Hi,
I am studying Juno board trusted firmware.
I'm not clear why is trusted firmware BL2 set to secure-EL1 instead of EL3.
Thanks for your attention!
Emmy
I think largely because running everything at EL3 isn't a good design philosophy. Generally the code is partitioned so that it runs at the lowest privilege level needed to perform its function.
Note that BL1 (now called AP_BL1), which does run at EL3, is typically executed from internal ROM which will have space constraints, so there's a good reason why the functionality of this boot stage is reduced to what is necessary,
Hope that helps
MarkN.
Hi MarkN,
I'm clear.
Thank you!