Logging API

enum log_level_t

Log levels supported, ranging from most to least important

Constants

LOGL_EMERG

U-Boot is unstable

LOGL_ALERT

Action must be taken immediately

LOGL_CRIT

Critical conditions

LOGL_ERR

Error that prevents something from working

LOGL_WARNING

Warning may prevent optimal operation

LOGL_NOTICE

Normal but significant condition, printf()

LOGL_INFO

General information message

LOGL_DEBUG

Basic debug-level message

LOGL_DEBUG_CONTENT

Debug message showing full message content

LOGL_DEBUG_IO

Debug message showing hardware I/O access

LOGL_COUNT

Total number of valid log levels

LOGL_NONE

Used to indicate that there is no valid log level

LOGL_LEVEL_MASK

Mask for valid log levels

LOGL_FORCE_DEBUG

Mask to force output due to LOG_DEBUG

LOGL_FIRST

The first, most-important log level

LOGL_MAX

The last, least-important log level

LOGL_CONT

Use same log level as in previous call

enum log_category_t

Log categories supported.

Constants

LOGC_FIRST

First log category

LOGC_NONE

Default log category

LOGC_ARCH

Related to arch-specific code

LOGC_BOARD

Related to board-specific code

LOGC_CORE

Related to core features (non-driver-model)

LOGC_DM

Core driver-model

LOGC_DT

Device-tree

LOGC_EFI

EFI implementation

LOGC_ALLOC

Memory allocation

LOGC_SANDBOX

Related to the sandbox board

LOGC_BLOBLIST

Bloblist

LOGC_DEVRES

Device resources (devres_... functions)

LOGC_ACPI

Advanced Configuration and Power Interface (ACPI)

LOGC_BOOT

Related to boot process / boot image processing

LOGC_COUNT

Number of log categories

LOGC_END

Sentinel value for lists of log categories

LOGC_CONT

Use same category as in previous call

Description

Log categories between LOGC_FIRST and LOGC_NONE correspond to uclasses (i.e. enum uclass_id), but there are also some more generic categories.

Remember to update log_cat_name[] after adding a new category.

int _log(enum log_category_t cat, enum log_level_t level, const char *file, int line, const char *func, const char *fmt, ...)

Internal function to emit a new log record

Parameters

enum log_category_t cat

Category of log record (indicating which subsystem generated it)

enum log_level_t level

Level of log record (indicating its severity)

const char *file

File name of file where log record was generated

int line

Line number in file where log record was generated

const char *func

Function where log record was generated

const char *fmt

printf() format string for log record

...

Optional parameters, according to the format string fmt

Return

0 if log record was emitted, -ve on error

assert(x)

assert expression is true

Parameters

x

expression to test

Description

If the expression x evaluates to false and _DEBUG evaluates to true, a panic message is written and the system stalls. The value of _DEBUG is set to true if DEBUG is defined before including common.h.

The expression x is always executed irrespective of the value of _DEBUG.

struct log_rec

a single log record

Definition

struct log_rec {
  enum log_category_t cat;
  enum log_level_t level;
  u16 line;
  u8 flags;
  const char *file;
  const char *func;
  const char *msg;
};

Members

cat

Category, representing a uclass or part of U-Boot

level

Severity level, less severe is higher

line

Line number where the log record was generated

flags

Flags for log record (enum log_rec_flags)

file

Name of file where the log record was generated (not allocated)

func

Function where the log record was generated (not allocated)

msg

Log message (allocated)

Description

Holds information about a single record in the log

Members marked as ‘not allocated’ are stored as pointers and the caller is responsible for making sure that the data pointed to is not overwritten. Members marked as ‘allocated’ are allocated (e.g. via strdup()) by the log system.

TODO(sjg**chromium.org**): Compress this struct down a bit to reduce space, e.g. a single u32 for cat, level, line and force_debug

struct log_driver

a driver which accepts and processes log records

Definition

struct log_driver {
  const char *name;
  int (*emit)(struct log_device *ldev, struct log_rec *rec);
  unsigned short flags;
};

Members

name

Name of driver

emit

emit a log record

Called by the log system to pass a log record to a particular driver for processing. The filter is checked before calling this function.

flags

Initial value for flags (use LOGDF_ENABLE to enable on start-up)

struct log_device

an instance of a log driver

Definition

struct log_device {
  unsigned short next_filter_num;
  unsigned short flags;
  struct log_driver *drv;
  struct list_head filter_head;
  struct list_head sibling_node;
};

Members

next_filter_num

Sequence number of next filter filter added (0=no filters yet). This increments with each new filter on the device, but never decrements

flags

Flags for this filter (enum log_device_flags)

drv

Pointer to driver for this device

filter_head

List of filters for this device

sibling_node

Next device in the list of all devices

Description

Since drivers are set up at build-time we need to have a separate device for the run-time aspects of drivers (currently just a list of filters to apply to records send to this device).

