On Tue, May 10, 2016 at 1:09 AM, Peter Maydell <peter.mayd...@linaro.org> wrote: > On 10 May 2016 at 01:16, Alistair Francis <alistair.fran...@xilinx.com> wrote: >> It is actually a u-boot problem. I originally just assumed it was a >> Linux problem, but it happens before u-boot hands off to Linux. > > OK, that makes sense. u-boot tends to be a bit lower level and less > hardware-agnostic. I just wanted to check it wasn't caused by some > problem in QEMU's EL3 support we could easily fix. > >> It appears that u-boot won't work at all with EL3 enabled but EL2 >> disabled. It always moves to EL2 before moving to EL1 and there is no >> code prepared to handle going from EL3 directly to EL1. >> >> Just for the record, I'm specifically talking about what happens in >> the do_nonsec_virt_switch() function. >> >> It looks like there are three options: >> 1. Add support to u-boot to drop from EL3 to EL1 (I'm assuming this >> is possible, as not all implementations have EL2) >> 2. Just wait until QEMU adds EL2 support >> 3. Allow a QEMU command line option to start in EL1 instead of EL3 > > I would be OK with any of these three from a QEMU perspective. > Fixing u-boot is probably conceptually the nicest but I've never > looked at u-boot internals so it could be simple or painful...
I had a quick look and it didn't look easy to do unfortunately. Thanks, Alistair > > Edgar, do you have the list of what we're still missing before we > can turn on EL2? > > thanks > -- PMM >