Abit AN7, User Manual

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D-2 Appendix D
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)
55 Display number of processors (multi-processor platform)
57
Display PnP logo
Early ISA PnP initialization
-Assign CSN to every ISA PnP device
59 Initialize the combined Trend Anti-Virus code
5B (Optional Feature) Show message for entering AWDFLASH.EXE from FDD (optional)
5D
1. Initialize Init_Onboard_Super_IO
2. Initialize Init_Onbaord_AUDIO
60
Okay to enter Setup utility; i.e. not until this POST stage can users enter the CMOS setup
utility
63 Reset keyboard if Early_Reset_KB is not defined
65 Initialize PS/2 Mouse
67 Prepare memory size information for function call: INT 15h ax=E820h
69 Turn on L2 cache
AN7