Nios® V Processor Software Developer Handbook

ID 743810
Date 10/31/2022
Public

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6.6.6.5. Custom Logging Messages

You can add custom messages that are sent to the Intel FPGA logging device. To define a custom message, include the header file alt_log_printf.h in your C source file as follows:

#include "sys/alt_log_printf.h"

Then use the following macro function:

ALT_LOG_PRINTF(const char *format, ...)

This C preprocessor macro invokes a pared-down version of printf(). The format argument supports most printf() options. It supports %c, %d, %I, %o, %s, %u, %x, and %X, as well as some precision and spacing modifiers, such as %-9.3o. It does not support floating point formats, such as %f or %g. This function is not compiled if Intel® FPGA logging is not enabled.

If you want your custom logging message to be controlled by Intel® FPGA logging preprocessor options, use the appropriate Intel® FPGA logging option preprocessor flags from the ALT_LOG_FLAGS Logging Levels table or the Intel FPGA Logging Options and Option Modifiers table.

Implementing Logging Options with Custom Logging Messages

/* The following example prints "Level 2 logging message" if
logging is set to level 2 or higher */
#if ( ALT_LOG_FLAGS >= 2 )
ALT_LOG_PRINTF ( "Level 2 logging message" );
#endif
/* The following example prints "Boot logging message" if boot logging
is turned on */
#if ( ALT_LOG_BOOT_ON_FLAG_SETTING == 1)
ALT_LOG_PRINTF ( "Boot logging message" );
#endif