6. Appendix
IPC-BX955 User’s manual
89
Table 6.3. POST Codes
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POST
(hex)
Description
1Dh
Initial EARLY_PM_INIT switch.
1Eh
Reserved
1Fh
Load keyboard matrix (notebook platform)
20h
Reserved
21h
HPM initialization (notebook platform)
22h
Reserved
23h
Check validity of RTC value: e.g. a value of 5Ah is an invalid value for RTC minute.
Load CMOS settings into BIOS stack. If CMOS checksum fails, use default value instead.
Prepare BIOS resource map for PCI & PnP use. If ESCD is valid, take into consideration of the ESCD’s
legacy information.
Onboard clock generator initialization. Disable respective clock resource to empty PCI & DIMM slots.
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
Program CPU internal MTRR (P6 & PII) for 0 - 640K memory address.
Initialize the APIC for Pentium class CPU.
Program early chipset according to CMOS setup. Example: onboard IDE controller.
Measure CPU speed.
Invoke video BIOS.
2Ah
Reserved
2Bh
Reserved
2Ch
Reserved
2Dh
Initialize multi-language
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
36h
Reserved
37h
Reserved
38h
Reserved
39h
Reserved
3Ah
Reserved
3Bh
Reserved
3Ch
Test 8254
3Dh
Reserved
3Eh
Test 8259 interrupt mask bits for channel 1.