arch/arm/lib/muldi3.S

File Facts

System

Linux kernel

Corpus path

arch/arm/lib/muldi3.S

Extension

.S

Size

771 bytes

Lines

46

Domain

Architecture Layer

Bucket

arch/arm

Inferred role

Architecture Layer: arch/arm

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
• 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>

#ifdef __ARMEB__
#define xh r0
#define xl r1
#define yh r2
#define yl r3
#else
#define xl r0
#define xh r1
#define yl r2
#define yh r3
#endif

ENTRY(__muldi3)
ENTRY(__aeabi_lmul)

	mul	xh, yl, xh
	mla	xh, xl, yh, xh
	mov	ip, xl, lsr #16
	mov	yh, yl, lsr #16
	bic	xl, xl, ip, lsl #16
	bic	yl, yl, yh, lsl #16
	mla	xh, yh, ip, xh
	mul	yh, xl, yh
	mul	xl, yl, xl
	mul	ip, yl, ip
	adds	xl, xl, yh, lsl #16
	adc	xh, xh, yh, lsr #16
	adds	xl, xl, ip, lsl #16
	adc	xh, xh, ip, lsr #16
	ret	lr

ENDPROC(__muldi3)
ENDPROC(__aeabi_lmul)

Annotation

• Immediate include surface: `linux/linkage.h`, `asm/assembler.h`.
• Atlas domain: Architecture Layer / arch/arm.
• 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.