| CD(4) | Kernel Interfaces Manual | CD(4) |
As the SCSI adapter is probed during boot, the SCSI bus is scanned for devices. Any devices found which answer as `Read-only' type devices will be `attached' to the cd driver.
For the use of flags with ATAPI devices, see wd(4).
The system utility disklabel(8) may be used to read the synthesized disk label structure, which will contain correct figures for the size of the CD-ROM should that information be required.
struct disklabel) Read or write the in-core copy of the disklabel for the drive. The disklabel is initialized with information read from the SCSI inquiry commands, and should be the same as the information printed at boot. This structure is defined in disklabel(5).struct ioc_play_track) Start audio playback given a track address and length. The structure is defined as follows:
struct ioc_play_track
{
u_char start_track;
u_char start_index;
u_char end_track;
u_char end_index;
};
struct ioc_play_blocks) Start audio playback given a block address and length. The structure is defined as follows:
struct ioc_play_blocks
{
int blk;
int len;
};
struct ioc_play_msf) Start audio playback given a `minutes-seconds-frames' address and length. The structure is defined as follows:
struct ioc_play_msf
{
u_char start_m;
u_char start_s;
u_char start_f;
u_char end_m;
u_char end_s;
u_char end_f;
};
struct ioc_read_subchannel) Read information from the subchannel at the location specified by this structure:
struct ioc_read_subchannel {
u_char address_format;
#define CD_LBA_FORMAT 1
#define CD_MSF_FORMAT 2
u_char data_format;
#define CD_SUBQ_DATA 0
#define CD_CURRENT_POSITION 1
#define CD_MEDIA_CATALOG 2
#define CD_TRACK_INFO 3
u_char track;
int data_len;
struct cd_sub_channel_info *data;
};
struct ioc_toc_header) Return summary information about the table of contents for the mounted CD-ROM. The information is returned into the following structure:
struct ioc_toc_header {
u_short len;
u_char starting_track;
u_char ending_track;
};
struct ioc_read_toc_entry) Return information from the table of contents entries mentioned. (Yes, this command name is misspelled). The argument structure is defined as follows:
struct ioc_read_toc_entry {
u_char address_format;
u_char starting_track;
u_short data_len;
struct cd_toc_entry *data;
};
The requested data is written into an area of size data_len and pointed to by data.struct ioc_patch) Attach various audio channels to various output channels. The argument structure is defined thusly:
struct ioc_patch {
u_char patch[4];
/* one for each channel */
};
struct ioc_vol) Get (set) information about the volume settings of the output channels. The argument structure is as follows:
struct ioc_vol
{
u_char vol[4];
/* one for each channel */
};
In addition the general scsi(4) ioctls may be used with the cd driver, if used against the `whole disk' partition (i.e. /dev/rcd0d for the bebox and i386 port, /dev/rcd0c for all other ports).
The audio code in the cd driver only support SCSI-2 standard audio commands. Because many CD-ROM manufacturers have not followed the standard, there are many CD-ROM drives for which audio will not work. Some work is planned to support some of the more common `broken' CD-ROM drives; however, this is not yet under way.
| January 16, 1996 | NetBSD 6.1 |