| Message ID | 20211026002344.405160-7-sjg@chromium.org |
|---|---|
| State | Changes Requested |
| Delegated to: | Tom Rini |
| Headers | show |
| Series | fdt: Make OF_BOARD a boolean option | expand |
On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: > > Add this file, generated from qemu, so there is a reference devicetree > in the U-Boot tree. > > Signed-off-by: Simon Glass <sjg@chromium.org> Note that the dtb you get from QEMU is only guaranteed to work if: 1) you run it on the exact same QEMU version you generated it with 2) you pass QEMU the exact same command line arguments you used when you generated it thanks -- PMM
Hi Peter, On Mon, 1 Nov 2021 at 04:48, Peter Maydell <peter.maydell@linaro.org> wrote: > > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: > > > > Add this file, generated from qemu, so there is a reference devicetree > > in the U-Boot tree. > > > > Signed-off-by: Simon Glass <sjg@chromium.org> > > Note that the dtb you get from QEMU is only guaranteed to work if: > 1) you run it on the exact same QEMU version you generated it with > 2) you pass QEMU the exact same command line arguments you used > when you generated it Yes, I certainly understand that. In general this is not safe, but in practice it works well enough for development and CI. I am able to use QEMU versions that differ by two years, partly because I am not trying to do anything clever. I have sent a patch to add an indication of where the devicetree came from, to help with visibility on this. Regards, Simon
Hi Simon Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a écrit : > Hi Peter, > > On Mon, 1 Nov 2021 at 04:48, Peter Maydell <peter.maydell@linaro.org> > wrote: > > > > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: > > > > > > Add this file, generated from qemu, so there is a reference devicetree > > > in the U-Boot tree. > > > > > > Signed-off-by: Simon Glass <sjg@chromium.org> > > > > Note that the dtb you get from QEMU is only guaranteed to work if: > > 1) you run it on the exact same QEMU version you generated it with > > 2) you pass QEMU the exact same command line arguments you used > > when you generated it > > Yes, I certainly understand that. In general this is not safe, but in > practice it works well enough for development and CI. You recognize that you hijack a product directory with development hack facility. There is a test directory to keep things clear. There can be a dev-dts or something similar for Dev time tools. I have only seen push back on those fake dts files in the dts directory: I guess that unless someone strongly favors a continuation of the discussion, you may consider re-shaping the proposal to address concerns. > I am able to use > QEMU versions that differ by two years, partly because I am not trying > to do anything clever. > > I have sent a patch to add an indication of where the devicetree came > from, to help with visibility on this. > > Regards, > Simon >
On Mon, Nov 01, 2021 at 06:33:35PM +0100, François Ozog wrote: > Hi Simon > > Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a écrit : > > > Hi Peter, > > > > On Mon, 1 Nov 2021 at 04:48, Peter Maydell <peter.maydell@linaro.org> > > wrote: > > > > > > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: > > > > > > > > Add this file, generated from qemu, so there is a reference devicetree > > > > in the U-Boot tree. > > > > > > > > Signed-off-by: Simon Glass <sjg@chromium.org> > > > > > > Note that the dtb you get from QEMU is only guaranteed to work if: > > > 1) you run it on the exact same QEMU version you generated it with > > > 2) you pass QEMU the exact same command line arguments you used > > > when you generated it > > > > Yes, I certainly understand that. In general this is not safe, but in > > practice it works well enough for development and CI. > > You recognize that you hijack a product directory with development hack > facility. There is a test directory to keep things clear. There can be a > dev-dts or something similar for Dev time tools. > I have only seen push back on those fake dts files in the dts directory: I > guess that unless someone strongly favors a continuation of the discussion, > you may consider re-shaping the proposal to address concerns. Yes. We need to document how to make development easier. But I'm still not on board with the notion of including DTS files for platforms where the source of truth for the DTB is elsewhere. That's going to bring us a lot more pain. It is important to make sure our "develop our project" workflow is sane and relatively pain free. But that needs to not come by making sacrifices to the "use our project" outcome. I would hope for example that the new Pi zero platform is just dtb changes, as far as the linux kernel is concerned which means that for rpi_arm64 (which uses run time dtb) it also just works. And that's what we want to see.
Hi François, On Mon, 1 Nov 2021 at 11:33, François Ozog <francois.ozog@linaro.org> wrote: > > Hi Simon > > Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a écrit : >> >> Hi Peter, >> >> On Mon, 1 Nov 2021 at 04:48, Peter Maydell <peter.maydell@linaro.org> wrote: >> > >> > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: >> > > >> > > Add this file, generated from qemu, so there is a reference devicetree >> > > in the U-Boot tree. >> > > >> > > Signed-off-by: Simon Glass <sjg@chromium.org> >> > >> > Note that the dtb you get from QEMU is only guaranteed to work if: >> > 1) you run it on the exact same QEMU version you generated it with >> > 2) you pass QEMU the exact same command line arguments you used >> > when you generated it >> >> Yes, I certainly understand that. In general this is not safe, but in >> practice it works well enough for development and CI. > > You recognize that you hijack a product directory with development hack facility. There is a test directory to keep things clear. There can be a dev-dts or something similar for Dev time tools. > I have only seen push back on those fake dts files in the dts directory: I guess that unless someone strongly favors a continuation of the discussion, you may consider re-shaping the proposal to address concerns. As stated previously, I would like to have at least a sample DT in-tree for all boards. I cannot see another way to get the Kconfig options in line. If we are able to put these files somewhere else in the future and get them out of U-Boot, with perhaps just an overlay for development purposes, I'd be keen to see it. But for now, this is where we are, I believe. In this particular case, this is not just a dev hack. It is also for CI tests which need to use a devicetree. See for example here: https://patchwork.ozlabs.org/project/uboot/patch/20211101011734.1614781-15-sjg@chromium.org/ https://patchwork.ozlabs.org/project/uboot/patch/20211101011734.1614781-24-sjg@chromium.org/ >> >> I am able to use >> QEMU versions that differ by two years, partly because I am not trying >> to do anything clever. >> >> I have sent a patch to add an indication of where the devicetree came >> from, to help with visibility on this. Regards, Simon
Hi Tom, On Mon, 1 Nov 2021 at 12:07, Tom Rini <trini@konsulko.com> wrote: > > On Mon, Nov 01, 2021 at 06:33:35PM +0100, François Ozog wrote: > > Hi Simon > > > > Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a écrit : > > > > > Hi Peter, > > > > > > On Mon, 1 Nov 2021 at 04:48, Peter Maydell <peter.maydell@linaro.org> > > > wrote: > > > > > > > > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: > > > > > > > > > > Add this file, generated from qemu, so there is a reference devicetree > > > > > in the U-Boot tree. > > > > > > > > > > Signed-off-by: Simon Glass <sjg@chromium.org> > > > > > > > > Note that the dtb you get from QEMU is only guaranteed to work if: > > > > 1) you run it on the exact same QEMU version you generated it with > > > > 2) you pass QEMU the exact same command line arguments you used > > > > when you generated it > > > > > > Yes, I certainly understand that. In general this is not safe, but in > > > practice it works well enough for development and CI. > > > > You recognize that you hijack a product directory with development hack > > facility. There is a test directory to keep things clear. There can be a > > dev-dts or something similar for Dev time tools. > > I have only seen push back on those fake dts files in the dts directory: I > > guess that unless someone strongly favors a continuation of the discussion, > > you may consider re-shaping the proposal to address concerns. > > Yes. We need to document how to make development easier. But I'm still > not on board with the notion of including DTS files for platforms where > the source of truth for the DTB is elsewhere. That's going to bring us > a lot more pain. Are you talking about QEMU specifically, or Raspberry Pi? How can we get this resolved? I very much want to get to just having OF_SEPARATE and OF_EMBED as the only available build-time options, with OF_BOARD (and perhaps OF_PASSAGE) as something we can enable for runtime support. I feel that separating the build-time and run-time behaviour is very important. Over time perhaps we will have some success in upstreaming bindings, but for now we have what we have. There is still a lot of pushback on U-Boot having things in the devicetree, although I do see that softening somewhat. > > It is important to make sure our "develop our project" workflow is sane > and relatively pain free. But that needs to not come by making > sacrifices to the "use our project" outcome. I would hope for example > that the new Pi zero platform is just dtb changes, as far as the linux > kernel is concerned which means that for rpi_arm64 (which uses run time > dtb) it also just works. And that's what we want to see. So long as OF_BOARD is enabled then the flow should work as you expect. Regards, Simon
On Tue, Nov 02, 2021 at 08:59:45AM -0600, Simon Glass wrote: > Hi François, > > On Mon, 1 Nov 2021 at 11:33, François Ozog <francois.ozog@linaro.org> wrote: > > > > Hi Simon > > > > Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a écrit : > >> > >> Hi Peter, > >> > >> On Mon, 1 Nov 2021 at 04:48, Peter Maydell <peter.maydell@linaro.org> wrote: > >> > > >> > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: > >> > > > >> > > Add this file, generated from qemu, so there is a reference devicetree > >> > > in the U-Boot tree. > >> > > > >> > > Signed-off-by: Simon Glass <sjg@chromium.org> > >> > > >> > Note that the dtb you get from QEMU is only guaranteed to work if: > >> > 1) you run it on the exact same QEMU version you generated it with > >> > 2) you pass QEMU the exact same command line arguments you used > >> > when you generated it > >> > >> Yes, I certainly understand that. In general this is not safe, but in > >> practice it works well enough for development and CI. > > > > You recognize that you hijack a product directory with development hack facility. There is a test directory to keep things clear. There can be a dev-dts or something similar for Dev time tools. > > I have only seen push back on those fake dts files in the dts directory: I guess that unless someone strongly favors a continuation of the discussion, you may consider re-shaping the proposal to address concerns. > > As stated previously, I would like to have at least a sample DT > in-tree for all boards. I cannot see another way to get the Kconfig What's the point of having a sample when it's not going to always be correct or may be actively wrong and we can tell interested developers / users how to get the correct DTB/DTS to examine? > options in line. If we are able to put these files somewhere else in > the future and get them out of U-Boot, with perhaps just an overlay > for development purposes, I'd be keen to see it. But for now, this is > where we are, I believe. > > In this particular case, this is not just a dev hack. It is also for > CI tests which need to use a devicetree. See for example here: > > https://patchwork.ozlabs.org/project/uboot/patch/20211101011734.1614781-15-sjg@chromium.org/ > https://patchwork.ozlabs.org/project/uboot/patch/20211101011734.1614781-24-sjg@chromium.org/ This example would probably be better done on vexpress_ca9x4 where we do test in CI via QEMU but do not need to modify a device tree that is passed on to us, we already control the source of truth DTB in this case. And also yes, I'm behind on reviewing things I need to review.
