owtos.org/System/procstat.htm
                st += 'CPU cores: ';
                cpu = rate('cpu_0');
                st += 'User: ' + (cpu).toFixed(1);
                cpu = rate('cpu_2');
                st += ', Sys: ' + (cpu).toFixed(1);
                cpu = rate('cpu_3');
                st += ', Idle: ' + (cpu).toFixed(1);
                cpu = rate('cpu_4');
                st += ', Iowait: ' + (cpu).toFixed(1);
                cpu = rate('cpu_5');
                st += ', IRQ: ' + (cpu).toFixed(1