Recently，I modified the u-boot programs to promote the speed of u-boot. However， I‘m not sure how to monitor the time of it. I used instructions like“dmesg” or “systemd-analyze time”. But they didn’t display the time of u-boot. That time is about kernel.
Do you have the serial console working?
If so, you could try using a utility like grabserial with timestamps to see the time elapse from cboot, U-Boot, kernel, etc. on the console and find your “speed” of U-Boot.
Thank you for responding. I have already installed gtkterm to print the boot log. However, I don’t know how to use grabserial to find the speed of u-boot.
If you boot with gtkterm you can log. The timestamps which U-Boot prints are actual time in U-Boot. There will be some unlogged time in earlier boot stages, but you could literally use a stopwatch and count the time before the first timestamp is printed. grabserial will show you the same log.
Thanks， I‘ll use stopwatch to get the speed of u-boot.