- TF-M - lists.trustedfirmware.org

by DeMars, Alan

I'm using the feature-ipc branch and I notice a lot of these warnings in TF-M header files: /*********** WARNING: This is an auto-generated file. Do not edit! ***********/ When are these files generated? I assume they're derived from associated manifest files. When I use cmake to create a "ConfigCoreIPC.cmake" build area, I don't see any header files being generated in the process. Any changes I've made to header files with these warnings are still present. Is there a TF-M cmake configuration that regenerates these files? If so, how do I invoke it so I can more properly reconfigure a custom SP? Alan

7 years

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Re: [TF-M] [Tf-m] [EXTERNAL] Re: Non-secure Client Management

by Miklos Balint

Hi Alan, https://developer.trustedfirmware.org/w/tf_m/planning/ has a roadmap of planned feature support by calendar quarter. NSPM for the thread-based design is not explicitly highlighted but I would expect it to be implemented as part of the Q2 SPM work or Q3 Scheduler work the latest. Any feedback on that or any other aspect of the roadmap is very welcome so we can take that into account when updating the plans. For the TZ functions, please note that these are not proprietary to TF-M but form a standard CMSIS API, a generic RTOS feature for TrustZone-enabled devices: https://www.keil.com/pack/doc/CMSIS/Core/html/group__context__trustzone__fu… Since these calls are direct function calls between NSPE and SPE, the overhead should be in the order of a few dozen clock cycles each, not much more than regular RTOS context switch hooks that would be available in several RTOSes. Are you concerned that this overhead is a major limitation? If so, one enhancement TF-M could provide to support a simplified non-CMSIS-compliant NSPE RTOS implementation is for TZ_LoadContext_S to implement the functionality you described for "SwitchContext", taking only the new MemoryId as argument - the old id is stored in the NSPM database anyway, so the context to be Stored in this case can be inferred by TF-M. If the new context is not secure-accessing, FreeContext can be used as defined by CMSIS. This way TF-M does not introduce proprietary new functions for functionality already defined by the standard. Please note that this solution would still need to be analysed for security implications as TF-M would be making additional assumptions on NSPE state - although I don't see a reason for concern at this point. /M -----Original Message----- From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> On Behalf Of DeMars, Alan via TF-M Sent: 03 February 2019 15:18 To: Ken Liu (Arm Technology China) <Ken.Liu(a)arm.com> Cc: nd <nd(a)arm.com>; tf-m(a)lists.trustedfirmware.org Subject: Re: [Tf-m] [EXTERNAL] Re: Non-secure Client Management Ken, Thank you for your prompt response. Please see my replies below. Alan > Hi Alan, > The proposed APIs are implemented for library mode. It will not work under IPC mode in 'feature-ipc' branch. The support of NSPM for IPC will come later. Is their a feature rollout schedule that I can follow? > The TZ_LoadContext_S() and TZ_StoreContext_S() need to be called every time while secure service accessed NS thread get entering/leaving. It is not combined into one function, because not all NS threads need to access secure service. For those NS threads which do not need to access secure service, these TZ_ APIs are unnecessary to be called. For example, if NS scheduler switches from one secure service accessed thread into the other generic thread, only TZ_StoreContext_S() needs to be called before context switching. To avoid the rather burdensome overhead of calling into the SPM twice on those NS context switches in which either the leaving or entering contexts are secure accessing threads, I propose that a NULL TZ_MemoryId_t be defined so that a single TZ_SwitchContext_S() function with two TZ_MemoryId_t arguments can be called. The NULL TZ_MemoryId_t would be passed to identify an entering or leaving context that is not secure accessing. > The method of blocking the caller client is based on scenarios. If there are some 'wait' is necessary while secure service is working (waiting for secure hardware IRQ as an example), the method you mentioned may be involved (special return value with an NS IRQ notification). This functionality is not in place right now. > > -Ken > >> -----Original Message----- >> From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> On Behalf Of >> DeMars, Alan via TF-M >> Sent: Sunday, February 3, 2019 9:17 AM >> To: tf-m(a)lists.trustedfirmware.org >> Subject: [Tf-m] Non-secure Client Management >> >> Regarding the Non-secure Client Management proposal: >> >> >> https://developer.trustedfirmware.org/w/tf_m/design/ns_client_managem >> ent/ >> >> I notice that the veneers for the proposed APIs are in s_veneers.o. >> Does this mean that the proposal has been adopted and implemented? Is >> it functional in the current feature-ipc branch? >> >> I have a question about the TZ_LoadContext_S() and TZ_StoreContext_S() APIs: >> Is it expected that each context switch in the NS world will be >> signaled by calls to each of these APIs indicating the "entering" >> context and "leaving" context respectively? If so, then why not >> collapse these two APIs into one called >> TZ_SwitchContext__S() and pass both the "entering" and "leaving" >> TZ_MemoryId_t's as arguments? >> >> Or is TZ_StoreContext_S() only to be called when a NS context will >> never call into the SPM again? If that is the case, why isn't >> TZ_FreeModuleContext_S() sufficient? >> >> Regarding the "Concurrent secure service requests" discussion, what >> does "a non-secure client is blocked on an asynchronous secure service completion"? >> Would this be achieved by a special return status from psa_call() >> indicating that the current service request is in process and will >> complete later on? The psa_call() calling thread would then block on >> a semaphore that would be released by a dedicated NS IRQ interrupt? Is any of this functionality in place yet? >> >> Alan

