Detecting the Presence and Version of the Local APIC
The programmer can determine whether or not a processor supports the APIC architecture by executing a CPUID request type 1 and verifying that the EDX[APIC] bit = 1 (see Figure 61-7 on page 1509).
Figure 61-7. EDX After a CPUID Request Type 1
Assuming that the APIC is supported, the version of the APIC implementation may be determined by reading the Local APIC's Version Register. It has the format illustrated in Figure 61-8 on page 1510 and contains the following information:
The number of entries in the Local APIC's Local Vector Table (LVT). See “The Local Vector Table” on page 1539 for more ...
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