On Tue, Nov 02, 2021 at 09:00:53AM -0600, Simon Glass wrote: > Hi Tom, > > On Mon, 1 Nov 2021 at 12:07, Tom Rini <trini@konsulko.com> wrote: > > > > On Mon, Nov 01, 2021 at 06:33:35PM +0100, François Ozog wrote: > > > Hi Simon > > > > > > Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a écrit : > > > > > > > Hi Peter, > > > > > > > > On Mon, 1 Nov 2021 at 04:48, Peter Maydell <peter.maydell@linaro.org> > > > > wrote: > > > > > > > > > > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: > > > > > > > > > > > > Add this file, generated from qemu, so there is a reference devicetree > > > > > > in the U-Boot tree. > > > > > > > > > > > > Signed-off-by: Simon Glass <sjg@chromium.org> > > > > > > > > > > Note that the dtb you get from QEMU is only guaranteed to work if: > > > > > 1) you run it on the exact same QEMU version you generated it with > > > > > 2) you pass QEMU the exact same command line arguments you used > > > > > when you generated it > > > > > > > > Yes, I certainly understand that. In general this is not safe, but in > > > > practice it works well enough for development and CI. > > > > > > You recognize that you hijack a product directory with development hack > > > facility. There is a test directory to keep things clear. There can be a > > > dev-dts or something similar for Dev time tools. > > > I have only seen push back on those fake dts files in the dts directory: I > > > guess that unless someone strongly favors a continuation of the discussion, > > > you may consider re-shaping the proposal to address concerns. > > > > Yes. We need to document how to make development easier. But I'm still > > not on board with the notion of including DTS files for platforms where > > the source of truth for the DTB is elsewhere. That's going to bring us > > a lot more pain. > > Are you talking about QEMU specifically, or Raspberry Pi? I was using two of the more common and readily available platforms where the source of truth for the DTS/DTB is not (and will not be) U-Boot. > How can we get this resolved? I very much want to get to just having > OF_SEPARATE and OF_EMBED as the only available build-time options, > with OF_BOARD (and perhaps OF_PASSAGE) as something we can enable for > runtime support. I feel that separating the build-time and run-time > behaviour is very important. Over time perhaps we will have some > success in upstreaming bindings, but for now we have what we have. > There is still a lot of pushback on U-Boot having things in the > devicetree, although I do see that softening somewhat. To reiterate, the uniform bit of feedback on this series has been that everyone else disagrees with your notion that we _must_ have a dts in-tree. > > It is important to make sure our "develop our project" workflow is sane > > and relatively pain free. But that needs to not come by making > > sacrifices to the "use our project" outcome. I would hope for example > > that the new Pi zero platform is just dtb changes, as far as the linux > > kernel is concerned which means that for rpi_arm64 (which uses run time > > dtb) it also just works. And that's what we want to see. > > So long as OF_BOARD is enabled then the flow should work as you expect. Then we need to get things spun such that we can build the platforms where the dtb is given to us, complete and correct, at run time, to not require an in-tree dts that's not going to be used. Documentation (another area we have much improved on these past few years and for which I am grateful for all of the effort behind!) is how we make the developer use-case for those platforms better.
Hi Tom, On Tue, 2 Nov 2021 at 11:28, Tom Rini <trini@konsulko.com> wrote: > > On Tue, Nov 02, 2021 at 09:00:53AM -0600, Simon Glass wrote: > > Hi Tom, > > > > On Mon, 1 Nov 2021 at 12:07, Tom Rini <trini@konsulko.com> wrote: > > > > > > On Mon, Nov 01, 2021 at 06:33:35PM +0100, François Ozog wrote: > > > > Hi Simon > > > > > > > > Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a écrit : > > > > > > > > > Hi Peter, > > > > > > > > > > On Mon, 1 Nov 2021 at 04:48, Peter Maydell <peter.maydell@linaro.org> > > > > > wrote: > > > > > > > > > > > > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: > > > > > > > > > > > > > > Add this file, generated from qemu, so there is a reference devicetree > > > > > > > in the U-Boot tree. > > > > > > > > > > > > > > Signed-off-by: Simon Glass <sjg@chromium.org> > > > > > > > > > > > > Note that the dtb you get from QEMU is only guaranteed to work if: > > > > > > 1) you run it on the exact same QEMU version you generated it with > > > > > > 2) you pass QEMU the exact same command line arguments you used > > > > > > when you generated it > > > > > > > > > > Yes, I certainly understand that. In general this is not safe, but in > > > > > practice it works well enough for development and CI. > > > > > > > > You recognize that you hijack a product directory with development hack > > > > facility. There is a test directory to keep things clear. There can be a > > > > dev-dts or something similar for Dev time tools. > > > > I have only seen push back on those fake dts files in the dts directory: I > > > > guess that unless someone strongly favors a continuation of the discussion, > > > > you may consider re-shaping the proposal to address concerns. > > > > > > Yes. We need to document how to make development easier. But I'm still > > > not on board with the notion of including DTS files for platforms where > > > the source of truth for the DTB is elsewhere. That's going to bring us > > > a lot more pain. > > > > Are you talking about QEMU specifically, or Raspberry Pi? > > I was using two of the more common and readily available platforms where > the source of truth for the DTS/DTB is not (and will not be) U-Boot. > > > How can we get this resolved? I very much want to get to just having > > OF_SEPARATE and OF_EMBED as the only available build-time options, > > with OF_BOARD (and perhaps OF_PASSAGE) as something we can enable for > > runtime support. I feel that separating the build-time and run-time > > behaviour is very important. Over time perhaps we will have some > > success in upstreaming bindings, but for now we have what we have. > > There is still a lot of pushback on U-Boot having things in the > > devicetree, although I do see that softening somewhat. > > > To reiterate, the uniform bit of feedback on this series has been that > everyone else disagrees with your notion that we _must_ have a dts > in-tree. [I would like everyone to take a deep breath and think about what this actually impacts. I argue the impact outside U-Boot is approximately zero. What are we actually discussing here?] A few have responded that they can just add the files. I think that is the case for everything except QEMU, right? I think even François agrees with the documentation argument. There is no real burden in adding the files so we can see what is going on, add a binman node, SPL nodes, etc. So I am going to stand my ground on that one. It affects: - highbank - qemu-ppce500 - rpi_4 - xilinx_versal_virt - octeontx - xenguest_arm64 - juno So that is just 7 boards that I want to add devicetree files for. I think that is reasonable and not a burden on these maintainers. Let me deal with QEMU. Let's imagine that we were in the state that I am proposing here, which we would be if I were a better devicetree maintainer for U-Boot and had not taken my eye off the ball, basically with my review of [1], where I should have pushed to get a response on the questions before it was applied. That might have triggered me to think about the implications of this at the time. Anyway, in the state that I am proposing, what problems would we have? 1. QEMU has a DT which only matches the 'standard' invocation as documented at [2] 2. QEMU may get out of date if there is a new release. I don't think (1) is really a problem. People will have to remove CONFIG_OF_BOARD from configs/qemu_arm_spl_defconfig (or the like) to get into this state, and we have a message now that prints out where the devicetree comes from ("separate" in this case): Core: 42 devices, 11 uclasses, devicetree: separate For (2), I tested QEMU 6.1.50 and the only difference from 4.2.1 (a year old) is: kaslr-seed = <0x2037f53d 0x42c279e8>; It doesn't affect anything here. It boots the lastest image fine. Just for interest I went back to 2.5.0 which is nearly 6 years old! There are a few differences like dma-coherent and gpio-keys being added, but again it boots fine. So in practice that doesn't seem to be a problem from what I can tell. 3. Anything else? For qemu_arm_spl, it *does not boot* unless the U-Boot SPL properties are present. There is no easy way to fix this. If we merge them into qemu with dumpdtb, etc. we are assuming that the node we want to update is present, so this is not really any better than having the devicetree in U-Boot. Actually I think it is worse, since who knows what changes might happen to the devicetree in QEMU which will stop U-Boot from working. QEMU cannot make changes that don't follow the bindings. U-Boot uses the bindings, so we are good. It just seems very clear to me that this approach is far superior to U-Boot to the wonky business that we have today. > > > > It is important to make sure our "develop our project" workflow is sane > > > and relatively pain free. But that needs to not come by making > > > sacrifices to the "use our project" outcome. I would hope for example > > > that the new Pi zero platform is just dtb changes, as far as the linux > > > kernel is concerned which means that for rpi_arm64 (which uses run time > > > dtb) it also just works. And