iPXE
Data Fields
int13_data Struct Reference

INT 13 SAN device private data. More...

Data Fields

unsigned int natural_drive
 BIOS natural drive number (0x00-0xff)
unsigned int cylinders
 Number of cylinders.
unsigned int heads
 Number of heads.
unsigned int sectors_per_track
 Number of sectors per track.
unsigned int boot_catalog
 Address of El Torito boot catalog (if any)
int last_status
 Status of last operation.

Detailed Description

INT 13 SAN device private data.

Definition at line 55 of file int13.c.


Field Documentation

BIOS natural drive number (0x00-0xff)

This is the drive number that would have been assigned by 'naturally' appending the drive to the end of the BIOS drive list.

If the emulated drive replaces a preexisting drive, this is the drive number that the preexisting drive gets remapped to.

Definition at line 66 of file int13.c.

Referenced by int13(), int13_hook(), and int13_sync_num_drives().

unsigned int int13_data::cylinders

Number of cylinders.

The cylinder number field in an INT 13 call is ten bits wide, giving a maximum of 1024 cylinders. Conventionally, when the 7.8GB limit of a CHS address is exceeded, it is the number of cylinders that is increased beyond the addressable limit.

Definition at line 76 of file int13.c.

Referenced by int13_get_extended_parameters(), int13_get_parameters(), int13_guess_geometry(), int13_hook(), and int13_rw_sectors().

unsigned int int13_data::heads

Number of heads.

The head number field in an INT 13 call is eight bits wide, giving a maximum of 256 heads. However, apparently all versions of MS-DOS up to and including Win95 fail with 256 heads, so the maximum encountered in practice is 255.

Definition at line 84 of file int13.c.

Referenced by int13_get_extended_parameters(), int13_get_parameters(), int13_guess_geometry(), int13_hook(), and int13_rw_sectors().

Number of sectors per track.

The sector number field in an INT 13 call is six bits wide, giving a maximum of 63 sectors, since sector numbering (unlike head and cylinder numbering) starts at 1, not 0.

Definition at line 91 of file int13.c.

Referenced by int13_get_extended_parameters(), int13_get_parameters(), int13_guess_geometry(), int13_hook(), and int13_rw_sectors().

Address of El Torito boot catalog (if any)

Definition at line 94 of file int13.c.

Referenced by int13_cdrom_read_boot_catalog(), and int13_parse_eltorito().

Status of last operation.

Definition at line 96 of file int13.c.

Referenced by int13(), and int13_get_last_status().


The documentation for this struct was generated from the following file: