/* uptime.1.c -- tells how long the system has been running ** Copyright (c) 2020 Renaud Fivet ** ** v1 displays the number of seconds elapsed since boot */ #include extern volatile unsigned uptime ; extern void kputc( unsigned char c) ; void kputu( unsigned u) { unsigned r = u % 10 ; u /= 10 ; if( u) kputu( u) ; kputc( '0' + r) ; } int main( void) { static unsigned last ; for( ;;) if( last != uptime) { last = uptime ; kputu( last) ; puts( " sec") ; } else __asm( "WFI") ; /* Wait for System Tick Interrupt */ } /* end of uptime.1.c */