arch/um/drivers/ubd.h

File Facts

System

Linux kernel

Corpus path

arch/um/drivers/ubd.h

Extension

.h

Size

463 bytes

Lines

23

Domain

Architecture Layer

Bucket

arch/um

Inferred role

Architecture Layer: implementation source

Status

source 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.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• os.h

Detected Declarations

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

Annotated Snippet

#ifndef __UM_UBD_USER_H
#define __UM_UBD_USER_H

#include <os.h>

int start_io_thread(struct os_helper_thread **td_out, int *fd_out);
void *io_thread(void *arg);
extern int kernel_fd;

extern int ubd_read_poll(int timeout);
extern int ubd_write_poll(int timeout);

#define UBD_REQ_BUFFER_SIZE 64

#endif

Annotation

• Immediate include surface: `os.h`.
• Atlas domain: Architecture Layer / arch/um.
• Implementation status: source 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.