On Fri, 20 Sep 2019 at 23:23, Alistair Francis <alistai...@gmail.com> wrote: > On Thu, Sep 19, 2019 at 10:15 PM Bin Meng <bmeng...@gmail.com> wrote: > > I don't think we should mirror what is used on ARM virt board to > > create 2 flash for sifive_u. For ARM virt, there are 2 flashes because > > they need distinguish secure and non-secure. For sifive_u, only one is > > enough. > > I went back and forward about 1 or 2. Two seems more usable as maybe > someone wants to include two pflash files? The Xilinx machine also has > two so I'm kind of used to 2, but I'm not really fussed.
One of the reasons for having 2 on the Arm board (we do this even if we're not supporting secure vs non-secure) is that then you can use one for a fixed read-only BIOS image (backed by a file on the host filesystem shared between all VMs), and one backed by a read-write per-VM file providing permanent storage for BIOS environment variables. Notably UEFI likes to work this way, but the idea applies in theory to other boot loader or BIOSes I guess. I would suggest also checking with Markus that your code for instantiating the flash devices follows the current recommendations so the backing storage can be configured via -blockdev. (This is a fairly recent change from June or so; current-in-master virt and sbsa boards provide an example of doing the right thing, I think.) thanks -- PMM