Intel I945P Appendix, Search for a valid VGA device & VGA BIOS, and put it into C0000

Models: I945P

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-Search for a valid VGA device & VGA BIOS, and put it into C000:0.

Appendix

18h

Detect CPU information including brand, SMI type (Cyrix or Intel) and

 

CPU level (586 or 686).

19-1Ah

Reserved

1Bh

Initial interrupts vector table. If no special specified, all H/W

 

interrupts are directed to SPURIOUS_INT_HDLR & S/W

 

interrupts to SPURIOUS_soft_HDLR.

1Ch

Reserved

1Dh

Initial EARLY_PM_INIT switch.

1Eh

Reserved

1Fh

Load keyboard matrix (notebook platform)

20h

Reserved

21h

HPM initialization (notebook platform)

22h

Reserved

23h

1.

Check validity of RTC value:

 

 

e.g. a value of 5Ah is an invalid value for RTC minute.

 

2.

Load CMOS settings into BIOS stack. If CMOS checksum fails, use

 

 

default value instead.

 

3.

Prepare BIOS resource map for PCI & PnP use. If ESCD is valid,

 

 

take into consideration of the ESCD’s legacy information.

 

4.

Onboard clock generator initialization. Disable respective clock

 

 

resource to empty PCI & DIMM slots.

 

5.

Early PCI initialization:

 

 

-Enumerate PCI bus number

 

 

-Assign memory & I/O resource

 

 

-Search for a valid VGA device & VGA BIOS, and put it into C000:0.

24-26h

Reserved

27h

Initialize INT 09 buffer

28h

Reserved

29h

1.

Program CPU internal MTRR (P6 & PII) for 0-640K memory

 

 

address.

 

2.

Initialize the APIC for Pentium class CPU.

 

3.

Program early chipset according to CMOS setup.

 

 

Example: onboard IDE controller.

 

4.

Measure CPU speed.

 

5.

Invoke video BIOS.

2A-2Ch

Reserved

2Dh

1.

Initialize multi-language

 

2.

Put information on screen display, including Award title, CPU type,

 

 

CPU speed ….

2E-32h

Reserved

33h

Reset keyboard except Winbond 977 series Super I/O chips.

34-3Bh

Reserved

3Ch

Test 8254

3Dh

Reserved

3Eh

Test 8259 interrupt mask bits for channel 1.

3Fh

Reserved

40h

Test 8259 interrupt mask bits for channel 2.

41h

Reserved

42h

Reserved

B-2

Page 68
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Intel I945P specifications Appendix, Search for a valid VGA device & VGA BIOS, and put it into C0000