arch/x86/boot/copy.S

File Facts

System

Linux kernel

Corpus path

arch/x86/boot/copy.S

Extension

.S

Size

1041 bytes

Lines

66

Domain

Architecture Layer

Bucket

arch/x86

Inferred role

Architecture Layer: arch/x86

Status

atlas-only

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.

Dependency Surface

• linux/linkage.h

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

#include <linux/linkage.h>

/*
 * Memory copy routines
 */

	.code16
	.text

SYM_FUNC_START_NOALIGN(memcpy)
	pushw	%si
	pushw	%di
	movw	%ax, %di
	movw	%dx, %si
	pushw	%cx
	shrw	$2, %cx
	rep movsl
	popw	%cx
	andw	$3, %cx
	rep movsb
	popw	%di
	popw	%si
	retl
SYM_FUNC_END(memcpy)

SYM_FUNC_START_NOALIGN(memset)
	pushw	%di
	movw	%ax, %di
	movzbl	%dl, %eax
	imull	$0x01010101,%eax
	pushw	%cx
	shrw	$2, %cx
	rep stosl
	popw	%cx
	andw	$3, %cx
	rep stosb
	popw	%di
	retl
SYM_FUNC_END(memset)

SYM_FUNC_START_NOALIGN(copy_from_fs)
	pushw	%ds
	pushw	%fs
	popw	%ds
	calll	memcpy
	popw	%ds
	retl
SYM_FUNC_END(copy_from_fs)

SYM_FUNC_START_NOALIGN(copy_to_fs)
	pushw	%es
	pushw	%fs
	popw	%es
	calll	memcpy
	popw	%es
	retl
SYM_FUNC_END(copy_to_fs)

Annotation

• Immediate include surface: `linux/linkage.h`.
• Atlas domain: Architecture Layer / arch/x86.
• Implementation status: atlas-only.

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.