CPUInfo

Overview

CPUInfo provides CPU presence detection and topology information during the PEI phase. It reads CMOS register 0x4A to determine whether the CPU socket is populated, displays POST progress on the VGA text framebuffer at 0xB8000, and executes CPUID leaf 0x0B to enumerate processor topology (cores, threads, packages).

Key Functions

• GetCpuPresenceStatus -- Reads CMOS 0x4A to detect CPU presence
• DisplayPostProgress -- Writes progress codes to VGA text memory
• GetCpuTopology -- Executes CPUID 0x0B to retrieve topology data
• CpuInfoEntryPoint -- Main entry: dispatches CPU detection and display

Dependencies

• CMOS RTC (ports 0x70/0x71)
• VGA text framebuffer (0xB8000)
• CPUID instruction
• PEI Services (PeiServices)

Platform

• Architecture: IA32 (x86, PE32)
• Subsystem: EFI Boot Service Driver (0x000B)
• Machine: 0x014C (i386)
• Entry Point: 0x320