arch/arm/boot/compressed/head-xscale.S
Source file repositories/reference/linux-study-clean/arch/arm/boot/compressed/head-xscale.S
File Facts
- System
- Linux kernel
- Corpus path
arch/arm/boot/compressed/head-xscale.S- Extension
.S- Size
- 916 bytes
- Lines
- 36
- 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
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
#include <linux/linkage.h>
.section ".start", "ax"
__XScale_start:
@ Preserve r8/r7 i.e. kernel entry values
@ Data cache might be active.
@ Be sure to flush kernel binary out of the cache,
@ whatever state it is, before it is turned off.
@ This is done by fetching through currently executed
@ memory to be sure we hit the same cache.
bic r2, pc, #0x1f
add r3, r2, #0x10000 @ 64 kb is quite enough...
1: ldr r0, [r2], #32
teq r2, r3
bne 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
mcr p15, 0, r0, c7, c7, 0 @ flush I & D caches
@ disabling MMU and caches
mrc p15, 0, r0, c1, c0, 0 @ read control reg
bic r0, r0, #0x05 @ clear DC, MMU
bic r0, r0, #0x1000 @ clear Icache
mcr p15, 0, r0, c1, c0, 0
Annotation
- Immediate include surface: `linux/linkage.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.