arch/arm/include/debug/at91.S

File Facts

System

Linux kernel

Corpus path

arch/arm/include/debug/at91.S

Extension

.S

Size

1041 bytes

Lines

37

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

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

Detected Declarations

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

Annotated Snippet

#define AT91_DBGU_SR		(0x14)	/* Status Register */
#define AT91_DBGU_THR		(0x1c)	/* Transmitter Holding Register */
#define AT91_DBGU_TXRDY		(1 << 1)	/* Transmitter Ready */
#define AT91_DBGU_TXEMPTY	(1 << 9)	/* Transmitter Empty */

	.macro	addruart, rp, rv, tmp
	ldr	\rp, =CONFIG_DEBUG_UART_PHYS		@ System peripherals (phys address)
	ldr	\rv, =CONFIG_DEBUG_UART_VIRT		@ System peripherals (virt address)
	.endm

	.macro	senduart,rd,rx
	strb	\rd, [\rx, #(AT91_DBGU_THR)]		@ Write to Transmitter Holding Register
	.endm

	.macro	waituarttxrdy,rd,rx
1001:	ldr	\rd, [\rx, #(AT91_DBGU_SR)]		@ Read Status Register
	tst	\rd, #AT91_DBGU_TXRDY			@ DBGU_TXRDY = 1 when ready to transmit
	beq	1001b
	.endm

	.macro	waituartcts,rd,rx
	.endm

	.macro	busyuart,rd,rx
1001:	ldr	\rd, [\rx, #(AT91_DBGU_SR)]		@ Read Status Register
	tst	\rd, #AT91_DBGU_TXEMPTY			@ DBGU_TXEMPTY = 1 when transmission complete
	beq	1001b
	.endm

Annotation

• 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.