that's what we want to see. > > > > So long as OF_BOARD is enabled then the flow should work as you expect. > > Then we need to get things spun such that we can build the platforms > where the dtb is given to us, complete and correct, at run time, to not > require an in-tree dts that's not going to be used. Documentation > (another area we have much improved on these past few years and for > which I am grateful for all of the effort behind!) is how we make the > developer use-case for those platforms better. I did not expect everyone to love this; this is how we got into the mess we are in. A few people thinking it would be expedient to just do their own thing. But I have come to this after an enormous amount of thought and much discussion. I think sometimes people imagine that I just throw things over the wall to get a reaction. That is not the case. We need some way to put U-Boot properties in there, at least until things change upstream and within U-Boot. That envisages tooling that is clearly not going to be in place for the upcoming release. For the test, how about I create a separate qemu build (which I have done, actually, qemu_arm_spl) and control the QEMU flags so we know it will boot. It is for CI so we can keep it in sync and deal with any breakages if people change things in QEMU (as above, this seems to be a theoretical problem). Again, please take a deep breath and consider how much this actually affects TF-A, QEMU, etc. I'd argue not at all. We are talking about a build-time devicetree in the U-Boot tree. We are not talking about disabling OF_BOARD or removing that option. Regards, Simon [1] http://patchwork.ozlabs.org/project/uboot/patch/20170402082520.32546-1-deymo@google.com/ [2] https://u-boot.readthedocs.io/en/latest/board/emulation/qemu-arm.html
Hi Tom, On Tue, 2 Nov 2021 at 10:57, Tom Rini <trini@konsulko.com> wrote: > > On Tue, Nov 02, 2021 at 08:59:45AM -0600, Simon Glass wrote: > > Hi François, > > > > On Mon, 1 Nov 2021 at 11:33, François Ozog <francois.ozog@linaro.org> wrote: > > > > > > Hi Simon > > > > > > Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a écrit : > > >> > > >> Hi Peter, > > >> > > >> On Mon, 1 Nov 2021 at 04:48, Peter Maydell <peter.maydell@linaro.org> wrote: > > >> > > > >> > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: > > >> > > > > >> > > Add this file, generated from qemu, so there is a reference devicetree > > >> > > in the U-Boot tree. > > >> > > > > >> > > Signed-off-by: Simon Glass <sjg@chromium.org> > > >> > > > >> > Note that the dtb you get from QEMU is only guaranteed to work if: > > >> > 1) you run it on the exact same QEMU version you generated it with > > >> > 2) you pass QEMU the exact same command line arguments you used > > >> > when you generated it > > >> > > >> Yes, I certainly understand that. In general this is not safe, but in > > >> practice it works well enough for development and CI. > > > > > > You recognize that you hijack a product directory with development hack facility. There is a test directory to keep things clear. There can be a dev-dts or something similar for Dev time tools. > > > I have only seen push back on those fake dts files in the dts directory: I guess that unless someone strongly favors a continuation of the discussion, you may consider re-shaping the proposal to address concerns. > > > > As stated previously, I would like to have at least a sample DT > > in-tree for all boards. I cannot see another way to get the Kconfig > > What's the point of having a sample when it's not going to always be > correct or may be actively wrong and we can tell interested developers / > users how to get the correct DTB/DTS to examine? > > > options in line. If we are able to put these files somewhere else in > > the future and get them out of U-Boot, with perhaps just an overlay > > for development purposes, I'd be keen to see it. But for now, this is > > where we are, I believe. > > > > In this particular case, this is not just a dev hack. It is also for > > CI tests which need to use a devicetree. See for example here: > > > > https://patchwork.ozlabs.org/project/uboot/patch/20211101011734.1614781-15-sjg@chromium.org/ > > https://patchwork.ozlabs.org/project/uboot/patch/20211101011734.1614781-24-sjg@chromium.org/ > > This example would probably be better done on vexpress_ca9x4 where we do > test in CI via QEMU but do not need to modify a device tree that is > passed on to us, we already control the source of truth DTB in this > case. But that board: - uses OF_EMBED, which it should not - does not use SPL, which I need > > And also yes, I'm behind on reviewing things I need to review. Aren't we all...I can't even keep up with these threads. Regards, Simon
Hi Simon Le mer. 3 nov. 2021 à 02:30, Simon Glass <sjg@chromium.org> a écrit : > Hi Tom, > > On Tue, 2 Nov 2021 at 11:28, Tom Rini <trini@konsulko.com> wrote: > > > > On Tue, Nov 02, 2021 at 09:00:53AM -0600, Simon Glass wrote: > > > Hi Tom, > > > > > > On Mon, 1 Nov 2021 at 12:07, Tom Rini <trini@konsulko.com> wrote: > > > > > > > > On Mon, Nov 01, 2021 at 06:33:35PM +0100, François Ozog wrote: > > > > > Hi Simon > > > > > > > > > > Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a > écrit : > > > > > > > > > > > Hi Peter, > > > > > > > > > > > > On Mon, 1 Nov 2021 at 04:48, Peter Maydell < > peter.maydell@linaro.org> > > > > > > wrote: > > > > > > > > > > > > > > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> > wrote: > > > > > > > > > > > > > > > > Add this file, generated from qemu, so there is a reference > devicetree > > > > > > > > in the U-Boot tree. > > > > > > > > > > > > > > > > Signed-off-by: Simon Glass <sjg@chromium.org> > > > > > > > > > > > > > > Note that the dtb you get from QEMU is only guaranteed to work > if: > > > > > > > 1) you run it on the exact same QEMU version you generated it > with > > > > > > > 2) you pass QEMU the exact same command line arguments you > used > > > > > > > when you generated it > > > > > > > > > > > > Yes, I certainly understand that. In general this is not safe, > but in > > > > > > practice it works well enough for development and CI. > > > > > > > > > > You recognize that you hijack a product directory with development > hack > > > > > facility. There is a test directory to keep things clear. There > can be a > > > > > dev-dts or something similar for Dev time tools. > > > > > I have only seen push back on those fake dts files in the dts > directory: I > > > > > guess that unless someone strongly favors a continuation of the > discussion, > > > > > you may consider re-shaping the proposal to address concerns. > > > > > > > > Yes. We need to document how to make development easier. But I'm > still > > > > not on board with the notion of including DTS files for platforms > where > > > > the source of truth for the DTB is elsewhere. That's going to bring > us > > > > a lot more pain. > > > > > > Are you talking about QEMU specifically, or Raspberry Pi? > > > > I was using two of the more common and readily available platforms where > > the source of truth for the DTS/DTB is not (and will not be) U-Boot. > > > > > How can we get this resolved? I very much want to get to just having > > > OF_SEPARATE and OF_EMBED as the only available build-time options, > > > with OF_BOARD (and perhaps OF_PASSAGE) as something we can enable for > > > runtime support. I feel that separating the build-time and run-time > > > behaviour is very important. Over time perhaps we will have some > > > success in upstreaming bindings, but for now we have what we have. > > > There is still a lot of pushback on U-Boot having things in the > > > devicetree, although I do see that softening somewhat. > > > > > > To reiterate, the uniform bit of feedback on this series has been that > > everyone else disagrees with your notion that we _must_ have a dts > > in-tree. > > [I would like everyone to take a deep breath and think about what this > actually impacts. I argue the impact outside U-Boot is approximately > zero. What are we actually discussing here?] > > A few have responded that they can just add the files. I think that is > the case for everything except QEMU, right? I think even François > agrees with the documentation argument. I do providing that the sample goes into documentation, not actionable as a build artifact in the dts directory. > There is no real burden in > adding the files so we can see what is going on, add a binman node, > SPL nodes, etc. > > So I am going to stand my ground on that one. It affects: > > - highbank > - qemu-ppce500 > - rpi_4 > - xilinx_versal_virt > - octeontx > - xenguest_arm64 > - juno > > So that is just 7 boards that I want to add devicetree files for. I > think that is reasonable and not a burden on these maintainers. > > Let me deal with QEMU. > > Let's imagine that we were in the state that I am proposing here, > which we would be if I were a better devicetree maintainer for U-Boot > and had not taken my eye off the ball, basically with my review of > [1], where I should have pushed to get a response on the questions > before it was applied. That might have triggered me to think about the > implications of this at the time. > > Anyway, in the state that I am proposing, what problems would we have? > > 1. QEMU has a DT which only matches the 'standard' invocation as > documented at [2] > > 2. QEMU may get out of date if there is a new release. > > I don't think (1) is really a problem. People will have to remove > CONFIG_OF_BOARD from configs/qemu_arm_spl_defconfig (or the like) to > get into this state, and we have a message now that prints out where > the devicetree comes from ("separate" in