blob: bc9749531723a33bd64ceb2a095b782bc9f7b724 [file] [log] [blame]
/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*
* Delay/beep functions used in dev-mode kernel selection.
*/
#include "sysincludes.h"
#include "crc32.h"
#include "gbb_header.h"
#include "utility.h"
#include "vboot_api.h"
#include "vboot_audio.h"
#include "vboot_audio_private.h"
#include "vboot_common.h"
/* BIOS doesn't have /usr/include */
#ifndef UINT_MAX
#define UINT_MAX 4294967295U /* 0xffffffff */
#endif
/*
* Need one second of noise in the first 22 seconds.
* Total delay >= 30 seconds, <= 5 minutes.
*/
#define REQUIRED_NOISE_TIME 1000
#define REQUIRED_NOISE_WITHIN 22000
#define REQUIRED_TOTAL_DELAY 30000
#define MAX_CUSTOM_DELAY 300000
/* These are visible externally only to make testing easier */
VbDevMusicNote default_notes_[] = { {20000, 0}, /* 20 seconds */
{250, 400}, /* two beeps */
{250, 0},
{250, 400},
{9250, 0} }; /* total 30 seconds */
uint32_t default_count_ = sizeof(default_notes_) / sizeof(VbDevMusicNote);
VbDevMusicNote short_notes_[] = { {2000, 0} }; /* two seconds */
uint32_t short_count_ = sizeof(short_notes_) / sizeof(VbDevMusicNote);
/* No need to dynamically allocate this, is there? */
static VbAudioContext au;
/* Convert from msecs to VbExGetTimer() units. */
static uint64_t ticks_per_msec = 0; /* Initialized by VbAudioOpen() */
static uint64_t VbMsecToTicks(uint16_t msec) {
return ticks_per_msec * msec;
}
/**
* Find and return a valid set of note events.
*
* We'll use the user's struct if possible, but we will still enforce the
* 30-second timeout and require at least a second of audible noise within that
* period. We allocate storage for two reasons: the user's struct will be in
* flash, which is slow to read, and we may need one extra note at the end to
* pad out the user's notes to a full 30 seconds. The caller should free it
* when finished.
*/
static void VbGetDevMusicNotes(VbAudioContext *audio, int use_short)
{
VbDevMusicNote *notebuf = 0;
VbDevMusicNote *builtin = 0;
VbDevMusic *hdr = CUSTOM_MUSIC_NOTES;
uint32_t maxsize = CUSTOM_MUSIC_MAXSIZE; /* always <= flash size (8M) */
uint32_t maxnotes, mysum, mylen, i;
uint32_t this_msecs, on_msecs, total_msecs;
uint32_t count;
VBDEBUG(("VbGetDevMusicNotes: use_short is %d, hdr is %p, "
"maxsize is %d\n", use_short, hdr, maxsize));
if (use_short) {
builtin = short_notes_;
count = short_count_;
goto nope;
}
builtin = default_notes_;
count = default_count_;
/* If we can't beep in the background, don't allow customization. */
if (!audio->background_beep)
goto nope;
if (!hdr || maxsize < sizeof(VbDevMusic))
goto nope;
if (0 != memcmp(hdr->sig, "$SND", sizeof(hdr->sig))) {
VBDEBUG(("VbGetDevMusicNotes: bad sig\n"));
goto nope;
}
/*
* How many notes will fit in the flash region? One more than you'd
* think, because there's one note in the header itself.
*/
maxnotes = 1 + (maxsize - sizeof(VbDevMusic)) / sizeof(VbDevMusicNote);
if (hdr->count == 0 || hdr->count > maxnotes) {
VBDEBUG(("VbGetDevMusicNotes: count=%d maxnotes=%d\n",
hdr->count, maxnotes));
goto nope;
}
/*
* CUSTOM_MUSIC_MAXSIZE can't be larger than the size of the flash
* (around 8M or so) so this isn't really necessary, but let's be safe
* anyway.
*/
if ((sizeof(VbDevMusicNote) > UINT_MAX / hdr->count) ||
(sizeof(hdr->count) >
UINT_MAX - hdr->count * sizeof(VbDevMusicNote))) {
VBDEBUG(("VbGetDevMusicNotes: count=%d, just isn't right\n",
hdr->count));
goto nope;
}
/* Now we know this won't overflow */
mylen = (uint32_t)(sizeof(hdr->count) +
hdr->count * sizeof(VbDevMusicNote));
mysum = Crc32(&(hdr->count), mylen);
if (mysum != hdr->checksum) {
VBDEBUG(("VbGetDevMusicNotes: mysum=%08x, want=%08x\n",
mysum, hdr->checksum));
goto nope;
}
VBDEBUG(("VbGetDevMusicNotes: custom notes struct at %p\n", hdr));
/*
* Measure the audible sound up to the first 22 seconds, being careful
* to avoid rollover. The note time is 16 bits, and the note count is
* 32 bits. The product should fit in 64 bits.
