include/linux/mc6821.h

File Facts

System

Linux kernel

Corpus path

include/linux/mc6821.h

Extension

.h

Size

1209 bytes

Lines

53

Domain

Core OS

Bucket

Core Kernel Interface

Inferred role

Core OS: implementation source

Status

source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

• Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• No C-style include directives detected by the generator.

Detected Declarations

• struct pia

Annotated Snippet

struct pia {
	union {
		volatile u_char pra;
		volatile u_char ddra;
	} ua;
	u_char pad1[PIA_REG_PADWIDTH];
	volatile u_char cra;
	u_char pad2[PIA_REG_PADWIDTH];
	union {
		volatile u_char prb;
		volatile u_char ddrb;
	} ub;
	u_char pad3[PIA_REG_PADWIDTH];
	volatile u_char crb;
	u_char pad4[PIA_REG_PADWIDTH];
};

#define ppra ua.pra
#define pddra ua.ddra
#define pprb ub.prb
#define pddrb ub.ddrb

#define PIA_C1_ENABLE_IRQ (1<<0)
#define PIA_C1_LOW_TO_HIGH (1<<1)
#define PIA_DDR (1<<2)
#define PIA_IRQ2 (1<<6)
#define PIA_IRQ1 (1<<7)

#endif

Annotation

• Detected declarations: `struct pia`.
• Atlas domain: Core OS / Core Kernel Interface.
• 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.