this case): > > Core: 42 devices, 11 uclasses, devicetree: separate > > For (2), I tested QEMU 6.1.50 and the only difference from 4.2.1 (a > year old) is: > > kaslr-seed = <0x2037f53d 0x42c279e8>; > > It doesn't affect anything here. It boots the lastest image fine. > > Just for interest I went back to 2.5.0 which is nearly 6 years old! > There are a few differences like dma-coherent and gpio-keys being > added, but again it boots fine. > > So in practice that doesn't seem to be a problem from what I can tell. > You are essentially saying “I don’t care about the system design, this DTS simplifies my development work for U-Boot and I checked it works on a useless ‘standard invocation’” > > 3. Anything else? > > For qemu_arm_spl, it *does not boot* unless the U-Boot SPL properties > are present. There is no easy way to fix this. one clean and easy way would be to upstream a Qemu change to merge a supplied overlay to the generated one. This the same idea as applying the NT_FW_COnFIG overlay in the TFA world. In both cases previous loaders do their job properly for U-Boot : setting up the stage as needed. > If we merge them into > qemu with dumpdtb, etc. we are assuming that the node we want to > update is present, so this is not really any better than having the > devicetree in U-Boot. Actually I think it is worse, since who knows > what changes might happen to the devicetree in QEMU which will stop > U-Boot from working. > > QEMU cannot make changes that don't follow the bindings. U-Boot uses > the bindings, so we are good. > > It just seems very clear to me that this approach is far superior to > U-Boot to the wonky business that we have today. > > > > > > > It is important to make sure our "develop our project" workflow is > sane > > > > and relatively pain free. But that needs to not come by making > > > > sacrifices to the "use our project" outcome. I would hope for > example > > > > that the new Pi zero platform is just dtb changes, as far as the > linux > > > > kernel is concerned which means that for rpi_arm64 (which uses run > time > > > > dtb) it also just works. And that's what we want to see. > > > > > > So long as OF_BOARD is enabled then the flow should work as you expect. > > > > Then we need to get things spun such that we can build the platforms > > where the dtb is given to us, complete and correct, at run time, to not > > require an in-tree dts that's not going to be used. Documentation > > (another area we have much improved on these past few years and for > > which I am grateful for all of the effort behind!) is how we make the > > developer use-case for those platforms better. > > I did not expect everyone to love this; this is how we got into the > mess we are in. A few people thinking it would be expedient to just do > their own thing. But I have come to this after an enormous amount of > thought and much discussion. I think sometimes people imagine that I > just throw things over the wall to get a reaction. That is not the > case. > > We need some way to put U-Boot properties in there, at least until > things change upstream and within U-Boot. That envisages tooling that > is clearly not going to be in place for the upcoming release. > > For the test, how about I create a separate qemu build (which I have > done, actually, qemu_arm_spl) and control the QEMU flags so we know it > will boot. It is for CI so we can keep it in sync and deal with any > breakages if people change things in QEMU (as above, this seems to be > a theoretical problem). > > Again, please take a deep breath and consider how much this actually > affects TF-A, QEMU, etc. I'd argue not at all. We are talking about a > build-time devicetree in the U-Boot tree. We are not talking about > disabling OF_BOARD or removing that option. > It is less about development environnement and respective CIs and more about how we want to deliver products on the market and how the supply chain is organized. U-Boot is a key component of that chain. If something is missing from the previous stages of the chain, don’t try to work around the problem in U-Boot, just propose the change/correction in the relevant project (Qemu, TFA, RPI Videocore…) or ask for help. If nothing can be resolved “the clean way” then we can hack our way out (Qemu fork you proposed). But let’s try the clean path first. > > Regards, > Simon > > [1] > http://patchwork.ozlabs.org/project/uboot/patch/20170402082520.32546-1-deymo@google.com/ > [2] https://u-boot.readthedocs.io/en/latest/board/emulation/qemu-arm.html >
On Tue, Nov 02, 2021 at 07:29:54PM -0600, Simon Glass wrote: > Hi Tom, > > On Tue, 2 Nov 2021 at 11:28, Tom Rini <trini@konsulko.com> wrote: > > > > On Tue, Nov 02, 2021 at 09:00:53AM -0600, Simon Glass wrote: > > > Hi Tom, > > > > > > On Mon, 1 Nov 2021 at 12:07, Tom Rini <trini@konsulko.com> wrote: > > > > > > > > On Mon, Nov 01, 2021 at 06:33:35PM +0100, François Ozog wrote: > > > > > Hi Simon > > > > > > > > > > Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a écrit : > > > > > > > > > > > Hi Peter, > > > > > > > > > > > > On Mon, 1 Nov 2021 at 04:48, Peter Maydell <peter.maydell@linaro.org> > > > > > > wrote: > > > > > > > > > > > > > > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: > > > > > > > > > > > > > > > > Add this file, generated from qemu, so there is a reference devicetree > > > > > > > > in the U-Boot tree. > > > > > > > > > > > > > > > > Signed-off-by: Simon Glass <sjg@chromium.org> > > > > > > > > > > > > > > Note that the dtb you get from QEMU is only guaranteed to work if: > > > > > > > 1) you run it on the exact same QEMU version you generated it with > > > > > > > 2) you pass QEMU the exact same command line arguments you used > > > > > > > when you generated it > > > > > > > > > > > > Yes, I certainly understand that. In general this is not safe, but in > > > > > > practice it works well enough for development and CI. > > > > > > > > > > You recognize that you hijack a product directory with development hack > > > > > facility. There is a test directory to keep things clear. There can be a > > > > > dev-dts or something similar for Dev time tools. > > > > > I have only seen push back on those fake dts files in the dts directory: I > > > > > guess that unless someone strongly favors a continuation of the discussion, > > > > > you may consider re-shaping the proposal to address concerns. > > > > > > > > Yes. We need to document how to make development easier. But I'm still > > > > not on board with the notion of including DTS files for platforms where > > > > the source of truth for the DTB is elsewhere. That's going to bring us > > > > a lot more pain. > > > > > > Are you talking about QEMU specifically, or Raspberry Pi? > > > > I was using two of the more common and readily available platforms where > > the source of truth for the DTS/DTB is not (and will not be) U-Boot. > > > > > How can we get this resolved? I very much want to get to just having > > > OF_SEPARATE and OF_EMBED as the only available build-time options, > > > with OF_BOARD (and perhaps OF_PASSAGE) as something we can enable for > > > runtime support. I feel that separating the build-time and run-time > > > behaviour is very important. Over time perhaps we will have some > > > success in upstreaming bindings, but for now we have what we have. > > > There is still a lot of pushback on U-Boot having things in the > > > devicetree, although I do see that softening somewhat. > > > > > > To reiterate, the uniform bit of feedback on this series has been that > > everyone else disagrees with your notion that we _must_ have a dts > > in-tree. > > [I would like everyone to take a deep breath and think about what this > actually impacts. I argue the impact outside U-Boot is approximately > zero. What are we actually discussing here?] We're discussing what the point of these files even is. And ensuring that it doesn't lead to some sort of "feature creep" or similar where they do become required to use. > A few have responded that they can just add the files. I think that is Yes, you've asked a number of people to do something, and given your position with the community they just said OK. > the case for everything except QEMU, right? I think even François > agrees with the documentation argument. There is no real burden in > adding the files so we can see what is going on, add a binman node, > SPL nodes, etc. I know François already replied, so I'm replying for myself here. What is the point of these files, if they are not going to ever be used, other than as documentation? So that people that don't have a given platform can more easily browse the device tree for it? That's a documentation fix (doc/board/... should note where to go to find it). > So I am going to stand my ground on that one. It affects: > > - highbank > - qemu-ppce500 > - rpi_4 > - xilinx_versal_virt > - octeontx > - xenguest_arm64 > - juno > > So that is just 7 boards that I want to add devicetree files for. I > think that is reasonable and not a burden on these maintainers. It effects every board where the source of truth for the DT is not the one we're embedding because the hardware doesn't ship with one on it. That's all of the QEMU targets, all of the Pi targets and a growing list of newer hardware too, due to the push for "the hardware should come with the device tree, not the linux kernel" portion of how DT has been intended to work since forever getting realized more often. > Let me deal with QEMU. > > Let's imagine that we were in the state that I am proposing here, > which we would be if I were a better devicetree maintainer for U-Boot > and had not taken my eye off the