT_SPEAKER_PORT);

 }

diff --git a/grub-core/term/morse.c b/grub-core/term/morse.c

new file mode 100644

index 0000000..3d6c650

--- /dev/null

+++ b/grub-core/term/morse.c

@@ -0,0 +1,131 @@

+/*

+ *  GRUB  --  GRand Unified Bootloader

+ *  Copyright (C) 2011,2012,2013  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/term.h>

+#include <grub/misc.h>

+#include <grub/types.h>

+#include <grub/err.h>

+#include <grub/dl.h>

+#include <grub/time.h>

+#include <grub/speaker.h>

+

+GRUB_MOD_LICENSE ("GPLv3+");

+

+#define BASE_TIME 250

+

+static const char codes[0x80][6] =

+  {

+    ['0'] = { 3, 3, 3, 3, 3, 0 },

+    ['1'] = { 1, 3, 3, 3, 3, 0 },

+    ['2'] = { 1, 1, 3, 3, 3, 0 },

+    ['3'] = { 1, 1, 1, 3, 3, 0 },

+    ['4'] = { 1, 1, 1, 1, 3, 0 },

+    ['5'] = { 1, 1, 1, 1, 1, 0 },

+    ['6'] = { 3, 1, 1, 1, 1, 0 },

+    ['7'] = { 3, 3, 1, 1, 1, 0 },

+    ['8'] = { 3, 3, 3, 1, 1, 0 },

+    ['9'] = { 3, 3, 3, 3, 1, 0 },

+    ['a'] = { 1, 3, 0 },

+    ['b'] = { 3, 1, 1, 1, 0 },

+    ['c'] = { 3, 1, 3, 1, 0 },

+    ['d'] = { 3, 1, 1, 0 },

+    ['e'] = { 1, 0 },

+    ['f'] = { 1, 1, 3, 1, 0 },

+    ['g'] = { 3, 3, 1, 0 },

+    ['h'] = { 1, 1, 1, 1, 0 },

+    ['i'] = { 1, 1, 0 },

+    ['j'] = { 1, 3, 3, 3, 0 },

+    ['k'] = { 3, 1, 3, 0 },

+    ['l'] = { 1, 3, 1, 1, 0 },

+    ['m'] = { 3, 3, 0 },

+    ['n'] = { 3, 1, 0 },

+    ['o'] = { 3, 3, 3, 0 },

+    ['p'] = { 1, 3, 3, 1, 0 },

+    ['q'] = { 3, 3, 1, 3, 0 },

+    ['r'] = { 1, 3, 1, 0 },

+    ['s'] = { 1, 1, 1, 0 },

+    ['t'] = { 3, 0 },

+    ['u'] = { 1, 1, 3, 0 },

+    ['v'] = { 1, 1, 1, 3, 0 },

+    ['w'] = { 1, 3, 3, 0 },

+    ['x'] = { 3, 1, 1, 3, 0 },

+    ['y'] = { 3, 1, 3, 3, 0 },

+    ['z'] = { 3, 3, 1, 1, 0 }

+  };

+

+static void

+grub_audio_tone (int length)

+{

+  grub_speaker_beep_on (1000);

+  grub_millisleep (length);

+  grub_speaker_beep_off ();

+}

+

+static void

+grub_audio_putchar (struct grub_term_output *term __attribute__ ((unused)),

+		    const struct grub_unicode_glyph *c_in)

+{

+  grub_uint8_t c;

+  int i;

+

+  /* For now, do not try to use a surrogate pair.  */

+  if (c_in->base > 0x7f)

+    c = '?';

+  else

+    c = grub_tolower (c_in->base);

+  for (i = 0; codes[c][i]; i++)

+    {

+      grub_audio_tone (codes[c][i] * BASE_TIME);

+      grub_millisleep (BASE_TIME);

+    }

+  grub_millisleep (2 * BASE_TIME);

+}

+

+

+static int

+dummy (void)

+{

+  return 0;

+}

+

+static struct grub_term_output grub_audio_term_output =

+  {

+   .name = "morse",

+   .init = (void *) dummy,

+   .fini = (void *) dummy,

+   .putchar = grub_audio_putchar,

+   .getwh = (void *) dummy,

+   .getxy = (void *) dummy,

+   .gotoxy = (void *) dummy,

+   .cls = (void *) dummy,

+   .setcolorstate = (void *) dummy,

+   .setcursor = (void *) dummy,

+   .normal_color = GRUB_TERM_DEFAULT_NORMAL_COLOR,

+   .highlight_color = GRUB_TERM_DEFAULT_HIGHLIGHT_COLOR,

+   .flags = GRUB_TERM_CODE_TYPE_ASCII | GRUB_TERM_DUMB

+  };

+

+GRUB_MOD_INIT (morse)

+{

+  grub_term_register_output ("audio", &grub_audio_term_output);

+}

+

+GRUB_MOD_FINI (morse)

+{

+  grub_term_unregister_output (&grub_audio_term_output);

+}

diff --git a/grub-core/term/spkmodem.c b/grub-core/term/spkmodem.c

new file mode 100644

index 0000000..31dab65

--- /dev/null

+++ b/grub-core/term/spkmodem.c

@@ -0,0 +1,106 @@

+/*  console.c -- Open Firmware console for GRUB.  */

+/*

+ *  GRUB  --  GRand Unified Bootloader

+ *  Copyright (C) 2003,2004,2005,2007,2008,2009  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/term.h>

+#include <grub/types.h>

+#include <grub/misc.h>

+#include <grub/mm.h>

+#include <grub/time.h>

+#include <grub/terminfo.h>

+#include <grub/dl.h>

+#include <grub/speaker.h>

+

+GRUB_MOD_LICENSE ("GPLv3+");

+

+extern struct grub_terminfo_output_state grub_spkmodem_terminfo_output;

+

+static void

+put (struct grub_term_output *term __attribute__ ((unused)), const int c)

+{

+  int i;

+

+  for (i = 7; i >= 0; i--)

+    {

+      if ((c >> i) & 1)

+	grub_speaker_beep_on (2000);

+      else

+	grub_speaker_beep_on (4000);

+      grub_millisleep (10);

+      grub_speaker_beep_on (1000);

+      grub_millisleep (10);

+    }

+  grub_speaker_beep_on (50);

+}

+

+static grub_err_t

+grub_spkmodem_init_output (struct grub_term_output *term)

+{

+  grub_speaker_beep_on (50);

+  grub_millisleep (50);

+

+  grub_terminfo_output_init (term);

+

+  return 0;

+}

+

+static grub_err_t

+grub_spkmodem_fini_output (struct grub_term_output *term __attribute__ ((unused)))

+{

+  grub_speaker_beep_off ();

+  return 0;

+}

+

+

+

+

+struct grub_terminfo_output_state grub_spkmodem_terminfo_output =

+  {

+    .put = put,

+    .width = 80,

+    .height = 24

+  };

+

+static struct grub_term_output grub_spkmodem_term_output =

+  {

+    .name = "spkmodem",

+    .init = grub_spkmodem_init_output,

+    .fini = grub_spkmodem_fini_output,

+    .putchar = grub_terminfo_putchar,

+    .getxy = grub_terminfo_getxy,

+    .getwh = grub_terminfo_getwh,

+    .gotoxy = grub_terminfo_gotoxy,

+    .cls = grub_terminfo_cls,

+    .setcolorstate = grub_terminfo_setcolorstate,

+    .setcursor = grub_terminfo_setcursor,

+    .flags = GRUB_TERM_CODE_TYPE_ASCII,

+    .data = &grub_spkmodem_terminfo_output,

+    .normal_color = GRUB_TERM_DEFAULT_NORMAL_COLOR,

+    .highlight_color = GRUB_TERM_DEFAULT_HIGHLIGHT_COLOR,

+  };

+

+GRUB_MOD_INIT (spkmodem)

+{

+  grub_term_register_output ("spkmodem", &grub_spkmodem_term_output);

+}

+

+

+GRUB_MOD_FINI (spkmodem)

+{

+  grub_term_unregister_output (&grub_spkmodem_term_output);

+}

diff --git a/include/grub/i386/pit.h b/include/grub/i386/pit.h

index ff9b9a6..e1c92cd 100644

--- a/include/grub/i386/pit.h

+++ b/include/grub/i386/pit.h

@@ -22,6 +22,84 @@

 #include <grub/types.h>

 #include <grub/err.h>

+enum

+  {

+    /* The PIT channel value ports.  You can write to and read from them.

+       Do not mess with timer 0 or 1.  */

+    GRUB_PIT_COUNTER_0 = 0x40,

+    GRUB_PIT_COUNTER_1 = 0x41,

+    GRUB_PIT_COUNTER_2 = 0x42,

+    /* The PIT control port.  You can only write to it.  Do not mess with

+       timer 0 or 1.  */

+    GRUB_PIT_CTRL = 0x43,

+    /* The speaker port.  */

+    GRUB_PIT_SPEAKER_PORT = 0x61,

+  };

+

+

+/* The speaker port.  */

+enum

+  {

+    /* If 0, follow state of SPEAKER_DATA bit, otherwise enable output

+       from timer 2.  */

+    GRUB_PIT_SPK_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.  */

+    GRUB_PIT_SPK_DATA = 0x02,

+

+    GRUB_PIT_SPK_TMR2_LATCH = 0x20

+  };

