Specifications

60 AMD Geode™ GeodeROM Functional Specification
Non-Removable Media
32087C
6.3.3.6 Function 48h - Extended Get Drive Parameters
Description:
Returns physical characteristics of the caller-specified drive.
Supports:
Fixed disks only.
Passed:
Returns:
Special Instructions:
DRIVE_INFO STRUCT 1
info_size dw 30 ; Size of the DRIVE_INFO structure
info_flags dw ; Information flag word (see Table 6-2)
cylinders dw ; Number of drive cylinders
heads dw ; Number of drive heads
sectors dw ; Number of drive sectors per track
sectors dq ; Total number of drive sectors
sector_size dw ; Number of bytes per sector on drive
DRIVE_INFO ENDS
The info_size field contains the size in bytes of the buffer passed in and returned, including this field. It must be set by
the caller before invoking this function, indicating the size of the buffer passed in. It is also filled in on return, indicating
the size of the buffer returned. The returned size cannot be larger than the passed-in size. This mechanism allows the
returned values of this function to be extended in the future with a minimum of compatibility problems. The info_flags
field is used to return additional information about the disk characteristics. Currently bits [6:0] are defined, and bits
[15:7] are reserved and must be set to zero by the implementor. Table 6-2 on page 61 gives the formats for bits [6:0] of
the flags field.
Related Functions:
None.
Parameter Description
AH 48h
DL Logical drive number (80h = drive 0, 81h = drive 1, etc.)
DS:SI Far pointer to caller’s buffer to receive drive information structure
Parameter Description
CF 0 = Success
1 = Failure
DS:SI Pointer to returned drive information structure, see Special (below).
AH Status code: See AH in "Function 01h - Get Disk Subsystem Status" on page 46.