On Fri, Jan 16, 2026 at 08:34:33AM +0100, Neil Armstrong wrote: > On 1/16/26 07:57, Sumit Garg wrote: > > On Thu, Jan 15, 2026 at 02:35:23PM +0100, Neil Armstrong wrote: > > > On 1/15/26 14:27, Sumit Garg wrote: > > > > On Thu, Jan 15, 2026 at 02:03:29PM +0100, Neil Armstrong wrote: > > > > > On 1/15/26 13:25, Sumit Garg wrote: > > > > > > + Jens (OP-TEE driver author in U-Boot) > > > > > > > > > > > > On Thu, Jan 15, 2026 at 11:49:49AM +0100, [email protected] > > > > > > wrote: > > > > > > > On 1/15/26 07:10, Sumit Garg wrote: > > > > > > > > On Wed, Jan 14, 2026 at 03:56:02PM +0100, Casey Connolly wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > On 09/01/2026 12:02, Sumit Garg wrote: > > > > > > > > > > On Thu, Jan 08, 2026 at 05:41:42PM +0100, Casey Connolly > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On 29/12/2025 12:43, Sumit Garg wrote: > > > > > > > > > > > > From: Sumit Garg <[email protected]> > > > > > > > > > > > > > > > > > > > > > > > > Recently upstream TF-A/OP-TEE has started gaining > > > > > > > > > > > > support for Qcom > > > > > > > > > > > > platforms. RB3Gen2 being the first one and more to > > > > > > > > > > > > come. U-Boot in > > > > > > > > > > > > corresponding boot flow is packaged as a position > > > > > > > > > > > > independent executable. > > > > > > > > > > > > > > > > > > > > > > > > So, lets add a generic U-Boot defconfig for Qcom > > > > > > > > > > > > platforms to support > > > > > > > > > > > > TF-A/OP-TEE based TrustZone stack. Build command: > > > > > > > > > > > > > > > > > > > > > > > > $ make qcom_tfa_optee_defconfig > > > > > > > > > > > > $ make -j`nproc` DEVICE_TREE=qcom/qcs6490-rb3gen2 > > > > > > > > > > > > > > > > > > > > > > This would be better suited as a config fragment rather > > > > > > > > > > > than a new > > > > > > > > > > > defconfig imo. > > > > > > > > > > > > > > > > > > > > That's fine with me to add it as a config fragment. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > But more importantly, enabling OPTEE support in U-Boot > > > > > > > > > > > doesn't imply > > > > > > > > > > > that it will be used, just that it's supported. > > > > > > > > > > > > > > > > > > > > There are real use-cases of OP-TEE in U-Boot for Qcom > > > > > > > > > > platforms like > > > > > > > > > > secure EFI variables based on OP-TEE secure storage. Have a > > > > > > > > > > look here [1]. > > > > > > > > > > > > > > > > > > > > And sure there will be more such use-cases like fTPM, KASLR > > > > > > > > > > etc. can be > > > > > > > > > > supported based on OP-TEE. > > > > > > > > > > > > > > > > > > I was referring literally to the fact that CONFIG_OPTEE being > > > > > > > > > enabled > > > > > > > > > doesn't imply that OP-TEE is running, it's faulty logic to > > > > > > > > > assume that's > > > > > > > > > the case and add nodes to the DT. > > > > > > > > > > > > > > > > I don't disagree here as having a runtime check is always a > > > > > > > > better > > > > > > > > choice then a compile time config option. However, there isn't > > > > > > > > a common > > > > > > > > info method from properietary firmware that says if QTEE is > > > > > > > > running > > > > > > > > instead of OP-TEE. > > > > > > > > > > > > > > > > > > > > > > > > > > I just checked and there is an SMC call that tells you the > > > > > > > > > UUID for the > > > > > > > > > trusted OS, referred to as OPTEE_SMC_CALL_GET_OS_UUID in > > > > > > > > > U-Boot and > > > > > > > > > OPTEE_ABI_CALL_GET_OS_UUID in OP-TEE. Presumably this > > > > > > > > > identifies OP-TEE > > > > > > > > > specifically. > > > > > > > > > > > > > > > > Also, we don't know how the QTEE will react to this OP-TEE > > > > > > > > specific SMC > > > > > > > > call given it's different variants running on legacy and the > > > > > > > > newer SoCs. > > > > > > > > So I would suggest to better gate OP-TEE presence behind a > > > > > > > > compile time > > > > > > > > check only. > > > > > > > > > > > > > > So you say it's fine to add the optee node, and the driver will > > > > > > > bail out if > > > > > > > OPTEE is not present, but it's not good to call > > > > > > > OPTEE_SMC_CALL_GET_OS_UUID > > > > > > > in the fixup code to enable OPTEE only if present ? > > > > > > > > > > > > > > It's literally the same, my point in > > > > > > > https://lore.kernel.org/all/[email protected]/ > > > > > > > was exactly that, just call OPTEE_SMC_CALL_GET_OS_UUID and add > > > > > > > the OPTEE > > > > > > > node only if present _AND_ if CONFIG_OPTEE is enabled. > > > > > > > > > > > > > > Move the CONFIG_OPTEE enable in a fragment and we're done, you > > > > > > > will only > > > > > > > select OPTEE explicitly on desired platforms, and won't run the > > > > > > > naughty > > > > > > > OPTEE_SMC_CALL_GET_OS_UUID on old crappy platforms. > > > > > > > > > > > > I am still trying to understand what benefit does invoking > > > > > > OPTEE_SMC_CALL_GET_OS_UUID from platform code provides us. Surely it > > > > > > can't be used to detect OP-TEE not present when QTEE is running due > > > > > > to > > > > > > unknown behaviour with QTEE. > > > > > > > > > > Sorry but what exactly do you expect that will happen if you enable > > > > > the OPTEE > > > > > driver when running with QTEE ? > > > > > > > > The OP-TEE SMC calls are not at all supported with QTEE, so the expected > > > > behaviour is undefined. IOW, the OP-TEE SMC ABI is not compatible with > > > > QTEE. However, it's going to be hit and trial method to see what QTEE > > > > responds to OP-TEE SMC calls. So it's not a reliable source of > > > > information we can use to detect which TEE is present or not. > > > > > > So until we know, this change is a no go, we can't just add the /optee > > > node > > > and hope the person building uboot did the right thing. > > > > Not sure why you think Qualcomm platforms are special in this regards > > when similar OP-TEE node additions based on CONFIG_OPTEE exist for other > > platforms, see example here [1] [2] [3]. > > > > The OP-TEE configs will surely be part of a separate config fragment and > > I can add comments there for developer's awareness. > > > > [1] arch/arm/dts/imx8mm-u-boot.dtsi:10 > > [2] arch/arm/dts/imx8mn-u-boot.dtsi:10 > > [3] arch/arm/dts/imx8mp-u-boot.dtsi:11 > > > > > > > > I propose an alternate way, is to check for QTEE and then test for OPTEE. > > > > There are more combinations rather than just QTEE or OP-TEE as follows: > > - Older targets have support for QSEECOM > > - Newer targets with QTEE support > > - Chrome targets without any TEE support > > - IoT targets with OP-TEE support > > > > Do you have any particular mechanism in mind for detecting OP-TEE > > presence at runtime? And surely that has to be well supported on variety > > of SoC where U-Boot is supported as of now. > > OPTEE_SMC_CALL_GET_OS_UUID which works fine on like all the other ARM based > platforms.
Can you share at-least one example of other Arm based platform where this SMC call is used to add OP-TEE DT node? > > It's the only way, and only Qualcomm engineers can answer how to determine > without any risk which TEE is running on the system. The fact that you keep ignoring my responses that OP-TEE SMC ABI is not compatible with QTEE/QSEECOM SMC ABI is not going to change (see [1]). I am not sure why it's a blocker to use CONFIG_OPTEE for OP-TEE DT node addition on Qcom platforms when the same criteria is being used for imx8* platforms already. [1] https://lore.kernel.org/all/aWjrLF9DUPTaSA1c@sumit-xelite/. -Sumit > > Without this, all this discussions is pointless. > > > > > Also, there is added complexity for targets where the developer can't > > change the TZ firmware themselves on Qcom SoCs due to QTI signing > > requirement. > > > > -Sumit > > > > > > > > Neil > > > > > > > > > > > -Sumit > > > > > > > > > > > > > > > > > > > > > Jens, > > > > > > > > > > > > Will it be fine with you to expose is_optee_api() from the OP-TEE > > > > > > driver > > > > > > for the platform code to invoke it independently? Just for the sake > > > > > > of this > > > > > > discussion in case people still insist on it being the right thing > > > > > > to do. > > > > > > > > > > > > -Sumit > > > > > > > > > > > > > > > > > > > > Neil > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > My suggestion would be to make this SMC call if CONFIG_OPTEE > > > > > > > > > is enabled > > > > > > > > > in qcom_psci_fixup(), compare the UUID and add the node if it > > > > > > > > > matches. > > > > > > > > > > > > > > > > That's exactly the first SMC call that U-Boot and Linux OP-TEE > > > > > > > > driver > > > > > > > > does to compare the UUID here [1] and bail out of the driver. I > > > > > > > > don't > > > > > > > > see a value of a redundant invoke in the Qcom specific platform > > > > > > > > code. > > > > > > > > > > > > > > > > [1] drivers/tee/optee/core.c:823: if > > > > > > > > (!is_optee_api(pdata->invoke_fn)) > > > > > > > > > > > > > > > > -Sumit > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > [1] lib/efi_loader/efi_variable_tee.c > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > So I think the more appropriate patch here would be to > > > > > > > > > > > just enable > > > > > > > > > > > OP-TEE in qcom_defconfig (assuming the binary size isn't > > > > > > > > > > > significantly > > > > > > > > > > > affected). > > > > > > > > > > > > > > > > > > > > The OP-TEE driver in U-Boot itself is probed based on DT > > > > > > > > > > and it's not > > > > > > > > > > only specific to Qcom platforms but every other platform > > > > > > > > > > using OP-TEE. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Considering the other patch is based on this assumption > > > > > > > > > > > that if OP-TEE > > > > > > > > > > > support is enabled then the board must be using it, a > > > > > > > > > > > different approach > > > > > > > > > > > is definitely needed. > > > > > > > > > > > > > > > > > > > > Yeah that's true even with TF-A boot flow, there is > > > > > > > > > > possibility to boot > > > > > > > > > > without OP-TEE as well. However, TF-A generally doesn't > > > > > > > > > > provide a > > > > > > > > > > generic option to detect whether OP-TEE is running or not. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > When I was looking into this last year I remember > > > > > > > > > > > discussing this same > > > > > > > > > > > issue from the Linux side, there is a good argument to be > > > > > > > > > > > made that > > > > > > > > > > > OP-TEE support in Linux shouldn't be based on the > > > > > > > > > > > devicetree - > > > > > > > > > > > particularly in the Qualcomm case where whether or not > > > > > > > > > > > OP-TEE is used is > > > > > > > > > > > a simple software change, nothing to do with hardware. > > > > > > > > > > > > > > > > > > > > Sadly it's true for every other silicon vendor too. But > > > > > > > > > > OP-TEE support > > > > > > > > > > based on DT has become an ABI unless migration for OP-TEE > > > > > > > > > > support based > > > > > > > > > > on FF-A comes into picture. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > So in general I'm not particularly keen on this approach, > > > > > > > > > > > I think it > > > > > > > > > > > /might/ be acceptable for U-Boot to have some fixup code > > > > > > > > > > > to add the > > > > > > > > > > > OP-TEE node if OP-TEE is in use with the idea of phasing > > > > > > > > > > > that out in > > > > > > > > > > > favour of runtime detection in the OS itself. I'd also > > > > > > > > > > > expect that fixup > > > > > > > > > > > code to go in the generic U-Boot DT fixup code that runs > > > > > > > > > > > before we jump > > > > > > > > > > > to the OS (like the EFI DT fixup function). > > > > > > > > > > > > > > > > > > > > The EFI DT fixup code is already there based on U-Boot DT. > > > > > > > > > > Have a look > > > > > > > > > > here: > > > > > > > > > > > > > > > > > > > > boot/image-fdt.c:627: fdt_ret = > > > > > > > > > > optee_copy_fdt_nodes(blob); > > > > > > > > > > > > > > > > > > > > In general on Arm platforms there isn't any SMC bus to > > > > > > > > > > detect > > > > > > > > > > dynamically if there is support for OP-TEE or not. That's > > > > > > > > > > why > > > > > > > > > > platform bus was choosen for the U-Boot and Linux OP-TEE > > > > > > > > > > driver. It's > > > > > > > > > > similar to how we have the SCM DT node for Qcom platforms. > > > > > > > > > > > > > > > > > > > > FF-A bus tries to solve that problem to unify that approach > > > > > > > > > > for future > > > > > > > > > > platform but U-Boot hasn't yet gained support for FF-A > > > > > > > > > > based OP-TEE > > > > > > > > > > driver too. > > > > > > > > > > > > > > > > > > > > Anyhow, this is the sanest way I can come up with to enable > > > > > > > > > > OP-TEE > > > > > > > > > > support in a general way for all the Qcom platforms. This > > > > > > > > > > is aligned > > > > > > > > > > with how OP-TEE support is detected for other silicon > > > > > > > > > > vendors too. > > > > > > > > > > > > > > > > > > > > -Sumit > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Kind regards, > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > For more information refer here: > > > > > > > > > > > > https://trustedfirmware-a.readthedocs.io/en/latest/plat/qti/rb3gen2.html > > > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Sumit Garg <[email protected]> > > > > > > > > > > > > --- > > > > > > > > > > > > configs/qcom_tfa_optee_defconfig | 7 +++++++ > > > > > > > > > > > > 1 file changed, 7 insertions(+) > > > > > > > > > > > > create mode 100644 configs/qcom_tfa_optee_defconfig > > > > > > > > > > > > > > > > > > > > > > > > diff --git a/configs/qcom_tfa_optee_defconfig > > > > > > > > > > > > b/configs/qcom_tfa_optee_defconfig > > > > > > > > > > > > new file mode 100644 > > > > > > > > > > > > index 00000000000..c398521770f > > > > > > > > > > > > --- /dev/null > > > > > > > > > > > > +++ b/configs/qcom_tfa_optee_defconfig > > > > > > > > > > > > @@ -0,0 +1,7 @@ > > > > > > > > > > > > +# Configuration for building a generic U-Boot image > > > > > > > > > > > > +# with support for TF-A/OP-TEE based Arm TrustZone > > > > > > > > > > > > stack. > > > > > > > > > > > > + > > > > > > > > > > > > +#include "qcom_defconfig" > > > > > > > > > > > > + > > > > > > > > > > > > +CONFIG_TEE=y > > > > > > > > > > > > +CONFIG_OPTEE=y > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > > > // Casey (she/her) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > // Casey (she/her) > > > > > > > > > > > > > > > > > > > > > > > > >