+

+/* The PIT control port.  You can only write to it.  Do not mess with

+   timer 0 or 1.  */

+enum

+  {

+    GRUB_PIT_CTRL_SELECT_MASK = 0xc0,

+    GRUB_PIT_CTRL_SELECT_0 = 0x00,

+    GRUB_PIT_CTRL_SELECT_1 = 0x40,

+    GRUB_PIT_CTRL_SELECT_2 = 0x80,

+

+    /* Read and load control.  */

+    GRUB_PIT_CTRL_READLOAD_MASK= 0x30,

+    GRUB_PIT_CTRL_COUNTER_LATCH = 0x00,	/* Hold timer value until read.  */

+    GRUB_PIT_CTRL_READLOAD_LSB = 0x10,	/* Read/load the LSB.  */

+    GRUB_PIT_CTRL_READLOAD_MSB = 0x20,	/* Read/load the MSB.  */

+    GRUB_PIT_CTRL_READLOAD_WORD = 0x30,	/* Read/load the LSB then the MSB.  */

+

+    /* Mode control.  */

+    GRUB_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.  */

+    GRUB_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.  */

+    GRUB_PIT_CTRL_PROGR_ONE_SHOT = 0x02,

+

+    /* Rate generator.  Output is low for one period of the counter, and

+       high for the other.  */

+    GRUB_PIT_CTRL_RATE_GEN = 0x04,

+

+    /* Square wave generator.  Output is low for one half of the period,

+       and high for the other half.  */

+    GRUB_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.  */

+    GRUB_PIT_CTRL_SOFTSTROBE = 0x08,

+

+    /* Hardware triggered strobe.  Like software triggered strobe, but

+       only starts the counter when the gate pin is set to high.  */

+    GRUB_PIT_CTRL_HARDSTROBE = 0x0a,

+

+

+    /* Count mode.  */

+    GRUB_PIT_CTRL_COUNT_MASK = 0x01,

+    GRUB_PIT_CTRL_COUNT_BINARY = 0x00,	/* 16-bit binary counter.  */

+    GRUB_PIT_CTRL_COUNT_BCD = 0x01	/* 4-decade BCD counter.  */

+  };

+

 void EXPORT_FUNC(grub_pit_wait) (grub_uint16_t tics);

 #endif /* ! KERNEL_CPU_PIT_HEADER */

diff --git a/include/grub/speaker.h b/include/grub/speaker.h

new file mode 100644

index 0000000..a076fcf

--- /dev/null

+++ b/include/grub/speaker.h

@@ -0,0 +1,47 @@

+#ifndef GRUB_SPEAKER_HEADER

+#define GRUB_SPEAKER_HEADER 1

+

+#include <grub/cpu/io.h>

+#include <grub/i386/pit.h>

+

+/* The frequency of the PIT clock.  */

+#define GRUB_SPEAKER_PIT_FREQUENCY		0x1234dd

+

+static inline void

+grub_speaker_beep_off (void)

+{

+  unsigned char status;

+

+  status = grub_inb (GRUB_PIT_SPEAKER_PORT);

+  grub_outb (status & ~(GRUB_PIT_SPK_TMR2 | GRUB_PIT_SPK_DATA),

+	     GRUB_PIT_SPEAKER_PORT);

+}

+

+static inline void

+grub_speaker_beep_on (grub_uint16_t pitch)

+{

+  unsigned char status;

+  unsigned int counter;

+

+  if (pitch < 20)

+    pitch = 20;

+  else if (pitch > 20000)

+    pitch = 20000;

+

+  counter = GRUB_SPEAKER_PIT_FREQUENCY / pitch;

+

+  /* Program timer 2.  */

+  grub_outb (GRUB_PIT_CTRL_SELECT_2

+	     | GRUB_PIT_CTRL_READLOAD_WORD

+	     | GRUB_PIT_CTRL_SQUAREWAVE_GEN

+	     | GRUB_PIT_CTRL_COUNT_BINARY, GRUB_PIT_CTRL);

+  grub_outb (counter & 0xff, GRUB_PIT_COUNTER_2);		/* LSB */

+  grub_outb ((counter >> 8) & 0xff, GRUB_PIT_COUNTER_2);	/* MSB */

+

+  /* Start speaker.  */

+  status = grub_inb (GRUB_PIT_SPEAKER_PORT);

+  grub_outb (status | GRUB_PIT_SPK_TMR2 | GRUB_PIT_SPK_DATA,

+	     GRUB_PIT_SPEAKER_PORT);

+}

+

+#endif

diff --git a/util/spkmodem-recv.c b/util/spkmodem-recv.c

new file mode 100644

index 0000000..cbec3af

--- /dev/null

+++ b/util/spkmodem-recv.c

@@ -0,0 +1,98 @@

+#include <stdio.h>

+#include <stdlib.h>

+#include <string.h>

+

+/* Compilation:  gcc -o spkmodem-recv spkmodem-recv  */

+/* Usage: parecord --channels=1 --rate=48000 --format=s16le | ./spkmodem-recv */

+

+#define RATE 48000

+#define SAMPLES_PER_TRAME 480

+#define AMPLITUDE_THRESHOLD 100000

+#define FREQ_SEP_MIN 15

+#define FREQ_SEP_NOM 20

+#define FREQ_SEP_MAX 25

+

+#define FREQ_DATA_MIN 10