arch/sh/kernel/cpu/sh2a/ex.S

File Facts

System

Linux kernel

Corpus path

arch/sh/kernel/cpu/sh2a/ex.S

Extension

.S

Size

1020 bytes

Lines

71

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>

!
! convert Exception Vector to Exception Number
!

! exception no 0 to 255
exception_entry0:
no	=	0
	.rept	256
	mov.l	r1,@-sp
	bra	exception_trampoline0
	mov	#no,r1
no	=	no + 1
	.endr
exception_trampoline0:
	mov.l	r0,@-sp
	mov.l	1f,r0
	extu.b	r1,r1
	jmp	@r0
	  extu.w	r1,r1
	 
	.align	2
1:	.long	exception_handler

! exception no 256 to 511
exception_entry1:
no	=	0
	.rept	256
	mov.l	r1,@-sp
	bra	exception_trampoline1
	mov	#no,r1
no	=	no + 1
	.endr
exception_trampoline1:
	mov.l	r0,@-sp
	extu.b	r1,r1
	movi20	#0x100,r0
	add	r0,r1
	mov.l	1f,r0
	jmp	@r0
	  extu.w	r1,r1
	
	.align	2
1:	.long	exception_handler

	!
! Exception Vector Base
!
	.align	2
ENTRY(vbr_base)
vector	=	0
	.rept	256
	.long	exception_entry0 + vector * 6
vector	=	vector + 1
	.endr
vector	=	0
	.rept	256
	.long	exception_entry1 + vector * 6
vector	=	vector + 1
	.endr

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.