ball, basically with my review of > [1], where I should have pushed to get a response on the questions > before it was applied. That might have triggered me to think about the > implications of this at the time. > > Anyway, in the state that I am proposing, what problems would we have? > > 1. QEMU has a DT which only matches the 'standard' invocation as > documented at [2] > > 2. QEMU may get out of date if there is a new release. > > I don't think (1) is really a problem. People will have to remove > CONFIG_OF_BOARD from configs/qemu_arm_spl_defconfig (or the like) to > get into this state, and we have a message now that prints out where > the devicetree comes from ("separate" in this case): > > Core: 42 devices, 11 uclasses, devicetree: separate > > For (2), I tested QEMU 6.1.50 and the only difference from 4.2.1 (a > year old) is: > > kaslr-seed = <0x2037f53d 0x42c279e8>; > > It doesn't affect anything here. It boots the lastest image fine. > > Just for interest I went back to 2.5.0 which is nearly 6 years old! > There are a few differences like dma-coherent and gpio-keys being > added, but again it boots fine. > > So in practice that doesn't seem to be a problem from what I can tell. > > 3. Anything else? Yes, a TPM (or not) existing. > For qemu_arm_spl, it *does not boot* unless the U-Boot SPL properties > are present. There is no easy way to fix this. If we merge them into > qemu with dumpdtb, etc. we are assuming that the node we want to > update is present, so this is not really any better than having the > devicetree in U-Boot. Actually I think it is worse, since who knows > what changes might happen to the devicetree in QEMU which will stop > U-Boot from working. > > QEMU cannot make changes that don't follow the bindings. U-Boot uses > the bindings, so we are good. > > It just seems very clear to me that this approach is far superior to > U-Boot to the wonky business that we have today. We also need to be clear what the point of QEMU virtual machine support is. It's to enable testing of features that we also want to test on real hardware, to the extent possible. The follow up to that point is when we use QEMU to emulate real hardware to again test U-Boot to the extent possible. Given the list of hardware on https://qemu.readthedocs.io/en/latest/system/target-arm.html (and to be clear, I've not validated every possible board there) I would be hopeful that we can cover all of the features we need on real hardware by emulating specific targets in CI. Where the source of truth for the device tree is provided to us at run time when we start executing (so yes, the dtb that the Pi firmware assembles from files on the SD card or the one QEMU passes or the one that exists on SPI flash somewhere or ...) we must use that tree. We must not build a full separate tree because that would never be used at run time. That may mean that some features are not going to be supported right there (so yes, SPL in QEMU virtual machine on ARM) ever, or without some additional reasoning and work because it's useful to end users (figuring out a good way to generate a .dtbo so that the Pi firmware could still have a flawed but possibly better than nothing verified boot flow). > > > > It is important to make sure our "develop our project" workflow is sane > > > > and relatively pain free. But that needs to not come by making > > > > sacrifices to the "use our project" outcome. I would hope for example > > > > that the new Pi zero platform is just dtb changes, as far as the linux > > > > kernel is concerned which means that for rpi_arm64 (which uses run time > > > > dtb) it also just works. And that's what we want to see. > > > > > > So long as OF_BOARD is enabled then the flow should work as you expect. > > > > Then we need to get things spun such that we can build the platforms > > where the dtb is given to us, complete and correct, at run time, to not > > require an in-tree dts that's not going to be used. Documentation > > (another area we have much improved on these past few years and for > > which I am grateful for all of the effort behind!) is how we make the > > developer use-case for those platforms better. > > I did not expect everyone to love this; this is how we got into the > mess we are in. A few people thinking it would be expedient to just do > their own thing. But I have come to this after an enormous amount of > thought and much discussion. I think sometimes people imagine that I > just throw things over the wall to get a reaction. That is not the > case. I don't think anyone thinks you're doing this just to see what everyone else thinks. Especially since the feedback has been consistent and uniform disagreement. I also agree that what we're doing today isn't quite what I'd like to see. But that's because when the source of truth for the device tree is external to us, we are not consistent. And we didn't push hard enough earlier on to get bindings we need upstream. Or pushed back hard enough on ourselves to come up with a way to solve some of the problems without the bindings we added. > We need some way to put U-Boot properties in there, at least until > things change upstream and within U-Boot. That envisages tooling that > is clearly not going to be in place for the upcoming release. > > For the test, how about I create a separate qemu build (which I have > done, actually, qemu_arm_spl) and control the QEMU flags so we know it > will boot. It is for CI so we can keep it in sync and deal with any > breakages if people change things in QEMU (as above, this seems to be > a theoretical problem). > > Again, please take a deep breath and consider how much this actually > affects TF-A, QEMU, etc. I'd argue not at all. We are talking about a > build-time devicetree in the U-Boot tree. We are not talking about > disabling OF_BOARD or removing that option. The problem I still have here is that if the source of truth for the device tree on a platform is given to us at run time we must use it. That you've noted the QEMU tree has changed only a little bit isn't super re-assuring. And the Pi platforms show more cases where it's an active problem. And since we should be using the true device tree, not a just for reference tree, why have the copy in tree at all?
On Tue, Nov 02, 2021 at 07:32:54PM -0600, Simon Glass wrote: > Hi Tom, > > On Tue, 2 Nov 2021 at 10:57, Tom Rini <trini@konsulko.com> wrote: > > > > On Tue, Nov 02, 2021 at 08:59:45AM -0600, Simon Glass wrote: > > > Hi François, > > > > > > On Mon, 1 Nov 2021 at 11:33, François Ozog <francois.ozog@linaro.org> wrote: > > > > > > > > Hi Simon > > > > > > > > Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a écrit : > > > >> > > > >> Hi Peter, > > > >> > > > >> On Mon, 1 Nov 2021 at 04:48, Peter Maydell <peter.maydell@linaro.org> wrote: > > > >> > > > > >> > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> wrote: > > > >> > > > > > >> > > Add this file, generated from qemu, so there is a reference devicetree > > > >> > > in the U-Boot tree. > > > >> > > > > > >> > > Signed-off-by: Simon Glass <sjg@chromium.org> > > > >> > > > > >> > Note that the dtb you get from QEMU is only guaranteed to work if: > > > >> > 1) you run it on the exact same QEMU version you generated it with > > > >> > 2) you pass QEMU the exact same command line arguments you used > > > >> > when you generated it > > > >> > > > >> Yes, I certainly understand that. In general this is not safe, but in > > > >> practice it works well enough for development and CI. > > > > > > > > You recognize that you hijack a product directory with development hack facility. There is a test directory to keep things clear. There can be a dev-dts or something similar for Dev time tools. > > > > I have only seen push back on those fake dts files in the dts directory: I guess that unless someone strongly favors a continuation of the discussion, you may consider re-shaping the proposal to address concerns. > > > > > > As stated previously, I would like to have at least a sample DT > > > in-tree for all boards. I cannot see another way to get the Kconfig > > > > What's the point of having a sample when it's not going to always be > > correct or may be actively wrong and we can tell interested developers / > > users how to get the correct DTB/DTS to examine? > > > > > options in line. If we are able to put these files somewhere else in > > > the future and get them out of U-Boot, with perhaps just an overlay > > > for development purposes, I'd be keen to see it. But for now, this is > > > where we are, I believe. > > > > > > In this particular case, this is not just a dev hack. It is also for > > > CI tests which need to use a devicetree. See for example here: > > > > > > https://patchwork.ozlabs.org/project/uboot/patch/20211101011734.1614781-15-sjg@chromium.org/ > > > https://patchwork.ozlabs.org/project/uboot/patch/20211101011734.1614781-24-sjg@chromium.org/ > > > > This example would probably be better done on vexpress_ca9x4 where we do > > test in CI via QEMU but do not need to modify a device tree that is > > passed on to us, we already control the source of truth DTB in this > > case. > > But that board: > > - uses OF_EMBED, which it should not > - does not use SPL, which I need Check out the other hardware then that we emulate today, and or maybe something off of https://qemu.readthedocs.io/en/latest/system/target-arm.html that we could add. My point is that by picking the QEMU targets for where to test this feature you've gone with "I've introduced this feature so now I need to introduce this other change I've been arguing for too" in an artificial manner as it would only be used like that for testing.
