Hi:
I read the following CDROM codes ,and have some difficulties to understand
them completely.
I am really new to the interface between hardware and software, and hope to
learn from all of
you.
From system call ioctl , I track to cdrom_ioctl, and have some problem to
understand it:
case CDROMPLAYMSF: {
2533 struct cdrom_msf msf;
2534 if (!CDROM_CAN(CDC_PLAY_AUDIO))
2535 return -ENOSYS;
2536 cdinfo(CD_DO_IOCTL, "entering CDROMPLAYMSF\n");
2537 IOCTL_IN(arg, struct cdrom_msf, msf);
2538 return cdo->audio_ioctl(cdi, cmd, &msf);
2539 }
My problem is:
1) Which routine is the real cdo->audio_ioctl?
2) Is this the lowest code to interact with hardware?
3) How does Linux play a CD? That is : cdo->audio_ioctl directly output
music data to CD-ROM's
audio out or write them to then input of soundcard?
Thanks a lot.
--cundong
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