cpu - 系统启动时哪个核心首先初始化？

Question

我想知道多核处理器的哪个核心在 cpu 启动时首先初始化？ (我的意思是在引导加载程序级别)是第一个核心？还是随机核心？

Answer 1

您想阅读本地 apic，您可以在“第 2a 卷”中阅读:
http://www.intel.com/content/www/us/en/processors/architectures-software-developer-manuals.html
每个处理器都有一个对应的本地 apic，在每个本地 apic 中都有一个 apic ID 寄存器，它在系统初始化时被分配一个唯一的值。
联机的初始内核称为引导处理器 (BSP)，实际上可以是芯片上的任何物理内核。更多信息在“第 3a 卷”中，他们讨论了引导处理器选择过程。
以下是 vol3a 的摘录:

8.4.1 BSP and AP Processors

The MP initialization protocol defines two classes of processors: the bootstrap processor (BSP) and the application processors (APs). Following a power-up or RESET of an MP system, system hardware dynamically selects one of the processors on the system bus as the BSP. The remaining processors are designated as APs.

As part of the BSP selection mechanism, the BSP flag is set in the IA32_APIC_BASE MSR (see Figure 10-5) of the BSP, indicating that it is the BSP. This flag is cleared for all other processors.

The BSP executes the BIOS’s boot-strap code to configure the APIC environment, sets up system-wide data structures, and starts and initializes the APs. When the BSP and APs are initialized, the BSP then begins executing the operating-system initialization code.