Hi Raymond, On Fri, 28 Mar 2025 at 08:38, Raymond Mao <raymond....@linaro.org> wrote: > > Hi Simon, > > On Fri, 28 Mar 2025 at 10:26, Simon Glass <s...@chromium.org> wrote: > > > > Hi Raymond, > > > > On Fri, 28 Mar 2025 at 08:17, Raymond Mao <raymond....@linaro.org> wrote: > > > > > > Hi Simon, > > > > > > On Fri, 28 Mar 2025 at 07:34, Simon Glass <s...@chromium.org> wrote: > > > > > > > > Hi Raymond, > > > > > > > > On Thu, 27 Mar 2025 at 17:13, Raymond Mao <raymond....@linaro.org> > > > > wrote: > > > > > > > > > > When a bloblist is valid and contains fdt, it explicitly means > > > > > a previous boot stage is passing transfer list compliant with > > > > > Firmware Handoff specification, thus the fdt from bloblist should > > > > > not be overridden with the ones from board or env variables. > > > > > > > > Why is that? The board can choose to override it, if it wishes, but in > > > > general, if gd->fdt_blob is already set up, it should return -EEXIST > > > > from board_fdt_blob_setup(). > > > > > > > First, if a board is running in a "stand-alone" mode, there should not > > > be a transfer list passed from the previous boot stage. > > > Secondly, overriding the transfer list with the env variables does not > > > make sense, since booti, bootm and bootefi are actually using the env > > > variables to get the fdt when launching to the kernel. > > > We need to do the opposite way - override the env variable with the > > > one pointing to the bloblist fdt (See my patch [2/2]), then all boot > > > commands can work with the transfer list. > > > > OK, but now we are going back to the OF_BLOBLIST thing that I did 18 > > months ago and ended up being the major reason I had to create my own > > U-Boot tree just to get my boards working. > > > > Anyway, Tom has agreed to let me maintain bloblist (and maybe fdt?) > > again, so I am going to send a series to 'clean this up' as Ilias > > would say. Let's see if that passes muster, because I do agree with > > you that if the devicetree is in the bloblist, it should be > > definitive. > > > > Re your second point, do you know why we have fdt_addr? Is it just for > > the distro scripts? I'm wondering if we could restrict the use of > > fdt_addr to just the places that actually need to use environment > > variables. > > > > I understand that there is a clean-up plan from you, so this time I am > just trying to minimize the changes (as you can see, just a few lines) > to make the transfer list work again. > I am also working on the OP-TEE repo project to enable qemu v8 build > with transfer list enabled, so users can just use a single command to > test the Firmware Handoff feature from TF-A to kernel. > But since 70fe23859437, it is broken in U-Boot due to the overriding > of the fdt, I made this hotfix in order to let us have the feature > work again before the upcoming release.
Yes I looked up that commit but it was over a year ago so I assumed that something else was going on. Re your project, it would be good to get that running in CI. My old standard passage stuff had such a test and I think it was pretty easy within U-Boot. Anyway, this patch doesn't make things any worse. Reviewed-by: Simon Glass <s...@chromium.org> Regards, SImon
