Abit Intel Pentium 4 System Board Socket 775 AW8 User Manual
Page 68
H-2
Appendix H
1F
Load keyboard matrix (notebook platform)
21
HPM initialization (notebook platform)
23
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.
24
Prepare BIOS resource map for PCI & PnP use. If ESCD is valid, take into consideration
of the ESCD’s legacy information.
25
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
26
1. If Early_Init_Onboard_Generator is not defined Onboard clock generator initialization.
Disable respective clock resource to empty PCI & DIMM slots.
2. Init onboard PWM
3. Init onboard H/W monitor devices
27
Initialize INT 09 buffer
29
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.
2B
Invoke Video BIOS
2D
1. Initialize double-byte language font (Optional)
2. Put information on screen display, including Award title, CPU type, CPU speed, full
screen logo.
33
Reset keyboard if Early_Reset_KB is defined e.g. Winbond 977 series Super I/O chips.
See also POST 63.
35
Test DMA Channel 0
37
Test DMA Channel 1.
39
Test DMA page registers.
3C
Test 8254
3E
Test 8259 interrupt mask bits for channel 1
40
Test 8259 interrupt mask bits for channel 2
43
Test 8259 functionality
47
Initialize EISA slot
49
1. Calculate total memory by testing the last double word of each 64K page
2. Program writes allocation for AMD K5 CPU
4E
1. Program MTRR of M1 CPU
2. Initialize L2 cache for P6 class CPU & program CPU with proper cacheable range
3. Initialize the APIC for P6 class CPU
4. On MP platform, adjust the cacheable range to smaller one in case the cacheable ranges
between each CPU are not identical
50
Initialize USB
52
Test all memory (clear all extended memory to 0)
53
Clear password according to H/W jumper (Optional)
AW8 Series