* Move device tree generation from include file to bbclass @ 2015-04-15 12:33 Bach, Pascal 2015-04-15 13:13 ` [yocto] " Bruce Ashfield 0 siblings, 1 reply; 11+ messages in thread From: Bach, Pascal @ 2015-04-15 12:33 UTC (permalink / raw) To: yocto Hi As ARM now also moved to device tree it look like in future we will have more kernels that are using device tree then ones that are not. As far as I understand currently the generation of device trees is controlled via KERNEL_DEVICETREE and is handled in via an include file recipes-kernel/linux/linux-dtb.inc. I was thinking about moving this include into a class so it becomes easier to use. Before I dive into implementing something I would like some feedback from the community. I have the following variant in mind. Add the device tree generation to the current kernel.bbclass (or let kernel.bblcass inherit from a kernel-dtb.bbclass). This way all kernels would automatically be DT enabled. The class would check if KERNEL_DEVICETREE is set and generate device trees based on this information. For boards that don't have KERNEL_DEVICETREE set the class would do nothing and the behavior is like before. The advantage I see with this approach is that the only thing a user needs to do is to set KERNEL_DEVICETREE in the board and make sure the device trees are available in the kernel they like to build. I appreciate your feedback? Regards Pascal ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Move device tree generation from include file to bbclass 2015-04-15 12:33 Move device tree generation from include file to bbclass Bach, Pascal @ 2015-04-15 13:13 ` Bruce Ashfield 0 siblings, 0 replies; 11+ messages in thread From: Bruce Ashfield @ 2015-04-15 13:13 UTC (permalink / raw) To: Bach, Pascal, yocto, Patches and discussions about the oe-core layer On 2015-04-15 08:33 AM, Bach, Pascal wrote: > Hi > Adding oe-core, since that's the right place to have a discussion like this. > As ARM now also moved to device tree it look like in future we will have more kernels that are using device tree then ones that are not. True, but it has been like this for quite some time now :) > As far as I understand currently the generation of device trees is controlled via KERNEL_DEVICETREE and is handled in via an include file recipes-kernel/linux/linux-dtb.inc. > > I was thinking about moving this include into a class so it becomes easier to use. Before I dive into implementing something I would like some feedback from the community. The big trick with changing anything like this is compatibility with existing recipes. Whatever we do, existing recipes and layers shouldn't be broken .. or if they are broken, there should be a compelling technical reason to do so. > > I have the following variant in mind. > > Add the device tree generation to the current kernel.bbclass (or let kernel.bblcass inherit from a kernel-dtb.bbclass). > This way all kernels would automatically be DT enabled. > The class would check if KERNEL_DEVICETREE is set and generate device trees based on this information. For boards that don't have KERNEL_DEVICETREE set the class would do nothing and the behavior is like before. > The advantage I see with this approach is that the only thing a user needs to do is to set KERNEL_DEVICETREE in the board and make sure the device trees are available in the kernel they like to build. That's pretty much the experience that most users have now, since there's nearly always a kernel recipe created, that recipe includes linux-dtb.inc, and sets KERNEL_DEVICETREE. Everything else happens to build and package the device tree. Was there something specifically that was causing issues with the current way of building them ? Cheers, Bruce > > I appreciate your feedback? > > Regards > Pascal > ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [yocto] Move device tree generation from include file to bbclass @ 2015-04-15 13:13 ` Bruce Ashfield 0 siblings, 0 replies; 11+ messages in thread From: Bruce Ashfield @ 2015-04-15 13:13 UTC (permalink / raw) To: Bach, Pascal, yocto, Patches and discussions about the oe-core layer On 2015-04-15 08:33 AM, Bach, Pascal wrote: > Hi > Adding oe-core, since that's the right place to have a discussion like this. > As ARM now also moved to device tree it look like in future we will have more kernels that are using device tree then ones that are not. True, but it has been like this for quite some time now :) > As far as I understand currently