kmsg.c File Reference

/dev/kmsg (character device 1, 11): the kernel's messages. More...

#include <core/system.h>
#include <dev/dev.h>
#include <fs/posix.h>
#include <ds/ringbuf.h>
#include <sys/sched.h>
#include <console/earlycon.h>
#include <memdev.h>

Go to the source code of this file.

Functions
static ssize_t	kmsgdev_read (struct devid *dd, off_t offset, struct iobuf *io)
	Reads the kernel's messages from offset on, a piece at a time through a small buffer.
static ssize_t	kmsgdev_write (struct devid *dd, off_t offset, struct iobuf *io)
	Prints what is written as a kernel message.
static int	kmsg_file_open (struct file *file)
	Opens /dev/kmsg: its readers wait on the kernel's message queue.

Variables
struct dev	kmsgdev
struct ringbuf *	kmsg
struct waitq *	kmsg_wait

Detailed Description

/dev/kmsg (character device 1, 11): the kernel's messages.

Reading it gives what printk() printed, from the kernel's message ring (kmsg), at the offset the reader is at. Writing to it prints what is written as a kernel message.

Definition in file kmsg.c.

Function Documentation

kmsg_file_open()

int kmsg_file_open ( struct file * file )

static

Opens /dev/kmsg: its readers wait on the kernel's message queue.

Definition at line 75 of file kmsg.c.

References kmsg_file_open(), kmsg_wait, and posix_file_open().

Referenced by kmsg_file_open().

kmsgdev_read()

ssize_t kmsgdev_read ( struct devid * dd, off_t offset, struct iobuf * io )

static

Reads the kernel's messages from offset on, a piece at a time through a small buffer.

Definition at line 24 of file kmsg.c.

References iobuf_out(), kmsg, kmsgdev_read(), MIN, and iobuf::resid.

Referenced by kmsgdev_read().

kmsgdev_write()

ssize_t kmsgdev_write ( struct devid * dd, off_t offset, struct iobuf * io )

static

Prints what is written as a kernel message.

Definition at line 50 of file kmsg.c.

References iobuf::fault, iobuf_in(), kmsgdev_write(), MIN, printk(), and iobuf::resid.

Referenced by kmsgdev_write().

Variable Documentation

kmsg

struct ringbuf* kmsg

extern

Definition at line 25 of file printk.c.

Referenced by kmsgdev_read(), putc(), puts(), and vt_kmsg_replay().

kmsg_wait

struct waitq* kmsg_wait

extern

Definition at line 26 of file printk.c.

Referenced by kmsg_file_open().

kmsgdev

struct dev kmsgdev

Initial value:

         = {
    .read  = kmsgdev_read,
    .write = kmsgdev_write,
 
    .fops  = {
        .open  = kmsg_file_open,
        .read  = posix_file_read,
        .write = posix_file_write,
        .close = posix_file_close,
 
        .can_read  = __vfs_can_always,
        .can_write = __vfs_can_always,
        .eof       = __vfs_eof_never,
    },
}

Definition at line 18 of file kmsg.c.

Referenced by memdev_mux().