arch/arm64/lib/strchr.S

File Facts

System

Linux kernel

Corpus path

arch/arm64/lib/strchr.S

Extension

.S

Size

643 bytes

Lines

35

Domain

Architecture Layer

Bucket

arch/arm64

Inferred role

Architecture Layer: exported/initcall integration point

Status

integration 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.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.

Dependency Surface

• linux/linkage.h
• asm/assembler.h

Detected Declarations

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

Annotated Snippet

#include <linux/linkage.h>
#include <asm/assembler.h>

/*
 * Find the first occurrence of a character in a string.
 *
 * Parameters:
 *	x0 - str
 *	x1 - c
 * Returns:
 *	x0 - address of first occurrence of 'c' or 0
 */
SYM_FUNC_START(__pi_strchr)
	and	w1, w1, #0xff
1:	ldrb	w2, [x0], #1
	cmp	w2, w1
	ccmp	w2, wzr, #4, ne
	b.ne	1b
	sub	x0, x0, #1
	cmp	w2, w1
	csel	x0, x0, xzr, eq
	ret
SYM_FUNC_END(__pi_strchr)

SYM_FUNC_ALIAS_WEAK(strchr, __pi_strchr)
EXPORT_SYMBOL_NOKASAN(strchr)

Annotation

• Immediate include surface: `linux/linkage.h`, `asm/assembler.h`.
• Atlas domain: Architecture Layer / arch/arm64.
• Implementation status: integration 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.