Debug Console

Printing on the Debug Console

The debug console is enabled by default and the corresponding laze module is debug-console. The ariel_os::debug::print!()/ariel_os::debug::println!() macros are used to print on the debug console.

When the debug console is enabled, panic messages are automatically printed to it. If this is unwanted, the panic-printing laze module can be disabled.

Debug Logging

Ariel OS supports debug logging on all platforms and it is enabled by default with the debug-logging-facade laze module. Debug logging offers a set of macros that print on the debug console with helpful logging formatting.

Logging

Within Rust code, import ariel_os::debug::log items, then use Ariel OS logging macros:

use ariel_os::debug::log::info;

#[ariel_os::task(autostart)]
async fn main() {
    info!("Hello!");
}

Filtering Logs

In Ariel OS, the log level defaults to info. It can be configured using the laze variable LOG. Depending on the logger, it may be possible to configure different levels per crate or per module.

Example:

$ laze build -C examples/log --builders nrf52840dk -DLOG=info run

Logging Facades and Loggers

Ariel OS supports multiple logging facades and loggers. Only one of them may be enabled at a time; if none of them are enabled, logging statements become no-operations. Enabling either the defmt or log laze modules allows selecting which logging facade and logger is used. defmt should be preferred when possible as it results in smaller binaries.

defmt

See the defmt documentation for general info on the defmt's facade and logger.

The defmt logger supports configuring the log level per crate and per module, as follows:

$ laze build -C examples/log --builders nrf52840dk -DLOG=info,ariel_os_rt=trace run

Note: On Cortex-M devices, the order of ariel_os::debug::println!() output and defmt log output is not deterministic.

log

Ariel OS's logger for log supports configuring the log level globally, but does not currently support per-crate filtering.