dmesg.c File Reference

In-memory ring buffer console. More...

#include <errno.h>
#include <ipxe/ansiesc.h>
#include <ipxe/settings.h>
#include <ipxe/console.h>

Go to the source code of this file.

Macros
#define	CONSOLE_DMESG   ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_TUI )
#define	DMESG_LEN   8192
	Size of ring buffer.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
	FILE_SECBOOT (PERMITTED)
static void	dmesg_putchar (int character)
	Print a character to the ring buffer.
static int	dmesg_fetch (void *data, size_t len)
	Fetch ring buffer setting.
static int	dmesg_store (const void *data __unused, size_t len)
	Store ring buffer setting.
const struct setting dmesg_setting	__setting (SETTING_MISC, dmesg)
	Ring buffer setting.

Variables
static char	dmesg [DMESG_LEN]
	Ring buffer.
static unsigned int	dmesg_offset
	Offset within ring buffer.
static struct ansiesc_handler	dmesg_ansiesc_handlers []
	Ring buffer ANSI escape sequence handlers.
static struct ansiesc_context	dmesg_ansiesc_ctx
	Ring buffer ANSI escape sequence context.
struct console_driver dmesg_console	__console_driver
	Ring buffer console driver.
struct builtin_setting dmesg_builtin_setting	__builtin_setting
	Ring buffer built-in setting.

Detailed Description

In-memory ring buffer console.

Definition in file dmesg.c.

Macro Definition Documentation

CONSOLE_DMESG

#define CONSOLE_DMESG   ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_TUI )

Definition at line 41 of file dmesg.c.

DMESG_LEN

#define DMESG_LEN   8192

Size of ring buffer.

Definition at line 45 of file dmesg.c.

Referenced by dmesg_fetch(), and dmesg_putchar().

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

FILE_SECBOOT()

FILE_SECBOOT

(

PERMITTED

)

dmesg_putchar()

void dmesg_putchar ( int character )

static

Print a character to the ring buffer.

Parameters

character

Character to be printed

Definition at line 68 of file dmesg.c.

                                            {
 
        /* Strip ANSI escape sequences */
        character = ansiesc_process ( &dmesg_ansiesc_ctx, character );
        if ( character < 0 )
                return;
 
        /* Handle backspace characters */
        if ( character == '\b' ) {
                if ( dmesg_offset )
                        dmesg_offset--;
                return;
        }
 
        /* Record character */
        dmesg[ dmesg_offset++ % DMESG_LEN ] = character;
}

References ansiesc_process(), dmesg, dmesg_ansiesc_ctx, DMESG_LEN, and dmesg_offset.

dmesg_fetch()

int dmesg_fetch ( void * data, size_t len )

static

Fetch ring buffer setting.

Parameters

data	Buffer to fill with setting data
len	Length of buffer

Return values

len	Length of setting data, or negative error

Definition at line 99 of file dmesg.c.

                                                  {
        uint8_t *bytes = data;
        size_t max;
        unsigned int offset;
 
        /* Calculate length */
        max = dmesg_offset;
        if ( max > DMESG_LEN )
                max = DMESG_LEN;
        if ( len > max )
                len = max;
 
        /* Copy data */
        offset = ( dmesg_offset - len );
        while ( len-- )
                *(bytes++) = dmesg[ offset++ % DMESG_LEN ];
 
        return max;
}

References bytes, data, dmesg, DMESG_LEN, dmesg_offset, len, max, and offset.

dmesg_store()

int dmesg_store ( const void *data __unused, size_t len )

static

Store ring buffer setting.

Parameters

data	Setting data, or NULL to clear setting
len	Length of setting data

Return values

rc	Return status code

Definition at line 126 of file dmesg.c.

                                                                 {
 
        /* Only clearing the log is supported */
        if ( len )
                return -ENOTSUP;
 
        /* Clear log */
        dmesg_offset = 0;
 
        return 0;
}

References __unused, data, dmesg_offset, ENOTSUP, and len.

__setting()

const struct setting dmesg_setting __setting	(	SETTING_MISC	,
		dmesg	)

Ring buffer setting.

References __setting, builtin_scope, dmesg, and SETTING_MISC.

Variable Documentation

dmesg

char dmesg[DMESG_LEN]

static

Ring buffer.

Definition at line 48 of file dmesg.c.

Referenced by __setting(), dmesg_fetch(), dmesg_putchar(), and PROVIDE_REQUIRING_SYMBOL().

dmesg_offset

unsigned int dmesg_offset

static

Offset within ring buffer.

Definition at line 51 of file dmesg.c.

Referenced by dmesg_fetch(), dmesg_putchar(), and dmesg_store().

dmesg_ansiesc_handlers

struct ansiesc_handler dmesg_ansiesc_handlers[]

static

Initial value:

                             = {
        { 0, NULL }
}

Ring buffer ANSI escape sequence handlers.

Definition at line 54 of file dmesg.c.

                                                       {
        { 0, NULL }
};

dmesg_ansiesc_ctx

struct ansiesc_context dmesg_ansiesc_ctx

static

Initial value:

                            = {
        .handlers = dmesg_ansiesc_handlers,
}

Ring buffer ANSI escape sequence context.

Definition at line 59 of file dmesg.c.

                                                {
        .handlers = dmesg_ansiesc_handlers,
};

Referenced by dmesg_putchar().

__console_driver

struct console_driver dmesg_console __console_driver

Initial value:

                    = {
        .putchar = dmesg_putchar,
        .usage = CONSOLE_DMESG,
}

Ring buffer console driver.

Definition at line 87 of file dmesg.c.

                                                     {
        .putchar = dmesg_putchar,
        .usage = CONSOLE_DMESG,
};

__builtin_setting

struct builtin_setting dmesg_builtin_setting __builtin_setting

Initial value:

                     = {
        .setting = &dmesg_setting,
        .fetch = dmesg_fetch,
        .store = dmesg_store,
}

Ring buffer built-in setting.

Definition at line 147 of file dmesg.c.

                                                               {
        .setting = &dmesg_setting,
        .fetch = dmesg_fetch,
        .store = dmesg_store,
};