the generation of device trees is controlled via KERNEL_DEVICETREE and is handled in via an include file recipes-kernel/linux/linux-dtb.inc. > > I was thinking about moving this include into a class so it becomes easier to use. Before I dive into implementing something I would like some feedback from the community. The big trick with changing anything like this is compatibility with existing recipes. Whatever we do, existing recipes and layers shouldn't be broken .. or if they are broken, there should be a compelling technical reason to do so. > > I have the following variant in mind. > > Add the device tree generation to the current kernel.bbclass (or let kernel.bblcass inherit from a kernel-dtb.bbclass). > This way all kernels would automatically be DT enabled. > The class would check if KERNEL_DEVICETREE is set and generate device trees based on this information. For boards that don't have KERNEL_DEVICETREE set the class would do nothing and the behavior is like before. > The advantage I see with this approach is that the only thing a user needs to do is to set KERNEL_DEVICETREE in the board and make sure the device trees are available in the kernel they like to build. That's pretty much the experience that most users have now, since there's nearly always a kernel recipe created, that recipe includes linux-dtb.inc, and sets KERNEL_DEVICETREE. Everything else happens to build and package the device tree. Was there something specifically that was causing issues with the current way of building them ? Cheers, Bruce > > I appreciate your feedback? > > Regards > Pascal > ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Move device tree generation from include file to bbclass 2015-04-15 13:13 ` [yocto] " Bruce Ashfield (?) @ 2015-04-15 15:22 ` Nikolay Dimitrov 2015-04-15 15:26 ` [yocto] " Bruce Ashfield -1 siblings, 1 reply; 11+ messages in thread From: Nikolay Dimitrov @ 2015-04-15 15:22 UTC (permalink / raw) To: Bruce Ashfield; +Cc: yocto, Patches and discussions about the oe-core layer Hi Bruce, On 04/15/2015 04:13 PM, Bruce Ashfield wrote: > On 2015-04-15 08:33 AM, Bach, Pascal wrote: >> Hi >> > > Adding oe-core, since that's the right place to have a discussion > like this. > >> As ARM now also moved to device tree it look like in future we will >> have more kernels that are using device tree then ones that are >> not. > > True, but it has been like this for quite some time now :) > >> As far as I understand currently the generation of device trees is >> controlled via KERNEL_DEVICETREE and is handled in via an include >> file recipes-kernel/linux/linux-dtb.inc. >> >> I was thinking about moving this include into a class so it becomes >> easier to use. Before I dive into implementing something I would >> like some feedback from the community. > > The big trick with changing anything like this is compatibility with > existing recipes. Whatever we do, existing recipes and layers > shouldn't be broken .. or if they are broken, there should be a > compelling technical reason to do so. > >> >> I have the following variant in mind. >> >> Add the device tree generation to the current kernel.bbclass (or >> let kernel.bblcass inherit from a kernel-dtb.bbclass). This way all >> kernels would automatically be DT enabled. The class would check if >> KERNEL_DEVICETREE is set and generate device trees based on this >> information. For boards that don't have KERNEL_DEVICETREE set the >> class would do nothing and the behavior is like before. The >> advantage I see with this approach is that the only thing a user >> needs to do is to set KERNEL_DEVICETREE in the board and make sure >> the device trees are available in the kernel they like to build. > > That's pretty much the experience that most users have now, since > there's nearly always a kernel recipe created, that recipe includes > linux-dtb.inc, and sets KERNEL_DEVICETREE. As far as I understood, Pascal's idea is to remove the need for user recipes to include linux-dtb.inc, and provide this functionality via inheritance. > Everything else happens to build and package the device tree. > > Was there something specifically that was causing issues with the > current way of building them ? > > Cheers, > > Bruce > >> >> I appreciate your feedback? >> >> Regards Pascal >> > Regards, Nikolay ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Move device tree generation from include file to bbclass 2015-04-15 15:22 ` Nikolay Dimitrov @ 2015-04-15 15:26 ` Bruce Ashfield 0 siblings, 0 replies; 11+ messages in thread From: Bruce Ashfield @ 2015-04-15 15:26 UTC (permalink / raw) To: Nikolay Dimitrov; +Cc: yocto, Patches and discussions about the oe-core layer On Wed, Apr 15, 2015 at 11:22 AM, Nikolay Dimitrov <picmaster@mail.bg> wrote: > Hi Bruce, > > > On 04/15/2015 04:13 PM, Bruce Ashfield wrote: >> >> On 2015-04-15 08:33 AM, Bach, Pascal wrote: >>> >>> Hi >>> >> >> Adding oe-core, since that's the right place to have a discussion >> like this. >> >>> As ARM now also moved to device tree it look like in future we will >>> have more kernels that are using device tree then ones that are >>> not. >> >> >> True, but it has been like this for quite some time now :) >> >>> As far as I understand currently the generation of device trees is >>> controlled via KERNEL_DEVICETREE and is handled in via an include >>> file recipes-kernel/linux/linux-dtb.inc. >>> >>> I was thinking about moving this include into a class so it becomes >>> easier to use. Before I dive into implementing something I would >>> like some feedback from the community. >> >> >> The big trick with changing anything like this is compatibility with >> existing recipes. Whatever we do, existing recipes and layers >> shouldn't be broken .. or if they are broken, there should be a >> compelling technical reason to do so. >> >>> >>> I have the following variant in mind. >>> >>> Add the device tree generation to the current kernel.bbclass (or >>> let kernel.bblcass inherit from a kernel-dtb.bbclass). This way all >>> kernels would automatically be DT enabled. The class would check if >>> KERNEL_DEVICETREE is set and generate device trees based on this >>> information. For boards that don't have KERNEL_DEVICETREE set the >>> class would do nothing and the behavior is like before. The >>> advantage I see with this approach is that the only thing a user >>> needs to do is to set KERNEL_DEVICETREE in the board and make sure >>> the device trees are available in the kernel they like to build. >> >> >> That's pretty much the experience that most users have now, since >> there's nearly always a kernel recipe created, that recipe includes >> linux-dtb.inc, and sets KERNEL_DEVICETREE. > > > As far as I understood, Pascal's idea is to remove the need for user > recipes to include linux-dtb.inc, and provide this functionality via > inheritance. That is obvious. My questions are around "why". There's no big technical advantage, and if you remove that existing file, you break existing recipes. Which means you need to leave a stub in place. So without a technical advantage, it's churn for the sake of churn. Bruce > >> Everything else happens to build and package the device tree. >> >> Was there something specifically that was causing issues with the >> current way of building them ? >> >> Cheers, >> >> Bruce >> >>> >>> I appreciate your feedback? >>> >>> Regards Pascal >>> >> > > Regards, > Nikolay > > -- > _______________________________________________ > yocto mailing list > yocto@yoctoproject.org > https://lists.yoctoproject.org/listinfo/yocto -- "Thou shalt not follow the NULL pointer, for chaos and madness await thee at its end" ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [yocto] Move device tree generation from include file to bbclass @ 2015-04-15 15:26 ` Bruce Ashfield 0 siblings, 0 replies; 11+ messages in thread From: Bruce Ashfield @ 2015-04-15 15:26 UTC (permalink / raw) To: Nikolay Dimitrov; +Cc: yocto, Patches and discussions about the oe-core layer On Wed, Apr 15, 2015 at 11:22 AM, Nikolay Dimitrov <picmaster@mail.bg> wrote: > Hi Bruce, > > > On 04/15/2015 04:13 PM, Bruce Ashfield wrote: >> >> On 2015-04-15 08:33 AM, Bach, Pascal wrote: >>> >>> Hi >>> >> >> Adding oe-core, since that's the right place to have a discussion >> like this. >> >>> As ARM now also moved to device tree it look like in future we will >>> have more kernels that are using device tree then ones that are >>> not. >> >> >> True, but it has been like this for quite some time now :) >> >>> As far as I understand currently the generation of device trees is >>> controlled via KERNEL_DEVICETREE and is handled in via an include >>> file recipes-kernel/linux/linux-dtb.inc. >>> >>> I was thinking about moving this include into a class so it becomes >>> easier to use. Before I dive into implementing something I would >>> like some feedback from the community. >> >> >> The big trick with changing anything like this is