arch/arm/include/debug/imx.S

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

File Facts

System
Linux kernel
Corpus path
arch/arm/include/debug/imx.S
Extension
.S
Size
1206 bytes
Lines
50
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 <asm/assembler.h>
#include "imx-uart.h"

/*
 * FIXME: This is a copy of IMX_IO_P2V in hardware.h, and needs to
 * stay sync with that.  It's hard to maintain, and should be fixed
 * globally for multi-platform build to use a fixed virtual address
 * for low-level debug uart port across platforms.
 */
#define IMX_IO_P2V(x)	(						\
			(((x) & 0x80000000) >> 7) |			\
			(0xf4000000 +					\
			(((x) & 0x50000000) >> 6) +			\
			(((x) & 0x0b000000) >> 4) +			\
			(((x) & 0x000fffff))))

#define UART_VADDR	IMX_IO_P2V(UART_PADDR)

		.macro	addruart, rp, rv, tmp
		ldr	\rp, =UART_PADDR	@ physical
		ldr	\rv, =UART_VADDR	@ virtual
		.endm

		.macro	senduart,rd,rx
		ARM_BE8(rev \rd, \rd)
		str	\rd, [\rx, #0x40]	@ TXDATA
		.endm

		.macro	waituartcts,rd,rx
		.endm

		.macro	waituarttxrdy,rd,rx
		.endm

		.macro	busyuart,rd,rx
1002:		ldr	\rd, [\rx, #0x98]	@ SR2
		ARM_BE8(rev \rd, \rd)
		tst	\rd, #1 << 3		@ TXDC
		beq	1002b			@ wait until transmit done
		.endm

Annotation

Implementation Notes