Basic Input Output System (BIOS)
SAI2 Server Board TPS
Revision
1.0
36
; 5 Bytes must be used for each
JMP
Start
; JMP to maintain proper offset for
; each entry. Unused entry JMP’s
; should be filled with 5 byte
; filler or JMP to a RETF
JMP
ErrRet
;
JMP
ErrRet
JMP
ErrRet
JMP
ErrRet
3.5.2.2
Scan Point Definitions
The table below defines the bitmap for each scan point, indicating when the scan point occurs
and which resources are available (RAM, stack, binary data area, video, and keyboard).
Table 25. User Binary Area Scan Point Definitions
Scan Point
Mask
RAM/Stack/ Binary
Data Area (BDA)
Video/Keyboard
Near pointer to the user binary extension structure, mask bit is 0
if this structure is not present. Instead of a jump instruction the
scan address (offset 5) contains an 0CB followed by a near
pointer.
01h
Not applicable
Not applicable
Obsolete. No action taken.
02h
NA
NA
This scan occurs immediately after video initialization.
04h
Yes
Yes
This scan occurs immediately before video initialization.
08h
Yes
No
This scan occurs on POST error. On entry, BX contains the
number of the POST error.
10h Yes
Yes
This final scan occurs immediately prior to the INT 19 for normal
boot and allows one to completely circumvent the normal INT 19
boot if desired.
20h Yes
Yes
This scan occurs immediately before the normal option ROM
scan.
40h Yes
Yes
This scan occurs immediately following the option ROM area
scan.
80h Yes
Yes
Table 26. Format of the User Binary Information Structure
Offset
Bit Definition
0
Bit 0 = 1 if mandatory user binary, 0 if not mandatory. If a user binary is mandatory, it will always be
executed. If a platform supports a disabling of the user binary scan through Setup, this bit will override
Setup setting.
Bit 1 - 1 if runtime presence required (other than SMM user binary portion, SMM user binary will always be
present in runtime irrespective of setting of this bit).
0, if not required in runtime, and can be discarded at boot time.
Bit 7:2 – reserved for future expansion.
1 - 0fh
Reserved for future expansion.