compatibility with >> existing recipes. Whatever we do, existing recipes and layers >> shouldn't be broken .. or if they are broken, there should be a >> compelling technical reason to do so. >> >>> >>> I have the following variant in mind. >>> >>> Add the device tree generation to the current kernel.bbclass (or >>> let kernel.bblcass inherit from a kernel-dtb.bbclass). This way all >>> kernels would automatically be DT enabled. The class would check if >>> KERNEL_DEVICETREE is set and generate device trees based on this >>> information. For boards that don't have KERNEL_DEVICETREE set the >>> class would do nothing and the behavior is like before. The >>> advantage I see with this approach is that the only thing a user >>> needs to do is to set KERNEL_DEVICETREE in the board and make sure >>> the device trees are available in the kernel they like to build. >> >> >> That's pretty much the experience that most users have now, since >> there's nearly always a kernel recipe created, that recipe includes >> linux-dtb.inc, and sets KERNEL_DEVICETREE. > > > As far as I understood, Pascal's idea is to remove the need for user > recipes to include linux-dtb.inc, and provide this functionality via > inheritance. That is obvious. My questions are around "why". There's no big technical advantage, and if you remove that existing file, you break existing recipes. Which means you need to leave a stub in place. So without a technical advantage, it's churn for the sake of churn. Bruce > >> Everything else happens to build and package the device tree. >> >> Was there something specifically that was causing issues with the >> current way of building them ? >> >> Cheers, >> >> Bruce >> >>> >>> I appreciate your feedback? >>> >>> Regards Pascal >>> >> > > Regards, > Nikolay > > -- > _______________________________________________ > yocto mailing list > yocto@yoctoproject.org > https://lists.yoctoproject.org/listinfo/yocto -- "Thou shalt not follow the NULL pointer, for chaos and madness await thee at its end" ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Move device tree generation from include file to bbclass 2015-04-15 15:26 ` [yocto] " Bruce Ashfield (?) @ 2015-04-15 16:12 ` Nikolay Dimitrov 2015-04-15 16:49 ` [yocto] " Bruce Ashfield 2015-04-16 7:41 ` [yocto] " Bach, Pascal -1 siblings, 2 replies; 11+ messages in thread From: Nikolay Dimitrov @ 2015-04-15 16:12 UTC (permalink / raw) To: Bruce Ashfield; +Cc: yocto, Patches and discussions about the oe-core layer Hi Bruce, On 04/15/2015 06:26 PM, Bruce Ashfield wrote: > On Wed, Apr 15, 2015 at 11:22 AM, Nikolay Dimitrov > <picmaster@mail.bg> wrote: >> Hi Bruce, >> >> >> On 04/15/2015 04:13 PM, Bruce Ashfield wrote: >>> >>> On 2015-04-15 08:33 AM, Bach, Pascal wrote: >>>> >>>> Hi >>>> >>> >>> Adding oe-core, since that's the right place to have a discussion >>> like this. >>> >>>> As ARM now also moved to device tree it look like in future we >>>> will have more kernels that are using device tree then ones >>>> that are not. >>> >>> >>> True, but it has been like this for quite some time now :) >>> >>>> As far as I understand currently the generation of device >>>> trees is controlled via KERNEL_DEVICETREE and is handled in via >>>> an include file recipes-kernel/linux/linux-dtb.inc. >>>> >>>> I was thinking about moving this include into a class so it >>>> becomes easier to use. Before I dive into implementing >>>> something I would like some feedback from the community. >>> >>> >>> The big trick with changing anything like this is compatibility >>> with existing recipes. Whatever we do, existing recipes and >>> layers shouldn't be broken .. or if they are broken, there >>> should be a compelling technical reason to do so. >>> >>>> >>>> I have the following variant in mind. >>>> >>>> Add the device tree generation to the current kernel.bbclass >>>> (or let kernel.bblcass inherit from a kernel-dtb.bbclass). >>>> This way all kernels would automatically be DT enabled. The >>>> class would check if KERNEL_DEVICETREE is set and generate >>>> device trees based on this information. For boards that don't >>>> have KERNEL_DEVICETREE set the class would do nothing and the >>>> behavior is like before. The advantage I see with this >>>> approach is that the only thing a user needs to do is to set >>>> KERNEL_DEVICETREE in the board and make sure the device trees >>>> are available in the kernel they like to build. >>> >>> >>> That's pretty much the experience