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_EVENT: Related to event and event handling
LOGC_FS: Related to filesystems
LOGC_EXPO: Related to expo handling
LOGC_CONSOLE: Related to the console and stdio
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, NULL if not known
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

int _log_buffer(enum log_category_t cat, enum log_level_t level, const char *file, int line, const char *func, ulong addr, const void *data, uint width, uint count, uint linelen): Internal function to print data buffer in hex and ascii form

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, NULL if not known
ulong addr: Starting address to display at start of line
const void *data: pointer to data buffer
uint width: data value width. May be 1, 2, or 4.
uint count: number of values to display
uint linelen: Number of values to print per line; specify 0 for default length

assert

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

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.

Return

0 if OK, -ENOENT if the driver was not found

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

void log_fixup_for_gd_move(struct global_data *new_gd): Handle global_data moving to a new place

Parameters

struct global_data *new_gd: Pointer to the new global data

Description

The log_head list is part of global_data. Due to the way lists work, moving the list will cause it to become invalid. This function fixes that up so that the log_head list will work correctly.