*/
total_msecs = 0;
on_msecs = 0;
for (i=0; i < hdr->count; i++) {
this_msecs = hdr->notes[i].msec ;
if (this_msecs) {
total_msecs += this_msecs;
if (total_msecs <= REQUIRED_NOISE_WITHIN &&
hdr->notes[i].frequency >= 100 &&
hdr->notes[i].frequency <= 2000)
on_msecs += this_msecs;
}
}
/* We require at least one second of noise in the first 22 seconds */
VBDEBUG(("VbGetDevMusicNotes: with %d msecs of sound to begin\n",
on_msecs));
if (on_msecs < REQUIRED_NOISE_TIME)
goto nope;
/*
* We'll also require that the total time be less than 5 minutes. No
* real reason, it just gives us less to worry about.
*/
VBDEBUG(("VbGetDevMusicNotes: lasting %d msecs\n", total_msecs));
if (total_msecs > MAX_CUSTOM_DELAY) {
goto nope;
}
/* One more check, just to be paranoid. */
if (hdr->count > (UINT_MAX / sizeof(VbDevMusicNote) - 1)) {
VBDEBUG(("VbGetDevMusicNotes: they're all out to get me!\n"));
goto nope;
}
/* Looks good. Allocate the space (plus one) and copy it over. */
notebuf = VbExMalloc((hdr->count + 1) * sizeof(VbDevMusicNote));
memcpy(notebuf, hdr->notes, hdr->count * sizeof(VbDevMusicNote));
count = hdr->count;
/* We also require at least 30 seconds of delay. */
if (total_msecs < REQUIRED_TOTAL_DELAY) {
/*
* If the total time is less than 30 seconds, the needed
* difference will fit in 16 bits.
*/
this_msecs = (REQUIRED_TOTAL_DELAY - total_msecs) & 0xffff;
notebuf[hdr->count].msec = this_msecs;
notebuf[hdr->count].frequency = 0;
count++;
VBDEBUG(("VbGetDevMusicNotes: adding %d msecs of silence\n",
this_msecs));
}
/* Done */
audio->music_notes = notebuf;
audio->note_count = count;
audio->free_notes_when_done = 1;
return;
nope:
/* No custom notes, use the default. The count is already set. */
VBDEBUG(("VbGetDevMusicNotes: using %d default notes\n", count));
audio->music_notes = builtin;
audio->note_count = count;
audio->free_notes_when_done = 0;
}
/**
* Initialization function. Returns context for processing dev-mode delay.
*/
VbAudioContext *VbAudioOpen(VbCommonParams *cparams)
{
GoogleBinaryBlockHeader *gbb = cparams->gbb;
VbAudioContext *audio = &au;
int use_short = 0;
uint64_t a, b;
/* Note: may need to allocate things here in future */
/* Calibrate audio delay */
a = VbExGetTimer();
VbExSleepMs(10);
b = VbExGetTimer();
ticks_per_msec = (b - a) / 10ULL ;
VBDEBUG(("VbAudioOpen() - ticks_per_msec is %" PRIu64 "\n",
ticks_per_msec));
/* Initialize */
memset(audio, 0, sizeof(*audio));
audio->background_beep = 1;
audio->play_until = b; /* "zero" starts now */
/* See if we have full background sound capability or not. */
if (VBERROR_SUCCESS != VbExBeep(0,0)) {
VBDEBUG(("VbAudioOpen() - VbExBeep() is limited\n"));
audio->background_beep = 0;
}
/*
* Prepare to generate audio/delay event. Use a short developer screen
* delay if indicated by GBB flags.
*/
if (gbb->major_version == GBB_MAJOR_VER && gbb->minor_version >= 1
&& (gbb->flags & GBB_FLAG_DEV_SCREEN_SHORT_DELAY)) {
VBDEBUG(("VbAudioOpen() - using short dev screen delay\n"));
use_short = 1;
}
VbGetDevMusicNotes(audio, use_short);
VBDEBUG(("VbAudioOpen() - note count %d\n", audio->note_count));
return audio;
}
/**
* Caller should loop without extra delay until this returns false.
*/
int VbAudioLooping(VbAudioContext *audio)
{
uint64_t now;
uint16_t freq = audio->current_frequency;
uint16_t msec = 0;
int looping = 1;
now = VbExGetTimer();
while (audio->next_note < audio->note_count &&
now >= audio->play_until) {
freq = audio->music_notes[audio->next_note].frequency;
msec = audio->music_notes[audio->next_note].msec;
audio->play_until += VbMsecToTicks(msec);
audio->next_note++;
}
if (now >= audio->play_until) {
looping = 0;
freq = 0;
}
/* Do action here. */
if (audio->background_beep) {
if (audio->current_frequency != freq) {
VbExBeep(0, freq);
audio->current_frequency = freq;
}
} else if (freq && msec) {
VbExBeep(msec, freq);
now = VbExGetTimer();
}
audio->last_time = now;
return looping;
}
/**
* Caller should call this prior to booting.
*/
void VbAudioClose(VbAudioContext *audio)
{
VbExBeep(0,0);
if (audio->free_notes_when_done)
VbExFree(audio->music_notes);
}