/**
* In Dune2, the frequency of the VOC files are all over the place.
* Atari STE/TT/Falcon sound only supports a few fixed frequencies.
* So, we convert all audio to one frequency. That's also the occasion
* to convert from unsigned 8bits samples to SIGNED 8bits samples.
* Sadly, our knowledge of audio is not really good, so this is a linear
* scaler.
*/
static uint32 DSP_ConvertAudio(uint32 freq, const uint8 * src, uint32 len)
{
uint32 newlen = len * DMASOUND_FREQ / freq;
uint8 *w;
uint8 sample;
uint32 i, j;
Debug("converting freq from %uHz to %u.\n",
freq, DMASOUND_FREQ);
if(newlen > s_stRamBufferSize) {
if(Mshrink(s_stRamBuffer, newlen) == 0) {
s_stRamBufferSize = newlen;
} else {
Error("Mshrink() of ST RAM buffer failed. newlen=%u\n", newlen);
return 0;
}
}
w = s_stRamBuffer;
for (i = 1, j = 0; i <= len; i++) {
sample = (*src++) ^ 0x80; /* unsigned to signed conversion */
while (j < i * DMASOUND_FREQ / freq) {
*w++ = sample;
j++;
}
}
return newlen;
}
/* use long instead of int so vfork works OK with -mshort */
long
tfork(int (*func)(long), long arg)
{
register BASEPAGE *b;
register long pid;
register long savpending, savmask;
register BASEPAGE *savbase;
sighandler_t savhandler[NSIG];
long now;
int i;
b = (BASEPAGE *)Pexec(PE_CBASEPAGE, 0L, "", 0L);
(void)Mshrink(b, SIZE+256);
b->p_tbase = (char *)startup;
b->p_dbase = (char *)func;
b->p_dlen = arg;
b->p_hitpa = ((char *)b) + SIZE + 256;
pid = Pexec(104, 0L, b, 0L);
if (pid == -ENOSYS)
{
/* save the signal masks and signal handlers,
* the child may change them
*/
savpending = _sigpending;
_sigpending = 0;
savmask = _sigmask;
_sigmask = 0;
for (i = 0; i < NSIG; i++)
savhandler[i] = _sig_handler[i];
savbase = _base;
_base = b;
now = _clock();
pid = Pexec(4, 0L, b, 0L);
_base = savbase;
/* restore signal stuff */
for (i = 0; i < NSIG; i++)
_sig_handler[i] = savhandler[i];
_sigmask = savmask;
_sigpending = savpending;
if (pid >= 0) {
long retval = pid;
/* see the TOS algorithm for getpid() */
pid = ((long)b) >> 8;
__waitval = (pid << 16) | retval;
raise(SIGCHLD);
__waittime = _clock() - now;
_childtime += __waittime;
}
static void
start(BASEPAGE *bp)
{
long shrinklen;
_base = bp;
shrinklen = bp->p_tlen + bp->p_dlen + bp->p_blen + STACK + 0x100;
if (bp->p_lowtpa + shrinklen <= bp->p_hitpa) {
static char null[1] = {""};
static char *argv[2] = {null, NULL};
extern __builtin_putreg P_((int, long)); /* totally bogus */
__builtin_putreg(15, bp->p_lowtpa + shrinklen);
Mshrink((void *)bp->p_lowtpa, shrinklen);
main(1, argv);
}
Pterm(ENSMEM);
}
void _crtinit(void)
{
register BASEPAGE *bp;
register long m;
register long freemem;
bp = _base;
/* m = # bytes used by environment + args */
m = parseargs(bp);
/* make m the total number of bytes required by program sans stack/heap */
m += (bp->p_tlen + bp->p_dlen + bp->p_blen + sizeof(BASEPAGE));
m = (m + 3L) & (~3L);
/* freemem the amount of free mem accounting for MINFREE at top */
if ((freemem = (long)bp->p_hitpa - (long)bp - MINFREE - m) <= 0L)
goto notenough;
/* make m the total number of bytes including stack */
m += _stksize;
/* make sure there's enough room for the stack */
if (((long)bp + m) > ((long)bp->p_hitpa - MINFREE))
goto notenough;
/* set up the new stack to bp + m */
_setstack((char *)bp + m);
/* shrink the TPA */
(void)Mshrink(0, bp, m);
Pterm(main());
__builtin_unreachable();
notenough:
(void) Cconws("Fatal error: insufficient memory\r\n"
"Hint: either decrease stack size using 'stack' command (not recomended)\r\n"
" or increase TPA_INITIALMEM value in mint.cnf.\r\n");
Pterm(-1);
__builtin_unreachable();
}
