Hi,
I just started to port our secure OS on an armv8 board, with a GIC-v3.
The EL1 non secure OS will be the vendor Linux OS, which runs in aarch64.
The EL1 secure OS will be our secure OS, which runs in aarch32.
At the moment, our OS only supports GIC-v2 implementation. Do I have to update our driver to handle the new GIC-v3 implementation or can I
use the legacy interface on the Secure side only so I don't have to change anything in our OS ?
Best,
V.
In §2.4 `Legacy support' of the GICv3 and GICv4 Software Overview (ARM DAI 0492B) you'll see that it's possible to have Secure EL1 remain in Legacy (GICv2) mode while EL3 and the Normal world (EL2 and Non-secure EL1) use Affinity Routing (GICv3), if that's what you're looking for.
This is done via a combination of GICD_CTLR.ARE_S, GICD_CTLR.ARE_NS, and ICC_SRE_EL[1,2,3].SRE.
Thank you, I wasn't sure if it was the case. It seems I will have to patch the low-level interrupt management now that IRQ are "current world interrupt" and FIQ are "other world interrupt" but that's okay.
Thank you !