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Diffstat (limited to 'doc/README.log')
-rw-r--r-- | doc/README.log | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/doc/README.log b/doc/README.log index f653fe7..dc9e2de 100644 --- a/doc/README.log +++ b/doc/README.log @@ -51,6 +51,7 @@ The following main categories are defined: LOGC_BOARD - Related to board-specific code LOGC_CORE - Related to core driver-model support LOGC_DT - Related to device tree control + LOGC_EFI - Related to EFI implementation Enabling logging @@ -68,6 +69,19 @@ If CONFIG_LOG is not set, then no logging will be available. The above have SPL versions also, e.g. CONFIG_SPL_MAX_LOG_LEVEL. +Log commands +------------ + +The 'log' command provides access to several features: + + level - access the default log level + format - access the console log format + rec - output a log record + test - run tests + +Type 'help log' for details. + + Using DEBUG ----------- @@ -94,6 +108,20 @@ enabled or disabled independently: console - goes to stdout +Log format +---------- + +You can control the log format using the 'log format' command. The basic +format is: + + LEVEL.category,file.c:123-func() message + +In the above, file.c:123 is the filename where the log record was generated and +func() is the function name. By default ('log format default') only the +function name and message are displayed on the console. You can control which +fields are present, but not the field order. + + Filters ------- @@ -121,6 +149,14 @@ Also debug() and error() will generate log records - these use LOG_CATEGORY as the category, so you should #define this right at the top of the source file to ensure the category is correct. +You can also define CONFIG_LOG_ERROR_RETURN to enable the log_ret() macro. This +can be used whenever your function returns an error value: + + return log_ret(uclass_first_device(UCLASS_MMC, &dev)); + +This will write a log record when an error code is detected (a value < 0). This +can make it easier to trace errors that are generated deep in the call stack. + Code size --------- |