On Wed, Nov 03, 2021 at 06:29:20AM +0100, François Ozog wrote: [snip] > > 3. Anything else? > > > > For qemu_arm_spl, it *does not boot* unless the U-Boot SPL properties > > are present. There is no easy way to fix this. > > one clean and easy way would be to upstream a Qemu change to merge a > supplied overlay to the generated one. This the same idea as applying the > NT_FW_COnFIG overlay in the TFA world. In both cases previous loaders do > their job properly for U-Boot : setting up the stage as needed. For the record, I believe Simon did propose this and the QEMU response was that no, you should dumpdtb, combine externally and pass that directly.
Hi Simon, and team On Wed, 3 Nov 2021 at 06:29, François Ozog <francois.ozog@linaro.org> wrote: > Hi Simon > > Le mer. 3 nov. 2021 à 02:30, Simon Glass <sjg@chromium.org> a écrit : > >> Hi Tom, >> >> On Tue, 2 Nov 2021 at 11:28, Tom Rini <trini@konsulko.com> wrote: >> > >> > On Tue, Nov 02, 2021 at 09:00:53AM -0600, Simon Glass wrote: >> > > Hi Tom, >> > > >> > > On Mon, 1 Nov 2021 at 12:07, Tom Rini <trini@konsulko.com> wrote: >> > > > >> > > > On Mon, Nov 01, 2021 at 06:33:35PM +0100, François Ozog wrote: >> > > > > Hi Simon >> > > > > >> > > > > Le lun. 1 nov. 2021 à 17:58, Simon Glass <sjg@chromium.org> a >> écrit : >> > > > > >> > > > > > Hi Peter, >> > > > > > >> > > > > > On Mon, 1 Nov 2021 at 04:48, Peter Maydell < >> peter.maydell@linaro.org> >> > > > > > wrote: >> > > > > > > >> > > > > > > On Tue, 26 Oct 2021 at 01:33, Simon Glass <sjg@chromium.org> >> wrote: >> > > > > > > > >> > > > > > > > Add this file, generated from qemu, so there is a reference >> devicetree >> > > > > > > > in the U-Boot tree. >> > > > > > > > >> > > > > > > > Signed-off-by: Simon Glass <sjg@chromium.org> >> > > > > > > >> > > > > > > Note that the dtb you get from QEMU is only guaranteed to >> work if: >> > > > > > > 1) you run it on the exact same QEMU version you generated >> it with >> > > > > > > 2) you pass QEMU the exact same command line arguments you >> used >> > > > > > > when you generated it >> > > > > > >> > > > > > Yes, I certainly understand that. In general this is not safe, >> but in >> > > > > > practice it works well enough for development and CI. >> > > > > >> > > > > You recognize that you hijack a product directory with >> development hack >> > > > > facility. There is a test directory to keep things clear. There >> can be a >> > > > > dev-dts or something similar for Dev time tools. >> > > > > I have only seen push back on those fake dts files in the dts >> directory: I >> > > > > guess that unless someone strongly favors a continuation of the >> discussion, >> > > > > you may consider re-shaping the proposal to address concerns. >> > > > >> > > > Yes. We need to document how to make development easier. But I'm >> still >> > > > not on board with the notion of including DTS files for platforms >> where >> > > > the source of truth for the DTB is elsewhere. That's going to >> bring us >> > > > a lot more pain. >> > > >> > > Are you talking about QEMU specifically, or Raspberry Pi? >> > >> > I was using two of the more common and readily available platforms where >> > the source of truth for the DTS/DTB is not (and will not be) U-Boot. >> > >> > > How can we get this resolved? I very much want to get to just having >> > > OF_SEPARATE and OF_EMBED as the only available build-time options, >> > > with OF_BOARD (and perhaps OF_PASSAGE) as something we can enable for >> > > runtime support. I feel that separating the build-time and run-time >> > > behaviour is very important. Over time perhaps we will have some >> > > success in upstreaming bindings, but for now we have what we have. >> > > There is still a lot of pushback on U-Boot having things in the >> > > devicetree, although I do see that softening somewhat. >> > >> > >> > To reiterate, the uniform bit of feedback on this series has been that >> > everyone else disagrees with your notion that we _must_ have a dts >> > in-tree. >> >> [I would like everyone to take a deep breath and think about what this >> actually impacts. I argue the impact outside U-Boot is approximately >> zero. What are we actually discussing here?] >> >> A few have responded that they can just add the files. I think that is >> the case for everything except QEMU, right? I think even François >> agrees with the documentation argument. > > I do providing that the sample goes into documentation, not actionable as > a build artifact in the dts directory. > >> There is no real burden in >> adding the files so we can see what is going on, add a binman node, >> SPL nodes, etc. >> >> So I am going to stand my ground on that one. It affects: >> >> - highbank >> - qemu-ppce500 >> - rpi_4 >> - xilinx_versal_virt >> - octeontx >> - xenguest_arm64 >> - juno >> >> So that is just 7 boards that I want to add devicetree files for. I >> think that is reasonable and not a burden on these maintainers. >> >> Let me deal with QEMU. >> >> Let's imagine that we were in the state that I am proposing here, >> which we would be if I were a better devicetree maintainer for U-Boot >> and had not taken my eye off the ball, basically with my review of >> [1], where I should have pushed to get a response on the questions >> before it was applied. That might have triggered me to think about the >> implications of this at the time. >> >> Anyway, in the state that I am proposing, what problems would we have? >> >> 1. QEMU has a DT which only matches the 'standard' invocation as >> documented at [2] > > >> >> 2. QEMU may get out of date if there is a new release. >> >> I don't think (1) is really a problem. People will have to remove >> CONFIG_OF_BOARD from configs/qemu_arm_spl_defconfig (or the like) to >> get into this state, and we have a message now that prints out where >> the devicetree comes from ("separate" in this case): >> >> Core: 42 devices, 11 uclasses, devicetree: separate >> >> For (2), I tested QEMU 6.1.50 and the only difference from 4.2.1 (a >> year old) is: >> >> kaslr-seed = <0x2037f53d 0x42c279e8>; >> >> It doesn't affect anything here. It boots the lastest image fine. >> >> Just for interest I went back to 2.5.0 which is nearly 6 years old! >> There are a few differences like dma-coherent and gpio-keys being >> added, but again it boots fine. >> >> So in practice that doesn't seem to be a problem from what I can tell. >> > You are essentially saying “I don’t care about the system design, this DTS > simplifies my development work for U-Boot and I checked it works on a > useless ‘standard invocation’” > >> >> 3. Anything else? >> >> For qemu_arm_spl, it *does not boot* unless the U-Boot SPL properties >> are present. There is no easy way to fix this. > > one clean and easy way would be to upstream a Qemu change to merge a > supplied overlay to the generated one. This the same idea as applying the > NT_FW_COnFIG overlay in the TFA world. In both cases previous loaders do > their job properly for U-Boot : setting up the stage as needed. > I was pointed to your proposal in Qemu mailing list and added my support to it. I could not comment on the exact details of the proposal, but commented on the fact that merging a DT fragment provided to Qemu at runtime makes sense and has some precedent in TFA. > If we merge them into >> qemu with dumpdtb, etc. we are assuming that the node we want to >> update is present, so this is not really any better than having the >> devicetree in U-Boot. Actually I think it is worse, since who knows >> what changes might happen to the devicetree in QEMU which will stop >> U-Boot from working. >> >> QEMU cannot make changes that don't follow the bindings. U-Boot uses >> the bindings, so we are good. >> >> It just seems very clear to me that this approach is far superior to >> U-Boot to the wonky business that we have today. >> >> > >> > > > It is important to make sure our "develop our project" workflow is >> sane >> > > > and relatively pain free. But that needs to not come by making >> > > > sacrifices to the "use our project" outcome. I would hope for >> example >> > > > that the new Pi zero platform is just dtb changes, as far as the >> linux >> > > > kernel is concerned which means that for rpi_arm64 (which uses run >> time >> > > > dtb) it also just works. And that's what we want to see. >> > > >> > > So long as OF_BOARD is enabled then the flow should work as you >> expect. >> > >> > Then we need to get things spun such that we can build the platforms >> > where the dtb is given to us, complete and correct, at run time, to not >> > require an in-tree dts that's not going to be used. Documentation >> > (another area we have much improved on these past few years and for >> > which I am grateful for all of the effort behind!) is how we make the >> > developer use-case for those platforms better. >> >> I did not expect everyone to love this; this is how we got into the >> mess we are in. A few people thinking it would be expedient to just do >> their own thing. But I have come to this after an enormous amount of >> thought and much discussion. I think sometimes people imagine that I >> just throw things over the wall to get a reaction. That is not the >> case. >> >> We need some way to put U-Boot properties in there, at least until >> things change upstream and within U-Boot. That envisages tooling that >> is clearly not going to be in place for the upcoming release. >> >> For the test, how about I create a separate qemu build (which I have >> done, actually, qemu_arm_spl) and control the QEMU flags so we know it >> will boot. It is for CI so we can keep it in sync and deal with any >> breakages if people change things in QEMU (as above, this seems to be >> a theoretical problem). >> >> Again, please take a deep breath and consider how much this actually >> affects TF-A, QEMU, etc. I'd argue not at all. We are talking about a >> build-time devicetree in the U-Boot tree. We are not talking about >> disabling OF_BOARD or removing that option. >> > It is less about development environnement and respective CIs and more > about how we want to deliver products on the market and how the supply > chain is organized. U-Boot is a key component of that chain. If something > is missing from the previous stages of the chain, don’t try to work around > the problem in U-Boot, just propose the change/correction in the relevant > project (Qemu, TFA, RPI Videocore…) or ask for help. If nothing can be > resolved “the clean way” then we can hack our way out (Qemu fork you > proposed). But let’s try the clean path first. > >> >> Regards, >> Simon >> >> [1] >> http://patchwork.ozlabs.org/project/uboot/patch/20170402082520.32546-1-deymo@google.com/ >> [2] https://u-boot.readthedocs.io/en/latest/board/emulation/qemu-arm.html >> > -- > François-Frédéric Ozog | *Director Business Development* > T: +33.67221.6485 > francois.ozog@linaro.org | Skype: ffozog > >
On Wed, 3 Nov 2021 at 14:41, Tom Rini <trini@konsulko.com> wrote: > > On Wed, Nov 03, 2021 at 06:29:20AM +0100, François Ozog wrote: > [snip] > > > 3. Anything else? > > > > > > For qemu_arm_spl, it *does not boot* unless the U-Boot SPL properties > > > are present. There is no easy way to fix this. > > > > one clean and easy way would be to upstream a Qemu change to merge a > > supplied overlay to the generated one. This the same idea as applying the > > NT_FW_COnFIG overlay in the TFA world. In both cases previous loaders do > > their job properly for U-Boot : setting up the stage as needed. > > For the record, I believe Simon did propose this and the QEMU response > was that no, you should dumpdtb, combine externally and pass that > directly. Well, our recommendation really was that the ideal thing would be "you take the dtb that QEMU passes you at runtime, and at runtime combine that with whatever extra information you want". The dumpdtb option is primarily intended as a debug feature, so you can have a look at the dtb QEMU created to see why your OS isn't booting; although you can script stuff up that does a dumpdtb-modify-pass-to-QEMU that is pretty clunky given the need to invoke QEMU twice with matching arguments both times. -- PMM
hi Peter Le jeu. 4 nov. 2021 à 12:09, Peter Maydell <peter.maydell@linaro.org> a écrit : > On Wed, 3 Nov 2021 at 14:41, Tom Rini <trini@konsulko.com> wrote: > > > > On Wed, Nov 03, 2021 at 06:29:20AM +0100, François Ozog wrote: > > [snip] > > > > 3. Anything else? > > > > > > > > For qemu_arm_spl, it *does not boot* unless the U-Boot SPL properties > > > > are present. There is no easy way to fix this. > > > > > > one clean and easy way would be to upstream a Qemu change to merge a > > > supplied overlay to the generated one. This the same idea as applying > the > > > NT_FW_COnFIG overlay in the TFA world. In both cases previous loaders > do > > > their job properly for U-Boot : setting up the stage as needed. > > > > For the record, I believe Simon did propose this and the QEMU response > > was that no, you should dumpdtb, combine externally and pass that > > directly. > > Well, our recommendation really was that the ideal thing would > be "you take the dtb that QEMU passes you at runtime, and at > runtime combine that with whatever extra information you want". That looks just reasonable this way. Runtime merging may need to be done before control is actually transferred. We have that problem on real board where we need to inject a TPM device for measured boot and it is not énumerable and pluggable. With TFA we have the option to add the TPM description in the NT_FW_CONFIG and merge it at run time. So we need a « -mergedtb » option for Qemu to have the same capability. This would merge the QEMU generated one with the command line provided. > > The dumpdtb option is primarily intended as a debug feature, > so you can have a look at the dtb QEMU created to see why your > OS isn't booting; although you can script stuff up that does > a dumpdtb-modify-pass-to-QEMU that is pretty clunky given the > need to invoke QEMU twice with matching arguments both times. > > -- PMM >
On Thu, 4 Nov 2021 at 11:22, François Ozog <francois.ozog@linaro.org> wrote: > Le jeu. 4 nov. 2021 à 12:09, Peter Maydell <peter.maydell@linaro.org> a écrit : >> >> Well, our recommendation really was that the ideal thing would >> be "you take the dtb that QEMU passes you at runtime, and at >> runtime combine that with whatever extra information you want". > > That looks just reasonable this way. > So we need a « -mergedtb » option for Qemu to have the same > capability. This would merge the QEMU generated one with the > command line provided. No, I mean that the guest, ie u-boot, should do the merging, not QEMU. -- PMM
Hi Peter Le jeu. 4 nov. 2021 à 12:41, Peter Maydell <peter.maydell@linaro.org> a écrit : > On Thu, 4 Nov 2021 at 11:22, François Ozog <francois.ozog@linaro.org> > wrote: > > Le jeu. 4 nov. 2021 à 12:09, Peter Maydell <peter.maydell@linaro.org> a > écrit : > >> > >> Well, our recommendation really was that the ideal thing would > >> be "you take the dtb that QEMU passes you at runtime, and at > >> runtime combine that with whatever extra information you want". > > > > That looks just reasonable this way. > > > So we need a « -mergedtb » option for Qemu to have the same > > capability. This would merge the QEMU generated one with the > > command line provided. > > No, I mean that the guest, ie u-boot, should do the merging, > not QEMU. for most of the cases it works. But, as I tried to explain some cases need earlier merging hence trying to get QEMU do the same thing as TFA as « prior loaders » in the boot chain. Worst case we can have the behavior by booting TFA then U-Boot then Linux under QEMU, but the best would be to get the facility directly when TFA is not on the path of the boot like with the VBE boot flow. > > > -- PMM >
