Let me start with a warning. Do this only if you really want to. Do it at your own risk. Do it, only if you really know what you are doing.
I leave the developer mode on most of the times. There is this warning when I switch on my Chromebook, and I am ok with it. But this week, I met couple fo people who were not comfortable with this and wanted to disable thing warning, or at least reduce the time. They wanted to enjoy the extras that the developer mode gives too.
johnlewis.ie has a tutorial on how to delay the developer mode alert to about 2 seconds.
The procedure is a follows:
- Open Chromebook and enable/disable write protect jumper
- Read existing BIOS using flashrom
- Write new BIOS file with correct flags using gbb_utility
- Write new BIOS file to BIOS using flashrom