arch/arm/include/debug/8250.S

Source file repositories/reference/linux-study-clean/arch/arm/include/debug/8250.S

File Facts

System
Linux kernel
Corpus path
arch/arm/include/debug/8250.S
Extension
.S
Size
1068 bytes
Lines
56
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.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/serial_reg.h>

		.macro	addruart, rp, rv, tmp
		ldr	\rp, =CONFIG_DEBUG_UART_PHYS
		ldr	\rv, =CONFIG_DEBUG_UART_VIRT
		.endm

#ifdef CONFIG_DEBUG_UART_8250_WORD
		.macro	store, rd, rx:vararg
	 ARM_BE8(rev \rd, \rd)
		str	\rd, \rx
	 ARM_BE8(rev \rd, \rd)
		.endm

		.macro	load, rd, rx:vararg
		ldr	\rd, \rx
	ARM_BE8(rev \rd, \rd)
		.endm
#else
		.macro	store, rd, rx:vararg
		strb	\rd, \rx
		.endm

		.macro	load, rd, rx:vararg
		ldrb	\rd, \rx
		.endm
#endif

#define UART_SHIFT CONFIG_DEBUG_UART_8250_SHIFT

		.macro	senduart,rd,rx
		store	\rd, [\rx, #UART_TX << UART_SHIFT]
		.endm

		.macro	busyuart,rd,rx
1002:		load	\rd, [\rx, #UART_LSR << UART_SHIFT]
		and	\rd, \rd, #UART_LSR_TEMT | UART_LSR_THRE
		teq	\rd, #UART_LSR_TEMT | UART_LSR_THRE
		bne	1002b
		.endm

		.macro	waituarttxrdy,rd,rx
		.endm

		.macro	waituartcts,rd,rx
1001:		load	\rd, [\rx, #UART_MSR << UART_SHIFT]
		tst	\rd, #UART_MSR_CTS
		beq	1001b
		.endm

Annotation

Implementation Notes