On Mon, Oct 10, 2022 at 06:16:28PM +0200, Ard Biesheuvel wrote: > On Mon, 10 Oct 2022 at 18:05, Sunil V L <suni...@ventanamicro.com> wrote: > > > > On Mon, Oct 10, 2022 at 05:29:15PM +0200, Ard Biesheuvel wrote: > > > On Mon, 10 Oct 2022 at 17:19, Sunil V L <suni...@ventanamicro.com> wrote: > > > > > > > > On Mon, Oct 10, 2022 at 12:39:21PM +0200, Ard Biesheuvel wrote: > > > > > On Mon, 10 Oct 2022 at 12:13, Sunil V L <suni...@ventanamicro.com> > > > > > wrote: > > > > > > > > > > > > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4076 > > > > > > > > > > > > RISC-V needs NorFlashDxe driver for qemu virt machine. The > > > > > > ArmPlatformPkg has this driver but migrating it to generic > > > > > > package like MdeModulePkg introduces circular dependencies. > > > > > > So, add a simplified version of the NorFlashDxe driver in > > > > > > OvmfPkg. > > > > > > > > > > > > > > > > So what is the difference between this simplified version and the old > > > > > version? And it is backed in QEMU by the same NOR flash emulation, > > > > > shouldn't we use this driver for ArmVirtQemu as well? > > > > > > > > I agree. If we can break the dependency on EmbeddedPkg due to > > > > NvVarStoreFormattedLib, then we can migrate to MdeModulePkg and all > > > > consumers can use the same driver which would be the best solution IMO. > > > > > > > > Could you please let me know why NvVarStoreFormattedLib is added > > > > in EmbeddedPkg instead of MdePkg or MdeModulePkg? Is it only for > > > > non-server class platforms? I don't see it doing much so not sure > > > > its use case. > > > > > > > > > > I think that library as well as the definition of > > > gEdkiiNvVarStoreFormattedGuid should be moved to MdeModulePkg. > > > > > > Then, we can look at moving NorFlashDxe in there as well. > > > > Great. Let me rework these patches then. > > > > > > But you haven't answered my question regarding how your version was > > > simplified. > > > > > > > Oh sorry. I forgot to modify the commit message but what I really meant > > was removing the code which depends upon PcdNorFlashCheckBlockLocked for > > virtual platforms. I thought it is useful only for real platforms and > > qemu doesn't emulate it. Let me know if I am wrong. > > Since the driver is copied for OVMF, I didn't want to add the PCD > > unnecessarily. > > > > What I would like to do is the following: > > - move NvVarstoreFormattedLib into MdeModulePkg (as you proposed already) > - create a new NorFlashDxe in Ovmf that is cleaned up, drops the > handling of locked blocks (as you suggest) and minimizes the number of > transitions between array mode and programming mode (i have some > patches i can share as a starting point) > - move ArmPlatformPkg's NorFlashDxe into its only remaining user, > which is is Platform/ARM in edk2-platforms (there are two more users > in edk2-platforms, but both are QEMU based on so they can switch to > the OVMF one)
Interesting. In that case, we can continue with current approach of copy in Ovmf and add the optimization. I was assuming you want the same driver for real and virtual platforms in MdeModulePkg :-). Sure, please share those optimization changes. I will create patches as you have outlined here. > > > > > Note that there is some room for improvement in that driver in > > > relation to execution under KVM: switching between programming mode > > > and array mode involves setting up/tearing down the KVM memslot, and > > > currently, the driver is far from optimized when it comes to > > > minimizing the number of transitions between read mode and write mode. > > > > I was not looking at optimizing it at this point of time. > > > > I understand. And yet you are already proposing a different version of > NorFlashDxe, and I don't want to clone the existing NorFlashDxe > without cleaning it up first. Understood. Thanks for your help. Thanks Sunil -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#94948): https://edk2.groups.io/g/devel/message/94948 Mute This Topic: https://groups.io/mt/94233050/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
