根据Intel的文档,FEE0 0000H
toFEE0 03F0H
是本地APIC的范围。然而,从 QEMU 控制台检查它,我只能找到值 0:
(qemu) x/128b 0xfee00000
fee00000: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00008: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00010: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00018: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00020: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00028: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00030: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00038: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00040: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00048: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00050: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00058: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00060: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00068: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00070: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
fee00078: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
我检查了 128 个字节,看看是否有任何不同于 0 的内容。至少,FEE0 0030H
应该包含一个不同的值,因为它是 APIC 版本所在的位置。
分页被禁用,因此没有虚拟内存;只是身体上的:
(qemu) info mem
PG disabled
但是,info lapic
命令报告实际的初始值:
(qemu) info lapic
dumping local APIC state for CPU 0
LVT0 0x00008700 active-hi level ExtINT (vec 0)
LVT1 0x00008400 active-hi level NMI
LVTPC 0x00010000 active-hi edge masked Fixed (vec 0)
LVTERR 0x00010000 active-hi edge masked Fixed (vec 0)
LVTTHMR 0x00010000 active-hi edge masked Fixed (vec 0)
LVTT 0x00030010 active-hi edge masked periodic Fixed (vec 16)
Timer DCR=0x2 (divide by 8) initial_count = 4096
SPIV 0x000001ff APIC enabled, focus=off, spurious vec 255
ICR 0x000c4610 physical edge assert all
ICR2 0x00000000
ESR 0x00000000
ISR (none)
IRR (none)
那么,这些值在哪里呢?