arch/sh/lib/strlen.S

File Facts

System

Linux kernel

Corpus path

arch/sh/lib/strlen.S

Extension

.S

Size

827 bytes

Lines

72

Domain

Architecture Layer

Bucket

arch/sh

Inferred role

Architecture Layer: arch/sh

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>
ENTRY(strlen)
	mov	r4,r0
	and	#3,r0
	tst	r0,r0
	bt/s	1f
	 mov	#0,r2

	add	#-1,r0
	shll2	r0
	shll	r0
	braf	r0
	 nop

	mov.b	@r4+,r1
	tst	r1,r1
	bt	8f
	add	#1,r2

	mov.b	@r4+,r1
	tst	r1,r1
	bt	8f
	add	#1,r2

	mov.b	@r4+,r1
	tst	r1,r1
	bt	8f
	add	#1,r2

1:
	mov	#0,r3
2:
	mov.l	@r4+,r1
	cmp/str	r3,r1
	bf/s	2b
	 add	#4,r2

	add	#-4,r2
#ifndef __LITTLE_ENDIAN__
	swap.b	r1,r1
	swap.w	r1,r1
	swap.b	r1,r1
#endif
	extu.b	r1,r0
	tst	r0,r0
	bt/s	8f
	 shlr8	r1
	add	#1,r2
	extu.b	r1,r0
	tst	r0,r0
	bt/s	8f
	 shlr8	r1
	add	#1,r2
	extu.b	r1,r0
	tst	r0,r0
	bt	8f
	add	#1,r2
8:
	rts
	 mov	r2,r0

Annotation

• Immediate include surface: `linux/linkage.h`.
• Atlas domain: Architecture Layer / arch/sh.
• 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.