MS-9802 Mainboard
6-6
 10h   Auto detect flash type to load appropriate flash R/W codes into the 
 run time area in F000 for ESCD & DMI support. 
 11h   Reserved 
 12h   Use walking 1’s algorithm to check out interface in CMOS 
 circuitry.  Also set real-time clock power status, and then check for 
 override. 
 13h   Reserved 
 14h   Program chipset default values into chipset.  Chipset default 
 values are MODBINable by OEM customers. 
 15h   Reserved 
 16h   Initial Early_Init_Onboard_Generator switch. 
 17h   Reserved 
 18h   Detect CPU information including brand, SMI type (Cyrix or 
 Intel) and CPU level (586 or 686). 
 19h   Reserved 
 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. 
 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.