CHAPTER 8 - BIOS Setup
SPI-8450-LLVA 115
POST
(hex) Description
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.
24h Reserved
25h Reserved
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.
2Ah Reserved
2Bh Reserved
2Ch Reserved
2Dh 1. Initialize multi-language
2. Put information on screen display, including Award title, CPU type, CPU speed ….
2Eh Reserved
2Fh Reserved
30h Reserved
31h Reserved
32h Reserved
33h Reset keyboard except Winbond 977 series Super I/O chips.
34h Reserved
35h Reserved