In my research, there are 2 ways to do this

Method 1

Hack 10_linux script in /etc/grub.d/ and insert generation codes for text booting menuentry

Advantages:

Generates text booting menuentry for all installed kernel versions

Takes care of new or redundant menuentries when you install/purge kernels

Downsides:

Requires deep understanding of shell scripting

The script source file may vary from one grub version to another

Edits need to be redone if grub package updates overwrite the modified script

Method 2

Use designated script for adding custom grub menuentry in /etc/grub.d

Advantages:

Easiest and least complicated

No chance of being overwritten so you do it only once

Downsides:

Only if you want each of your installed kernel versions to have text booting menuentry: Lot of works and harder to maintain Leaving behind redundant menuentries when you purge old kernel versions



In this short step, I'm going with method #2 since it's the easiest to explain here and we'll be creating text booting menuentry only for the latest kernel image that you use.