that most users have now, since >>> there's nearly always a kernel recipe created, that recipe >>> includes linux-dtb.inc, and sets KERNEL_DEVICETREE. >> >> >> As far as I understood, Pascal's idea is to remove the need for >> user recipes to include linux-dtb.inc, and provide this >> functionality via inheritance. > > That is obvious. My questions are around "why". There's no big > technical advantage, and if you remove that existing file, you break > existing recipes. Which means you need to leave a stub in place. > > So without a technical advantage, it's churn for the sake of churn. Well, removing redundancy and simplifying users' recipes could be considered an advantage. Also, as the contents of linux-dtb.inc are going to be moved to bbclass, the file can be left empty, later maintainers remove the extra line from all users' recipes in following commits. I don't see breaking as an option. > Bruce > >> >>> Everything else happens to build and package the device tree. >>> >>> Was there something specifically that was causing issues with the >>> current way of building them ? >>> >>> Cheers, >>> >>> Bruce >>> >>>> >>>> I appreciate your feedback? >>>> >>>> Regards Pascal Kind regards, Nikolay ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Move device tree generation from include file to bbclass 2015-04-15 16:12 ` Nikolay Dimitrov @ 2015-04-15 16:49 ` Bruce Ashfield 2015-04-16 7:41 ` [yocto] " Bach, Pascal 1 sibling, 0 replies; 11+ messages in thread From: Bruce Ashfield @ 2015-04-15 16:49 UTC (permalink / raw) To: Nikolay Dimitrov; +Cc: yocto, Patches and discussions about the oe-core layer On Wed, Apr 15, 2015 at 12:12 PM, Nikolay Dimitrov <picmaster@mail.bg> wrote: > Hi Bruce, > > > On 04/15/2015 06:26 PM, Bruce Ashfield wrote: >> >> On Wed, Apr 15, 2015 at 11:22 AM, Nikolay Dimitrov >> <picmaster@mail.bg> wrote: >>> >>> Hi Bruce, >>> >>> >>> On 04/15/2015 04:13 PM, Bruce Ashfield wrote: >>>> >>>> >>>> On 2015-04-15 08:33 AM, Bach, Pascal wrote: >>>>> >>>>> >>>>> Hi >>>>> >>>> >>>> Adding oe-core, since that's the right place to have a discussion >>>> like this. >>>> >>>>> As ARM now also moved to device tree it look like in future we >>>>> will have more kernels that are using device tree then ones >>>>> that are not. >>>> >>>> >>>> >>>> True, but it has been like this for quite some time now :) >>>> >>>>> As far as I understand currently the generation of device >>>>> trees is controlled via KERNEL_DEVICETREE and is handled in via >>>>> an include file recipes-kernel/linux/linux-dtb.inc. >>>>> >>>>> I was thinking about moving this include into a class so it >>>>> becomes easier to use. Before I dive into implementing >>>>> something I would like some feedback from the community. >>>> >>>> >>>> >>>> The big trick with changing anything like this is compatibility >>>> with existing recipes. Whatever we do, existing recipes and >>>> layers shouldn't be broken .. or if they are broken, there >>>> should be a compelling technical reason to do so. >>>> >>>>> >>>>> I have the following variant in mind. >>>>> >>>>> Add the device tree generation to the current kernel.bbclass >>>>> (or let kernel.bblcass inherit from a kernel-dtb.bbclass). >>>>> This way all kernels would automatically be DT enabled. The >>>>> class would check if KERNEL_DEVICETREE is set and generate >>>>> device trees based on this information. For boards that don't >>>>> have KERNEL_DEVICETREE set the class would do nothing and the >>>>> behavior is like before. The advantage I see with this >>>>> approach is that the only thing a user needs to do is to set >>>>> KERNEL_DEVICETREE in the board and make sure the device trees >>>>> are available in the kernel they like to build. >>>> >>>> >>>> >>>> That's pretty much the experience that most users have now, since >>>> there's nearly always a kernel recipe created, that recipe >>>> includes linux-dtb.inc, and sets KERNEL_DEVICETREE. >>> >>> >>> >>> As far as I understood, Pascal's idea is to remove the need for >>> user recipes to include linux-dtb.inc, and provide this >>> functionality via inheritance. >> >> >> That is obvious. My questions are around "why". There's no big >> technical advantage, and if you remove that existing file, you break >> existing recipes. Which means you need to leave a stub in place. >> >> So without a technical advantage, it's churn for the sake of churn. > > > Well, removing redundancy and simplifying users' recipes could be > considered an