Caution: This page may contain information that is specific to the legacy version of the driver framework (DFv1).
You can have a driver send log messages to the syslog through the use of the zxlogf(<log_level>,...)
macro, which is defined in lib/ddk/debug.h.
Depending on the type of log level, by default, log messages are sent to the following logs:
To control which log levels are sent to the syslog (other than SERIAL
), the kernel commandline driver.<driver_name>.log=<level>
can be used. For example, driver.sdhci.log=TRACE
additionally enables DEBUG
and TRACE
logs for the sdhci driver, as we are setting a minimum log level, and TRACE
is lower than DEBUG
.
A driver's logs are tagged with the process name, “driver”, and the driver name. This can be used to filter the output of the syslog whilst searching for particular logs.
Note: There is both producer and consumer filtering applied to logs. The above covers the producer-side, for more information on the consumer-side, and on how to view driver logs, see viewing logs.