enum log_filter_flags

Flags which modify a filter

Constants

LOGFF_HAS_CAT

Filter has a category list

LOGFF_DENY

Filter denies matching messages

LOGFF_LEVEL_MIN

Filter’s level is a minimum, not a maximum

struct log_filter

criteria to filter out log messages

Definition

struct log_filter {
  int filter_num;
  int flags;
  enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
  enum log_level_t level;
  const char *file_list;
  struct list_head sibling_node;
};

Members

filter_num

Sequence number of this filter. This is returned when adding a new filter, and must be provided when removing a previously added filter.

flags

Flags for this filter (LOGFF_...)

cat_list

List of categories to allow (terminated by LOGC_END). If empty then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries can be provided

level

Maximum (or minimum, if LOGFF_MIN_LEVEL) log level to allow

file_list

List of files to allow, separated by comma. If NULL then all files are permitted

sibling_node

Next filter in the list of filters for this log device

Description

If a message matches all criteria, then it is allowed. If LOGFF_DENY is set, then it is denied instead.

const char * log_get_cat_name(enum log_category_t cat)

Get the name of a category

Parameters

enum log_category_t cat

Category to look up

Return

category name (which may be a uclass driver name) if found, or

“<invalid>” if invalid, or “<missing>” if not found. All error responses begin with ‘<’.

enum log_category_t log_get_cat_by_name(const char *name)

Look up a category by name

Parameters

const char *name

Name to look up

Return

Category, or LOGC_NONE if not found

const char * log_get_level_name(enum log_level_t level)

Get the name of a log level

Parameters

enum log_level_t level

Log level to look up

Return

Log level name (in ALL CAPS)

enum log_level_t log_get_level_by_name(const char *name)

Look up a log level by name

Parameters

const char *name

Name to look up

Return

Log level, or LOGL_NONE if not found

struct log_device * log_device_find_by_name(const char *drv_name)

Look up a log device by its driver’s name

Parameters

const char *drv_name

Name of the driver

Return

the log device, or NULL if not found

bool log_has_cat(enum log_category_t cat_list[], enum log_category_t cat)

check if a log category exists within a list

Parameters

enum log_category_t cat_list[]

List of categories to check, at most LOGF_MAX_CATEGORIES entries long, terminated by LC_END if fewer

enum log_category_t cat

Category to search for

Return

true if cat is in cat_list, else false

bool log_has_file(const char *file_list, const char *file)

check if a file is with a list

Parameters

const char *file_list

List of files to check, separated by comma

const char *file

File to check for. This string is matched against the end of each file in the list, i.e. ignoring any preceding path. The list is intended to consist of relative pathnames, e.g. common/main.c,cmd/log.c

Return

true if file is in file_list, else false

int log_add_filter_flags(const char *drv_name, enum log_category_t cat_list[], enum log_level_t level, const char *file_list, int flags)

Add a new filter to a log device, specifying flags

Parameters

const char *drv_name

Driver name to add the filter to (since each driver only has a single device)

enum log_category_t cat_list[]

List of categories to allow (terminated by LOGC_END). If empty then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries can be provided

enum log_level_t level

Maximum (or minimum, if LOGFF_LEVEL_MIN) log level to allow

const char *file_list

List of files to allow, separated by comma. If NULL then all files are permitted

int flags

Flags for this filter (LOGFF_...)

Return

the sequence number of the new filter (>=0) if the filter was added, or a -ve value on error

int log_add_filter(const char *drv_name, enum log_category_t cat_list[], enum log_level_t max_level, const char *file_list)

Add a new filter to a log device

Parameters

const char *drv_name

Driver name to add the filter to (since each driver only has a single device)

enum log_category_t cat_list[]

List of categories to allow (terminated by LOGC_END). If empty then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries can be provided

enum log_level_t max_level

Maximum log level to allow

const char *file_list

List of files to allow, separated by comma. If NULL then all files are permitted

Return

the sequence number of the new filter (>=0) if the filter was added, or a -ve value on error

int log_remove_filter(const char *drv_name, int filter_num)

Remove a filter from a log device

Parameters

const char *drv_name

Driver name to remove the filter from (since each driver only has a single device)

int filter_num

Filter number to remove (as returned by log_add_filter())

Return

0 if the filter was removed, -ENOENT if either the driver or the filter number was not found

int log_device_set_enable(struct log_driver *drv, bool enable)

Enable or disable a log device

Parameters

struct log_driver *drv

Driver of device to enable

bool enable

true to enable, false to disable return 0 if OK, -ENOENT if the driver was not found

Description

Devices are referenced by their driver, so use LOG_GET_DRIVER(name) to pass the driver to this function. For example if the driver is declared with LOG_DRIVER(wibble) then pass LOG_GET_DRIVER(wibble) here.

int log_init(void)

Set up the log system ready for use

Parameters

void

no arguments

Return

0 if OK, -ENOMEM if out of memory

int log_get_default_format(void)

get default log format

Parameters

void

no arguments

Description

The default log format is configurable via CONFIG_LOGF_FILE, CONFIG_LOGF_LINE, and CONFIG_LOGF_FUNC.

Return

default log format