advantage. Also, as the contents of linux-dtb.inc are > going to be moved to bbclass, the file can be left empty, later > maintainers remove the extra line from all users' recipes in following > commits. I don't see breaking as an option. And we could argue that having more inherits in the base is a bad thing for users that have no interest in device trees. One person's advantage is another's churn. I was looking for technical advantages or a plan for future features that might leverage this. Cheers, Bruce > >> Bruce >> >>> >>>> Everything else happens to build and package the device tree. >>>> >>>> Was there something specifically that was causing issues with the >>>> current way of building them ? >>>> >>>> Cheers, >>>> >>>> Bruce >>>> >>>>> >>>>> I appreciate your feedback? >>>>> >>>>> Regards Pascal > > > Kind regards, > Nikolay -- "Thou shalt not follow the NULL pointer, for chaos and madness await thee at its end" ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [yocto] Move device tree generation from include file to bbclass @ 2015-04-15 16:49 ` Bruce Ashfield 0 siblings, 0 replies; 11+ messages in thread From: Bruce Ashfield @ 2015-04-15 16:49 UTC (permalink / raw) To: Nikolay Dimitrov; +Cc: yocto, Patches and discussions about the oe-core layer On Wed, Apr 15, 2015 at 12:12 PM, Nikolay Dimitrov <picmaster@mail.bg> wrote: > Hi Bruce, > > > On 04/15/2015 06:26 PM, Bruce Ashfield wrote: >> >> On Wed, Apr 15, 2015 at 11:22 AM, Nikolay Dimitrov >> <picmaster@mail.bg> wrote: >>> >>> Hi Bruce, >>> >>> >>> On 04/15/2015 04:13 PM, Bruce Ashfield wrote: >>>> >>>> >>>> On 2015-04-15 08:33 AM, Bach, Pascal wrote: >>>>> >>>>> >>>>> Hi >>>>> >>>> >>>> Adding oe-core, since that's the right place to have a discussion >>>> like this. >>>> >>>>> As ARM now also moved to device tree it look like in future we >>>>> will have more kernels that are using device tree then ones >>>>> that are not. >>>> >>>> >>>> >>>> True, but it has been like this for quite some time now :) >>>> >>>>> As far as I understand currently the generation of device >>>>> trees is controlled via KERNEL_DEVICETREE and is handled in via >>>>> an include file recipes-kernel/linux/linux-dtb.inc. >>>>> >>>>> I was thinking about moving this include into a class so it >>>>> becomes easier to use. Before I dive into implementing >>>>> something I would like some feedback from the community. >>>> >>>> >>>> >>>> The big trick with changing anything like this is compatibility >>>> with existing recipes. Whatever we do, existing recipes and >>>> layers shouldn't be broken .. or if they are broken, there >>>> should be a compelling technical reason to do so. >>>> >>>>> >>>>> I have the following variant in mind. >>>>> >>>>> Add the device tree generation to the current kernel.bbclass >>>>> (or let kernel.bblcass inherit from a kernel-dtb.bbclass). >>>>> This way all kernels would automatically be DT enabled. The >>>>> class would check if KERNEL_DEVICETREE is set and generate >>>>> device trees based on this information. For boards that don't >>>>> have KERNEL_DEVICETREE set the class would do nothing and the >>>>> behavior is like before. The advantage I see with this >>>>> approach is that the only thing a user needs to do is to set >>>>> KERNEL_DEVICETREE in the board and make sure the device trees >>>>> are available in the kernel they like to build. >>>> >>>> >>>> >>>> That's pretty much the experience that most users have now, since >>>> there's nearly always a kernel recipe created, that recipe >>>> includes linux-dtb.inc, and sets KERNEL_DEVICETREE. >>> >>> >>> >>> As far as I understood, Pascal's idea is to remove the need for >>> user recipes to include linux-dtb.inc, and provide this >>> functionality via inheritance. >> >> >> That is obvious. My questions are around "why". There's no big >> technical advantage, and if you remove that existing file, you break >> existing recipes. Which means you need to leave a stub in place. >> >> So without a technical advantage, it's churn for the sake of churn. > > > Well, removing redundancy and simplifying users' recipes could be > considered an advantage. Also, as the contents of linux-dtb.inc are > going to be moved to bbclass, the file can be left empty, later > maintainers remove the extra line from all users' recipes in following > commits. I don't see breaking as an option. And we could argue that having more inherits in the base is a bad thing for users that have no interest in