Root [AT&T] How can i tell if my bootloader is locked?

[By_design]

I am considering flashing a custom ROM on my rooted galaxy S4. Looks pretty easy to do as long as my boot loader isn't locked. How can i tell? Also is there anyway to check if CWM or TWRP recovery is installed on my device?

 

[AndroidProf]

If you have never tweaked around with your phone, chances are that you don't have either TWRP or CWM installed on your device. Anyhow you can check the custom recovery by booting into it by restarting your phone while holding the power + vol. up key + home key at the same time when the phone is restarting. For convenience you can watch the vid below

How to Boot into Recovery Mode for Samsung Galaxy S4 - YouTube

If you have TWRP or CWM, the recovery will say so (apart from having a custom logo and a totally changed scenario from the menu you see in the video above).

As for the bootloader, when you're in the download mode (that's restart while holding the vol. down + power + home key) you can check in the bootloader section to see if your boot loader is unlocked or not.

 

[By_design]

My screen looked similar with the same kind of menu that was on the video for recovery mode, but no mention of either CWM or TWRP. I used Odin to Root it. I have ROM toolbox PRO, which has a whole list of of custom ROMs that I can flash. I just wish there was some good detailed instructions on how to actually use it.