Hi experts Ash Wilding Mark Nicholson,
I have a Juno r1 board and I'm using it as the instruction of this page's "Building from source" section.
Now I want to update some secure related registers (e.g., SCR_EL3) for my board. These update operations require EL3 privilege.
In this case, I think I need to write the code in secure monitor layer. I hope I can update the register value while booting time so I think I should add code in the BL2 or BL31 according to the Linaro slides page8.
My workspace contains the folder arm-tf which looks like the part I should work with.
However, after running script build-arm-tf.sh, I do get the bl2.bin and bl31.bin while I don't know how to push these files into my board and use them for trusted booting.
So my questions are:
1. To update the register with EL3 privilege, should I add code in trusted firmware layer?
2. Can I update the trusted firmware by myself for Juno r1? If I can, how?
If I misunderstand any part, please let me know.
Thank you in advance.
Shengye