device trees. One person's advantage is another's churn. I was looking for technical advantages or a plan for future features that might leverage this. Cheers, Bruce > >> Bruce >> >>> >>>> Everything else happens to build and package the device tree. >>>> >>>> Was there something specifically that was causing issues with the >>>> current way of building them ? >>>> >>>> Cheers, >>>> >>>> Bruce >>>> >>>>> >>>>> I appreciate your feedback? >>>>> >>>>> Regards Pascal > > > Kind regards, > Nikolay -- "Thou shalt not follow the NULL pointer, for chaos and madness await thee at its end" ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Move device tree generation from include file to bbclass 2015-04-15 16:12 ` Nikolay Dimitrov @ 2015-04-16 7:41 ` Bach, Pascal 2015-04-16 7:41 ` [yocto] " Bach, Pascal 1 sibling, 0 replies; 11+ messages in thread From: Bach, Pascal @ 2015-04-16 7:41 UTC (permalink / raw) To: Nikolay Dimitrov, Bruce Ashfield Cc: yocto, Patches and discussions about the oe-core layer Hi Bruce, Hi Nikolay > >>>> > >>> > >>> Adding oe-core, since that's the right place to have a discussion > >>> like this. Thanks I'm never sure where to ask what :) > >>> > >>>> As ARM now also moved to device tree it look like in future we > will > >>>> have more kernels that are using device tree then ones that are > >>>> not. > >>> > >>> > >>> True, but it has been like this for quite some time now :) > >>> > >>>> As far as I understand currently the generation of device trees is > >>>> controlled via KERNEL_DEVICETREE and is handled in via an include > >>>> file recipes-kernel/linux/linux-dtb.inc. > >>>> > >>>> I was thinking about moving this include into a class so it > becomes > >>>> easier to use. Before I dive into implementing something I would > >>>> like some feedback from the community. > >>> > >>> > >>> The big trick with changing anything like this is compatibility > with > >>> existing recipes. Whatever we do, existing recipes and layers > >>> shouldn't be broken .. or if they are broken, there should be a > >>> compelling technical reason to do so. > >>> > >>>> > >>>> I have the following variant in mind. > >>>> > >>>> Add the device tree generation to the current kernel.bbclass (or > >>>> let kernel.bblcass inherit from a kernel-dtb.bbclass). > >>>> This way all kernels would automatically be DT enabled. The class > >>>> would check if KERNEL_DEVICETREE is set and generate device trees > >>>> based on this information. For boards that don't have > >>>> KERNEL_DEVICETREE set the class would do nothing and the behavior > >>>> is like before. The advantage I see with this approach is that the > >>>> only thing a user needs to do is to set KERNEL_DEVICETREE in the > >>>> board and make sure the device trees are available in the kernel > >>>> they like to build. > >>> > >>> > >>> That's pretty much the experience that most users have now, since > >>> there's nearly always a kernel recipe created, that recipe includes > >>> linux-dtb.inc, and sets KERNEL_DEVICETREE. > >> > >> > >> As far as I understood, Pascal's idea is to remove the need for user > >> recipes to include linux-dtb.inc, and provide this functionality via > >> inheritance. > > > > That is obvious. My questions are around "why". There's no big > > technical advantage, and if you remove that existing file, you break > > existing recipes. Which means you need to leave a stub in place. > > > > So without a technical advantage, it's churn for the sake of churn. > > Well, removing redundancy and simplifying users' recipes could be > considered an advantage. Also, as the contents of linux-dtb.inc are > going to be moved to bbclass, the file can be left empty, later > maintainers remove the extra line from all users' recipes in following > commits. I don't see breaking as an option. I completely agree that it is not worth to breaking existing recipes because of that. But I think the option with an empty linux-dtb.inc is acceptable. > >>> Everything else happens to build and package the device tree. > >>> > >>> Was there something specifically that was causing issues with the > >>> current way of building them ? There was no specific issue except that it feels like an unnecessary includes. And it seems a bit odd to me that most of the work of building the kernel is done in bbclasses, while just the dtb handling is done with an include. But of course it still is more of a cosmetic change than a real technical necessity. Regards Pascal ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [yocto] Move device tree generation from include file to bbclass @ 2015-04-16 7:41 ` Bach, Pascal 0 siblings, 0 replies; 11+ messages in thread From: Bach, Pascal @ 2015-04-16 7:41 UTC (permalink / raw) To: Nikolay Dimitrov, Bruce Ashfield Cc: yocto, Patches and discussions about the oe-core layer Hi Bruce, Hi Nikolay > >>>> > >>> > >>> Adding oe-core, since that's the right place to have a discussion > >>> like this. Thanks I'm never sure where to ask what :) > >>> > >>>> As ARM now also moved to device tree it look like in future we > will > >>>> have more kernels that are using device tree then ones that are > >>>> not. > >>> > >>> > >>> True, but it has been like this for quite some time now :) > >>> > >>>> As far as I understand currently the generation of device trees is > >>>> controlled via KERNEL_DEVICETREE and is handled in via an include > >>>> file recipes-kernel/linux/linux-dtb.inc. > >>>> > >>>> I was thinking about moving this include into a class so it > becomes > >>>> easier to use. Before I dive into implementing something I would > >>>> like some feedback from the community. > >>> > >>> > >>> The big trick with changing anything like this is compatibility > with > >>> existing recipes. Whatever we do, existing recipes and layers > >>> shouldn't be broken .. or if they are broken, there should be a > >>> compelling technical reason to do so. > >>> > >>>> > >>>> I have the following variant in mind. > >>>> > >>>> Add the device tree generation to the current kernel.bbclass (or > >>>> let kernel.bblcass inherit from a kernel-dtb.bbclass). > >>>> This way all kernels would automatically be DT enabled. The class > >>>> would check if KERNEL_DEVICETREE is set and generate device trees > >>>> based on this information. For boards that don't have > >>>> KERNEL_DEVICETREE set the class would do nothing and the behavior > >>>> is like before. The advantage I see with this approach is that the > >>>> only thing a user needs to do is to set KERNEL_DEVICETREE in the > >>>> board and make sure the device trees are available in the kernel > >>>> they like to build. > >>> > >>> > >>> That's pretty much the experience that most users have now, since > >>> there's nearly always a kernel recipe created, that recipe includes > >>> linux-dtb.inc, and sets KERNEL_DEVICETREE. > >> > >> > >> As far as I understood, Pascal's idea is to remove the need for user > >> recipes to include linux-dtb.inc, and provide this functionality via > >> inheritance. > > > > That is obvious. My questions are around "why". There's no big > > technical advantage, and if you remove that existing file, you break > > existing recipes. Which means you need to leave a stub in place. > > > > So without a technical advantage, it's churn for the sake of churn. > > Well, removing redundancy and simplifying users' recipes could be > considered an advantage. Also, as the contents of linux-dtb.inc are > going to be moved to bbclass, the file can be left empty, later > maintainers remove the extra line from all users' recipes in following > commits. I don't see breaking as an option. I completely agree that it is not worth to breaking existing recipes because of that. But I think the option with an empty linux-dtb.inc is acceptable. > >>> Everything else happens to build and package the device tree. > >>> > >>> Was there something specifically that was causing issues with the > >>> current way of building them ? There was no specific issue except that it feels like an unnecessary includes. And it seems a bit odd to me that most of the work of building the kernel is done in bbclasses, while just the dtb handling is done with an include. But of course it still is more of a cosmetic change than a real technical necessity. Regards Pascal ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2015-04-16 7:49 UTC | newest] Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2015-04-15 12:33 Move device tree generation from include file to bbclass Bach, Pascal 2015-04-15 13:13 ` Bruce Ashfield 2015-04-15 13:13 ` [yocto] " Bruce Ashfield 2015-04-15 15:22 ` Nikolay Dimitrov 2015-04-15 15:26 ` Bruce Ashfield 2015-04-15 15:26 ` [yocto] " Bruce Ashfield 2015-04-15 16:12 ` Nikolay Dimitrov 2015-04-15 16:49 ` Bruce Ashfield 2015-04-15 16:49 ` [yocto] " Bruce Ashfield 2015-04-16 7:41 ` Bach, Pascal 2015-04-16 7:41 ` [yocto] " Bach, Pascal
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