On Fri, Jan 25, 2019 at 10:31:20AM +0100, Alexander Graf wrote: > > > On 25.01.19 10:18, AKASHI Takahiro wrote: > > On Fri, Jan 25, 2019 at 09:52:31AM +0100, Alexander Graf wrote: > >> > >> > >> On 25.01.19 09:27, AKASHI Takahiro wrote: > >>> Alex, > >>> > >>> On Wed, Jan 23, 2019 at 10:51:29AM +0100, Alexander Graf wrote: > >>>> On 01/22/2019 08:39 PM, Simon Glass wrote: > >>>>> Hi Alex, > >>>>> > >>>>> On Tue, 22 Jan 2019 at 22:08, Alexander Graf <ag...@suse.de> wrote: > >>>>>> > >>>>>> > >>>>>> On 22.01.19 09:29, AKASHI Takahiro wrote: > >>>>>>> Alex, Simon, > >>>>>>> > >>>>>>> Apologies for my slow response on this matter, > >>>>>>> > >>>>>>> On Fri, Jan 11, 2019 at 08:57:05AM +0100, Alexander Graf wrote: > >>>>>>>> > >>>>>>>> On 11.01.19 05:29, AKASHI Takahiro wrote: > >>>>>>>>> Alex, Heinrich and Simon, > >>>>>>>>> > >>>>>>>>> Thank you for your comments, they are all valuable but also make me > >>>>>>>>> confused as different people have different requirements :) > >>>>>>>>> I'm not sure that all of us share the same *ultimate* goal here. > >>>>>>>> The shared ultimate goal is to "merge" (as Simon put it) dm and efi > >>>>>>>> objects. > >>>>>>> I don't still understand what "merge" means very well. > >>>>>> It basically means that "struct efi_object" moves into "struct > >>>>>> udevice". > >>>>>> Every udevice instance of type UCLASS_BLK would expose the block and > >>>>>> device_path protocols. > >>>>>> > >>>>>> This will be a slightly bigger rework, but eventually allows us to > >>>>>> basically get rid of efi_init_obj_list() I think. > >>>>> I envisaged something like: > >>>>> > >>>>> - EFI objects have their own UCLASS_EFI uclass > >>>> > >>>> ... and then we need to create our own sub object model around the > >>>> UCLASS_EFI devices again. I' not convinced that's a great idea yet :). I > >>>> really see little reason not to just expose every dm device as EFI > >>>> handle. > >>>> Things would plug in quite naturally I think. > >>> > >>> You said that the ultimate goal is to remove all efi_object data. > >>> Do you think that all the existing efi_object can be mapped to > >>> one of existing u-boot uclass devices? > >>> > >>> If so, what would be an real entity of a UEFI handle? > >>> struct udevice *? > >>> > >>> But Simon seems not to agree to adding any UEFI-specific members > >>> in struct udevice. > >> > >> I think we'll have to experiment with both approaches. I personally > >> would like to have struct udevice * be the UEFI handle, yes. > >> > >>> > >>>> But either way, someone would need to sit down and prototype things to be > >>>> sure. > >>>> > >>> > >>> The most simplest prototype would include > >>> * event mechanism (just registration and execution of hook/handler) > >>> event: udevice creation (and deletion) > >>> * efi_disk hook for udevice(UCLASS_BLK) creation > >>> * modified block device's enumeration code, say, scsi_scan(), > >>> to add an event hook at udevice creation > >>> * removing efi_disk_register() from efi_init_obj_list() > >>> * Optionally(?) UCLASS_PARTITION > >>> (Partition udevices would be created in part_init().) > >> > >> Almost. > >> > >> The simplest prototype would be to add a struct efi_object into struct > >> udevice. Then whenever we're looping over efi_obj_list in the code, we > >> additionally loop over all udevices to find the handle. > > > > Ah, yes. You're going further :) > > > >> Then, we could slowly give the uclasses explicit knowledge of uefi > >> protocols. So most of the logic of efi_disk_register() would move into > >> (or get called by) drivers/block/blk-uclass.c:blk_create_device(). > > > > Via event? Otherwise, we cannot decouple u-boot and UEFI world. > > For a prototype, just make it explicit and see how far that gets us. > > >> Instead of creating diskobj and adding calling efi_add_handle(), we > >> could then just use existing data structure from the udevice (and its > >> platdata). > > > > I don't have good confidence that we can remove struct efi_disk_obj, > > at least, for the time being as some of its members are quite UEFI-specific. > > Maybe we can move them into struct blk_desc? It's a matter of > experimenting I guess. > > > > >> > >> Does this make sense? Less events, more implicity :). > > > > I'll go for it. > > Thanks a lot :). Feel free to pick an easier target for starters too if > you prefer.
Prototyping is done :) Since it was so easy and simple, now I'm thinking of implementing UCLASS_PARTITION. But it is not so straightforward as I expected, and it won't bring us lots of advantages. (I think that blk_desc should also support a partition in its own.) Once it gets working, may I send out a patch? -Takahiro Akashi > > Alex _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
