2.2 Boot Time Measurement

To measure boot time, follow these steps:

  1. Download and install Grabserial.
  2. Install Python (sudo apt-get install python3.6).
  3. Execute Grabserial by entering the following cmd during Linux/HSS boots up.
    sudo grabserial -v -d "/dev/ttyUSB0" -b 115200 -w 8 -p N -s 1 -e 90 -t -m "Starting kernel.*"
    Opening serial port /dev/ttyUSB0

Where,

  • -d = serial device
  • -t = print timestamps
  • -m = match string before starting to log
  • -e = number of seconds to capture for (useful when redirecting to a file: ensure that the file is closed cleanly and all output is recorded)
  • -o [filename] = output to filename.

Grabserial utility use jiffies (the time between two successive clock ticks) and also adds time stamp to all serial console outputs, which is convenient to analyze the boot time. For more information, see Grabserial.