Hi, On 27 July 2018 at 02:40, Chee, Tien Fong <tien.fong.c...@intel.com> wrote: > > On Thu, 2018-07-26 at 11:03 +0200, Michal Simek wrote: > > On 25.7.2018 18:03, Tom Rini wrote: > > > > > > On Wed, Jul 25, 2018 at 09:47:17AM -0600, Simon Glass wrote: > > > > > > > > Hi, > > > > > > > > On 25 July 2018 at 03:48, Michal Simek <michal.si...@xilinx.com> > > > > wrote: > > > > > > > > > > > > > > > On 25.7.2018 08:31, Chee, Tien Fong wrote: > > > > > > > > > > > > On Wed, 2018-07-18 at 16:48 +0200, Michal Simek wrote: > > > > > > > > > > > > > > On 6.7.2018 10:28, tien.fong.c...@intel.com wrote: > > > > > > > > > > > > > > > > > > > > > > > > From: Tien Fong Chee <tien.fong.c...@intel.com> > > > > > > > > > > > > [...] > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Also that DT binding is quite weird and I don't think you > > > > > > > will get > > > > > > > ACK > > > > > > > for this from device tree community at all. I think that > > > > > > > calling via > > > > > > > platdata and avoid DT nodes would be better way to go. > > > > > > Why do you think DT binding is weird? The DT is designed > > > > > > based on Simon > > > > > > proposal, and i believe following the rules in DTS spec. > > > > > > There are some DT benefits with current design, i think > > > > > > someone may be > > > > > > maintainer need to made the final decision on the design. > > > > > It is software configuration in file which should mostly > > > > > describe > > > > > hardware and state for hardware configuration. > > > > > > > > > > Your fs_loader node is purely describe sw configuration which > > > > > shouldn't > > > > > be here. > > > > > You have there run time configuration via variables. I think > > > > > using only > > > > > this way is enough. Default variables will match what you would > > > > > want to > > > > > add to DT. > > > > I think DT makes sense in the U-Boot context. > > > > > > > > We don't have a user space to handle policy decisions, and the > > > > 'chosen' node is a good place to configure these common features. > > > > > > > > While you can argue that the partition or filesystem where an > > > > image > > > > comes from is a software config, it is something that has to be > > > > configured. It has impact on hardware too, since the FPGA has to > > > > get > > > > its firmware from somewhere. We use the chosen node to specify > > > > the > > > > UART to use, and this is no different. Again, we don't have user- > > > > space > > > > config files in U-Boot. > > > > > > > > This argument comes up from time to time and I'd really like to > > > > put it > > > > to bed for U-Boot. I understand that Linux has its own approach > > > > and > > > > rules, but in some cases they serve U-Boot poorly. > > > I want to second this as well. So long as we're using our prefix > > > and > > > we've thought through and discussed what we're trying to do here, > > > it's > > > OK to do things that might not be accepted for Linux. > > > > > I have not a problem with using chosen node with u-boot prefix > > properties and my colleague hopefully with finish work about moving > > u-boot,dm-pre-reloc; to chosen node where it should be (because > > current > > solution has also problem with ordering). > > > > In this loader case doc is saying that you can rewrite it with > > variables > > on the prompt (or via script). > > For cases that you want to autodetect platform and pass/load correct > > dtb > > which setup u-boot this can be problematic and using DT is could be > > considered as easier for use. > > > > In this case this is what was proposed: > > > > + fs_loader0: fs-loader@0 { > > + u-boot,dm-pre-reloc; > > + compatible = "u-boot,fs-loader"; > > + phandlepart = <&mmc 1>; > > + }; > > > > + fs_loader1: fs-loader@1 { > > + u-boot,dm-pre-reloc; > > + compatible = "u-boot,fs-loader"; > > + mtdpart = "UBI", > > + ubivol = "ubi0"; > > + }; > > > > u-boot,dm-pre-reloc; requires DM_FLAG_PRE_RELOC which is not setup > > for > > this driver - it means this should be here. > You are right, i missed this one. The intention of design enables user > to call any loader with default storage through the sequence number if > fs loader is not defined in chosen. For example, there is a case where > system loading the file from SDMMC, NAND and QSPI. > > > > compatible = "u-boot,fs-loader"; - bind and probe are empty that's > > why > > this is only used for filling platdata but driver has no user that's > > why > > this is unused till someone calls that functions. > > > > phandlepart/mtdpart/ubivol is just for setup. > There are some benefits with driver model: > 1. Saving space, calling when need. > 2. Handle memory allocation and deallocation automatically. > > > > For the first case you can just use in chosen node: > > u-boot,fs-loader = <&mmc 1>; > > > > And for UBIfs. I have never played with that but I expect it > > shouldn't > > be big problem to describe it differently too (something like) > > u-boot,fs-loader = <0 ubi0>; > Need consider description for UBIFS, using fs-loader seems not working > for UBIFS, since more arguments such as mtdpartition and mtd volume > need passing into driver. In order to avoid messing, fs_loader can act > the pointer to the chosen. > > Anyway, i have no strong opinion with driver designed via platdata or > driver model if we can resolve the problem for UBIFS and maintainers > agree with it. > > > > Then this driver/interface can stay in DT where it should stay. The > > only > > thing is how this should be initialized because there is no > > compatible > > string. But you can do that via platdata for platforms which want to > > use > > this.
We should add a compatible string then :-) Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot