Hi Sean, On Fri, 11 Aug 2023 at 11:14, Sean Edmond <seanedm...@linux.microsoft.com> wrote: > > > On 2023-08-09 6:49 p.m., Simon Glass wrote: > > Hi Sean, > > > > On Wed, 9 Aug 2023 at 16:35, Sean Edmond <seanedm...@linux.microsoft.com> wrote: > >> > >> On 2023-08-08 7:03 p.m., Simon Glass wrote: > >>> Hi, > >>> > >>> On Fri, 4 Aug 2023 at 17:34, <seanedm...@linux.microsoft.com> wrote: > >>>> From: Dhananjay Phadke <dpha...@linux.microsoft.com> > >>>> > >>>> fdt_fixup_kaslr_seed() will update given FDT with random seed value. > >>>> Source for random seed can be TPM or RNG driver in u-boot or sec > >>>> firmware (ARM). > >>>> > >>>> Signed-off-by: Dhananjay Phadke <dpha...@linux.microsoft.com> > >>>> --- > >>>> arch/arm/cpu/armv8/sec_firmware.c | 32 +++++++------------------------ > >>>> common/fdt_support.c | 31 ++++++++++++++++++++++++++++++ > >>>> include/fdt_support.h | 3 +++ > >>>> 3 files changed, 41 insertions(+), 25 deletions(-) > >>> We need to find a way to use the ofnode API here. > >>> > >>>> diff --git a/arch/arm/cpu/armv8/sec_firmware.c b/arch/arm/cpu/armv8/sec_firmware.c > >>>> index c0e8726346..84ba49924e 100644 > >>>> --- a/arch/arm/cpu/armv8/sec_firmware.c > >>>> +++ b/arch/arm/cpu/armv8/sec_firmware.c > >>>> @@ -411,46 +411,28 @@ int sec_firmware_init(const void *sec_firmware_img, > >>>> /* > >>>> * fdt_fix_kaslr - Add kalsr-seed node in Device tree > >>>> * @fdt: Device tree > >>>> - * @eret: 0 in case of error, 1 for success > >>>> + * @eret: 0 for success > >>>> */ > >>>> int fdt_fixup_kaslr(void *fdt) > >>> You could pass an oftree to this function, e.g. obtained with: > >>> > >>> oftree_from_fdt(fdt) > >> The common API I added is fdt_fixup_kaslr_seed(), which was added to > >> "common/fdt_support.c". > >> > >> There are 3 callers: > >> sec_firmware_init()->fdt_fixup_kaslr_seed() > >> do_kaslr_seed()->fdt_fixup_kaslr_seed() > >> image_setup_libfdt()->fdt_tpm_kaslr_seed->fdt_fixup_kaslr_seed() > >> > >> I think the ask is to create a common API that uses the ofnode API. So, > >> instead of fdt_fixup_kaslr_seed() I can create > >> ofnode_fixup_kaslr_seed()? Where should it live? > > If you like you could add common/ofnode_support.c ? > > > > But it is OK to have it in the same file, I think. > > > >> Are you also wanting > >> the callers (eg. fdt_tpm_kaslr_seed, fdt_fixup_kaslr) to take oftree as > >> input too? > > So far as you can go, yes. Also you may want to pass an ofnode (the > > root node) so that things can deal with adding their stuff to any > > node. > > > > Regards, > > Simon > > > I re-worked the API to use the ofnode API and tested it on our board. I > was required to explicitly enable CONFIG_OFNODE_MULTI_TREE in order for > it to work. > > I have concerns this will create a breaking change for users of the > kaslr fdt touch up. In our case, if CONFIG_OFNODE_MULTI_TREE isn't set, > the control FDT gets touched up, not the kernel FDT as required. > Everything runs to completion, but "/proc/device-tree/chosen/kaslr-seed" > isn't present after boot. > > Am I missing something? Perhaps there's a way to modify the default > value for CONFIG_OFNODE_MULTI_TREE to ensure this works out-of-the-box? >
Yes, perhaps we should enable this when fixups are used? Is there a way to tell? Also, we should make it return an error when attempting to use a tree without that option enabled. I would expect oftree_ensure() to provide that? Regards, Simon
