Western Digital T13/2132-D - Manual (Page 41)

June 23, 2010 T13/2132-D Revision 3
Working Draft Enhanced Disk Drive - 4 (EDD-4) 29
8 INT 13h Function Definitions
8.1 Overview
These function definitions include conventional, extended, and CD/DVD functions. The functions are
differentiated by their function numbers and register usage. The extended functions use DS:SI as a pointer to a
command packet. The conventional functions use ES:BX as a pointer to their transfer buffer. Functions 0-3Fh
are conventional functions. Functions 40h through 49h are extended functions. Functions 4Ah through 4Dh are
CD/DVD boot functions. Functions 4Eh through 50h are hardware control functions.
The values in all registers that are not explicitly defined in the following sections shall be preserved at the
completion of each function call.
In the following clauses Entry specifies the contents that shall be in the x86 registers prior to making the
specified function call. Exit specifies the contents that shall be in the x86 registers when the function call is
complete. Carry clear indicates that CF=0b and carry set indicates that CF=1b.
Unlisted values in entry and exit condition may have result in indeterminate behavior.
Error codes which are not listed are outside the scope of this standard.