arch/x86/boot/cpuflags.c

File Facts

System

Linux kernel

Corpus path

arch/x86/boot/cpuflags.c

Extension

.c

Size

2422 bytes

Lines

111

Domain

Architecture Layer

Bucket

arch/x86

Inferred role

Architecture Layer: implementation source

Status

source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

• CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/types.h
• bitops.h
• asm/processor-flags.h
• asm/msr-index.h
• cpuflags.h

Detected Declarations

• function has_fpu
• function has_eflag
• function cpuid_count
• function get_cpuflags

Annotated Snippet

if (max_intel_level >= 0x00000007) {
			cpuid_count(0x00000007, 0, &ignored, &ignored,
					&cpu.flags[16], &ignored);
		}

		cpuid(0x80000000, &max_amd_level, &ignored, &ignored,
		      &ignored);

		if (max_amd_level >= 0x80000001 &&
		    max_amd_level <= 0x8000ffff) {
			cpuid(0x80000001, &ignored, &ignored, &cpu.flags[6],
			      &cpu.flags[1]);
		}
	}
}

Annotation

• Immediate include surface: `linux/types.h`, `bitops.h`, `asm/processor-flags.h`, `asm/msr-index.h`, `cpuflags.h`.
• Detected declarations: `function has_fpu`, `function has_eflag`, `function cpuid_count`, `function get_cpuflags`.
• Atlas domain: Architecture Layer / arch/x86.
• Implementation status: source implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.