Filter
Top Products
Vol. 3 9-63
PROCESSOR MANAGEMENT AND INITIALIZATION
The READ_FAILURE error code returned by this function has meaning only if the
control function is implemented in the BIOS NVRAM. The state of this feature
(enabled/disabled) can also be implemented using CMOS RAM bits where READ
failure errors cannot occur.
9.11.8.8 Function 03H—Read Microcode Update Data
This function reads a currently installed microcode update from the BIOS storage into
a caller-provided RAM buffer. Table 9-17 lists the parameters and return codes.
Table 9-16. Mnemonic Values
Mnemonic Value Meaning
Enable 1 Enable the Update loading at initialization time.
Query 2 Determine the current state of the update control without
changing its status.
Table 9-17. Parameters for the Read Microcode Update Data Function
Input
AX Function Code 0D042H
BL Sub-function 03H - Read Update
ES:DI Buffer Address Real Mode pointer to the Intel Update
structure that will be written with the
binary data
ECX Scratch Pad1 Real Mode Segment address of 64
KBytes of RAM Block (lower 16 bits)
ECX Scratch Pad2 Real Mode Segment address of 64
KBytes of RAM Block (upper 16 bits)
DX Scratch Pad3 Real Mode Segment address of 64
KBytes of RAM Block
SS:SP Stack pointer 32 KBytes of Stack Minimum
SI Update Number This is the index number of the update
block to be read. This value is zero based
and must be less than the update count
returned from the presence test
function.
Output
CF Carry Flag Carry Set - Failure - AH contains Status
Carry Clear - All return
values are valid.
AH Return Code Status of the Call