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile index 7ab8b145f3f..e70293bb849 100644 --- a/arch/arm/dts/Makefile +++ b/arch/arm/dts/Makefile @@ -1153,7 +1153,7 @@ dtb-$(CONFIG_TARGET_IMX8MM_CL_IOT_GATE_OPTEE) += imx8mm-cl-iot-gate-optee.dtb dtb-$(CONFIG_TARGET_EA_LPC3250DEVKITV2) += lpc3250-ea3250.dtb -dtb-$(CONFIG_ARCH_QEMU) += qemu-arm.dtb +dtb-$(CONFIG_ARCH_QEMU) += qemu-arm.dtb qemu-arm64.dtb targets += $(dtb-y) diff --git a/arch/arm/dts/qemu-arm64.dts b/arch/arm/dts/qemu-arm64.dts new file mode 100644 index 00000000000..7590e49cc84 --- /dev/null +++ b/arch/arm/dts/qemu-arm64.dts @@ -0,0 +1,381 @@ +// SPDX-License-Identifier: GPL-2.0+ OR MIT +/* + * Sample device tree for qemu_arm64 + + * Copyright 2021 Google LLC + */ + +/dts-v1/; + +/ { + interrupt-parent = <0x8001>; + #size-cells = <0x02>; + #address-cells = <0x02>; + compatible = "linux,dummy-virt"; + + psci { + migrate = <0xc4000005>; + cpu_on = <0xc4000003>; + cpu_off = <0x84000002>; + cpu_suspend = <0xc4000001>; + method = "hvc"; + compatible = "arm,psci-0.2\0arm,psci"; + }; + + memory@40000000 { + reg = <0x00 0x40000000 0x00 0x8000000>; + device_type = "memory"; + }; + + platform@c000000 { + interrupt-parent = <0x8001>; + ranges = <0x00 0x00 0xc000000 0x2000000>; + #address-cells = <0x01>; + #size-cells = <0x01>; + compatible = "qemu,platform\0simple-bus"; + }; + + fw-cfg@9020000 { + dma-coherent; + reg = <0x00 0x9020000 0x00 0x18>; + compatible = "qemu,fw-cfg-mmio"; + }; + + virtio_mmio@a000000 { + dma-coherent; + interrupts = <0x00 0x10 0x01>; + reg = <0x00 0xa000000 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a000200 { + dma-coherent; + interrupts = <0x00 0x11 0x01>; + reg = <0x00 0xa000200 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a000400 { + dma-coherent; + interrupts = <0x00 0x12 0x01>; + reg = <0x00 0xa000400 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a000600 { + dma-coherent; + interrupts = <0x00 0x13 0x01>; + reg = <0x00 0xa000600 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a000800 { + dma-coherent; + interrupts = <0x00 0x14 0x01>; + reg = <0x00 0xa000800 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a000a00 { + dma-coherent; + interrupts = <0x00 0x15 0x01>; + reg = <0x00 0xa000a00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a000c00 { + dma-coherent; + interrupts = <0x00 0x16 0x01>; + reg = <0x00 0xa000c00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a000e00 { + dma-coherent; + interrupts = <0x00 0x17 0x01>; + reg = <0x00 0xa000e00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a001000 { + dma-coherent; + interrupts = <0x00 0x18 0x01>; + reg = <0x00 0xa001000 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a001200 { + dma-coherent; + interrupts = <0x00 0x19 0x01>; + reg = <0x00 0xa001200 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a001400 { + dma-coherent; + interrupts = <0x00 0x1a 0x01>; + reg = <0x00 0xa001400 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a001600 { + dma-coherent; + interrupts = <0x00 0x1b 0x01>; + reg = <0x00 0xa001600 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a001800 { + dma-coherent; + interrupts = <0x00 0x1c 0x01>; + reg = <0x00 0xa001800 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a001a00 { + dma-coherent; + interrupts = <0x00 0x1d 0x01>; + reg = <0x00 0xa001a00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a001c00 { + dma-coherent; + interrupts = <0x00 0x1e 0x01>; + reg = <0x00 0xa001c00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a001e00 { + dma-coherent; + interrupts = <0x00 0x1f 0x01>; + reg = <0x00 0xa001e00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a002000 { + dma-coherent; + interrupts = <0x00 0x20 0x01>; + reg = <0x00 0xa002000 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a002200 { + dma-coherent; + interrupts = <0x00 0x21 0x01>; + reg = <0x00 0xa002200 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a002400 { + dma-coherent; + interrupts = <0x00 0x22 0x01>; + reg = <0x00 0xa002400 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a002600 { + dma-coherent; + interrupts = <0x00 0x23 0x01>; + reg = <0x00 0xa002600 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a002800 { + dma-coherent; + interrupts = <0x00 0x24 0x01>; + reg = <0x00 0xa002800 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a002a00 { + dma-coherent; + interrupts = <0x00 0x25 0x01>; + reg = <0x00 0xa002a00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a002c00 { + dma-coherent; + interrupts = <0x00 0x26 0x01>; + reg = <0x00 0xa002c00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a002e00 { + dma-coherent; + interrupts = <0x00 0x27 0x01>; + reg = <0x00 0xa002e00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a003000 { + dma-coherent; + interrupts = <0x00 0x28 0x01>; + reg = <0x00 0xa003000 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a003200 { + dma-coherent; + interrupts = <0x00 0x29 0x01>; + reg = <0x00 0xa003200 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a003400 { + dma-coherent; + interrupts = <0x00 0x2a 0x01>; + reg = <0x00 0xa003400 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a003600 { + dma-coherent; + interrupts = <0x00 0x2b 0x01>; + reg = <0x00 0xa003600 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a003800 { + dma-coherent; + interrupts = <0x00 0x2c 0x01>; + reg = <0x00 0xa003800 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a003a00 { + dma-coherent; + interrupts = <0x00 0x2d 0x01>; + reg = <0x00 0xa003a00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a003c00 { + dma-coherent; + interrupts = <0x00 0x2e 0x01>; + reg = <0x00 0xa003c00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + virtio_mmio@a003e00 { + dma-coherent; + interrupts = <0x00 0x2f 0x01>; + reg = <0x00 0xa003e00 0x00 0x200>; + compatible = "virtio,mmio"; + }; + + pcie@10000000 { + interrupt-map-mask = <0x1800 0x00 0x00 0x07>; + interrupt-map = <0x00 0x00 0x00 0x01 0x8001 0x00 0x00 0x00 + 0x03 0x04 0x00 0x00 0x00 0x02 0x8001 0x00 + 0x00 0x00 0x04 0x04 0x00 0x00 0x00 0x03 + 0x8001 0x00 0x00 0x00 0x05 0x04 0x00 0x00 + 0x00 0x04 0x8001 0x00 0x00 0x00 0x06 0x04 + 0x800 0x00 0x00 0x01 0x8001 0x00 0x00 0x00 + 0x04 0x04 0x800 0x00 0x00 0x02 0x8001 0x00 + 0x00 0x00 0x05 0x04 0x800 0x00 0x00 0x03 + 0x8001 0x00 0x00 0x00 0x06 0x04 0x800 0x00 + 0x00 0x04 0x8001 0x00 0x00 0x00 0x03 0x04 + 0x1000 0x00 0x00 0x01 0x8001 0x00 0x00 0x00 + 0x05 0x04 0x1000 0x00 0x00 0x02 0x8001 0x00 + 0x00 0x00 0x06 0x04 0x1000 0x00 0x00 0x03 + 0x8001 0x00 0x00 0x00 0x03 0x04 0x1000 0x00 + 0x00 0x04 0x8001 0x00 0x00 0x00 0x04 0x04 + 0x1800 0x00 0x00 0x01 0x8001 0x00 0x00 0x00 + 0x06 0x04 0x1800 0x00 0x00 0x02 0x8001 0x00 + 0x00 0x00 0x03 0x04 0x1800 0x00 0x00 0x03 + 0x8001 0x00 0x00 0x00 0x04 0x04 0x1800 0x00 + 0x00 0x04 0x8001 0x00 0x00 0x00 0x05 0x04>; + #interrupt-cells = <0x01>; + ranges = <0x1000000 0x00 0x00 0x00 + 0x3eff0000 0x00 0x10000 0x2000000 + 0x00 0x10000000 0x00 0x10000000 + 0x00 0x2eff0000 0x3000000 0x80 + 0x00 0x80 0x00 0x80 + 0x00>; + reg = <0x40 0x10000000 0x00 0x10000000>; + msi-parent = <0x8002>; + dma-coherent; + bus-range = <0x00 0xff>; + linux,pci-domain = <0x00>; + #size-cells = <0x02>; + #address-cells = <0x03>; + device_type = "pci"; + compatible = "pci-host-ecam-generic"; + }; + + pl031@9010000 { + clock-names = "apb_pclk"; + clocks = <0x8000>; + interrupts = <0x00 0x02 0x04>; + reg = <0x00 0x9010000 0x00 0x1000>; + compatible = "arm,pl031\0arm,primecell"; + }; + + pl011@9000000 { + clock-names = "uartclk\0apb_pclk"; + clocks = <0x8000 0x8000>; + interrupts = <0x00 0x01 0x04>; + reg = <0x00 0x9000000 0x00 0x1000>; + compatible = "arm,pl011\0arm,primecell"; + }; + + pmu { + interrupts = <0x01 0x07 0x104>; + compatible = "arm,armv8-pmuv3"; + }; + + intc@8000000 { + phandle = <0x8001>; + reg = <0x00 0x8000000 0x00 0x10000 0x00 0x8010000 0x00 0x10000>; + compatible = "arm,cortex-a15-gic"; + ranges; + #size-cells = <0x02>; + #address-cells = <0x02>; + interrupt-controller; + #interrupt-cells = <0x03>; + + v2m@8020000 { + phandle = <0x8002>; + reg = <0x00 0x8020000 0x00 0x1000>; + msi-controller; + compatible = "arm,gic-v2m-frame"; + }; + }; + + flash@0 { + bank-width = <0x04>; + reg = <0x00 0x00 0x00 0x4000000 0x00 0x4000000 0x00 0x4000000>; + compatible = "cfi-flash"; + }; + + cpus { + #size-cells = <0x00>; + #address-cells = <0x01>; + + cpu@0 { + reg = <0x00>; + compatible = "arm,cortex-a57"; + device_type = "cpu"; + }; + }; + + timer { + interrupts = <0x01 0x0d 0x104 0x01 0x0e 0x104 0x01 0x0b 0x104 0x01 0x0a 0x104>; + always-on; + compatible = "arm,armv8-timer\0arm,armv7-timer"; + }; + + apb-pclk { + phandle = <0x8000>; + clock-output-names = "clk24mhz"; + clock-frequency = <0x16e3600>; + #clock-cells = <0x00>; + compatible = "fixed-clock"; + }; + + chosen { + stdout-path = "/pl011@9000000"; + }; +}; diff --git a/configs/qemu_arm64_defconfig b/configs/qemu_arm64_defconfig index cf5a03e8a2f..e51ce5c799f 100644 --- a/configs/qemu_arm64_defconfig +++ b/configs/qemu_arm64_defconfig @@ -5,6 +5,7 @@ CONFIG_NR_DRAM_BANKS=1 CONFIG_ENV_SIZE=0x40000 CONFIG_ENV_SECT_SIZE=0x40000 CONFIG_SYS_MALLOC_LEN=0x1000000 +CONFIG_DEFAULT_DEVICE_TREE="qemu-arm64" CONFIG_AHCI=y CONFIG_DISTRO_DEFAULTS=y CONFIG_SYS_LOAD_ADDR=0x40200000
Add this file, generated from qemu, so there is a reference devicetree in the U-Boot tree. Signed-off-by: Simon Glass <sjg@chromium.org> --- (no changes since v1) arch/arm/dts/Makefile | 2 +- arch/arm/dts/qemu-arm64.dts | 381 +++++++++++++++++++++++++++++++++++ configs/qemu_arm64_defconfig | 1 + 3 files changed, 383 insertions(+), 1 deletion(-) create mode 100644 arch/arm/dts/qemu-arm64.dts