BIOS
20h | Reserved |
21h | HPM initialization (notebook platform) |
22h | Reserved |
| Check validity of RTC value; 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 |
23h | 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 |
| Program CPU internal MTRR (P6 & PII) for |
29h | Initialize the APIC for Pentium class CPU; Program early chipset |
| according to CMOS setup; Measure CPU speed; Invoke video BIOS |
2Ah | Reserved |
2Bh | Reserved |
2Ch | Reserved |
2Dh | Initialize multilanguage; Put information on screen display, including |
Award title, CPU type, CPU speed, etc... | |
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 |
3Fh | Reserved |
40h | Test 9259 interrupt mask bits for channel 2 |
41h | Reserved |
42h | Reserved |
43h | Test 8259 functionality |
44h | Reserved |
45h | Reserved |
46h | Reserved |
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