TYAN S6623, Manual

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POST (hex) Description
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.
1Dh
Initial EARLY_PM_INIT switch.
1Fh: Load keyboard matrix (notebook platform)
21h: HPM initialization (notebook platform)
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.
24h: Prepare BIOS resource map for PCI & PnP use. If ESCD
is valid, take into consideration of the ESCD’s legacy
information.
25h: 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
26h: 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
27h:
Initialize INT 09 buffer
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.
2Bh: Invoke Video BIOS
2Dh:
1. Initialize double-byte language font (Optional)
2. Put information on screen display, including Award title,
CPU type, CPU speed, full screen logo.
33h:
Reset keyboard if Early_Reset_KB is defined e.g. Winbond
977 series Super I/O chips. See also POST 63h.
35h:
Test DMA Channel 0.
37h:
Test DMA Channel 1.
39h: Test DMA page registers.
3Ch:
Test 8254
3Eh: Test 8259 interrupt mask bits for channel 1.
40h: Test 8259 interrupt mask bits for channel 2.
43h:
Test 8259 functionality.