7 years

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Re: [TF-M] IRQ handling by Secure Partitions proposal

by Miklos Balint

Hi Alan, 0, One thing to point out is that my proposal only covers the "Library" or function-call-based model that was the only one implemented on TF-M master branch at the time of writing. PSA Firmware Framework v1.0 with its IPC mechanism has its own design of how interrupts are supposed to be handled by secure threads - my proposal intends to complement that with the same functionality for the other operating model. This clarification addresses point 5 as well, I believe. 1, SPM "Acknowledges the interrupt": this is not the best wording. Actually this is very bad wording. What I meant to say is that SPM's own interrupt handler is started - which is a hardware action, not one by SPM - and SPM ISR in turn masks the interrupt line in NVIC. As you rightly point out, the peripheral itself is of no concern to SPM, that's the business for partition code, either in its own Partition ISR, or a service function. 2. This means that secure PSP is saved for the pre-empted context, set to the stack of the partition that's the owner of the interrupt line, and any additional housekeeping associated with a context switch (PSPLIM setup, isolation re-configuration, privilege setting - all according to the properties of the partition that is to be activated). Lastly, a mock context is created on the partition stack so that the Partition ISR can be activated with an exception return from the SPM ISR. 3a. The Partition ISR is activated by SPM ISR by doing an exception return to the start address of e.g. UART1_ISR() function. In order for this TF-M first needs to create the mock context mentioned in my point 2. The discussion of the stack frame in the text is meant to clarify that there are two possibilities that need to be considered: if the partition is idle, i.e. there are no ongoing service requests in its context, its stack pointer is either at a default value or - potentially - there's no stack associated with the partition. In that case a stack frame needs to be initialized and the mock context set up there. If the partition is handling a request, its original stack pointer needs to be used as the start address for the mock context used for exception return. 3b. After execution of the Partition ISR, execution is returned to the SPM ISR. At this point, SPM can decide to either re-activate the original context that had been pre-empted by the interrupt, or, can take a scheduling decision to activate a different context, e.g. the partition that had called psa_wait(). 4. The current implementation does not allow for the pre-emption of a secure context by non-secure scheduling events, but that is a limitation that could likely be lifted depending on some basic policies that have to be set up by the system integrator. In such a case the NS thread would be blocked waiting on the completion of the secure service, but a pre-emptive NS OS could schedule a different thread if the time slice of the caller thread runs out. Other options are subject to investigation at this point. ... Please let me know if any of the points I've addressed provide clarity instead of making the design more obscure, in which case I would update the design proposal with the extra information. :) And of course let me know if you have further questions. Regards Miklos -----Original Message----- From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> On Behalf Of DeMars, Alan via TF-M Sent: 02 February 2019 04:29 To: tf-m(a)lists.trustedfirmware.org Subject: [Tf-m] IRQ handling by Secure Partitions proposal Regarding the "SPM behavior" discussion in the "Secure Partition Interrupt Handling" proposal: 1) What is meant by the SPM "Acknowledges the interrupt"? I understand "masks the hardware interrupt line" but I don't see how the SPM can know how to acknowledge a particular peripheral's interrupt. I think acknowledging the interrupt should be done by the "Partition ISR" dedicated to the interrupt, or within the corresponding SP's main loop upon return from psa_wait(). 2) What does "Sets up execution environment for the secure partition" mean, precisely? 3) Can you expand on the "Execute Partition ISR" paragraph a little? I assume you mean that, for instance, the registered UART1_isr() function is called. The discussion of the ISR stack frame I don't really follow. And from the description, I'm not sure when the SP is scheduled to run again to deal with the ISR it was waiting for. 4) A secure partition that depends on an interrupt begs the question of what happens to the NS thread that has called into the SP requesting some service that depends on a subsequent asynchronous event (ISR) to complete the request. The psa_call() function as currently implemented doesn't "block" in the traditional OS sense (ie the thread's context and state are not saved in a manner that allows another task thread to run while the psa_call() is stalled in the SPM waiting for an ISR. 5) The details of SP thread pre-emption and re-entrancy need to be described. Alan -- TF-M mailing list TF-M(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-m

7 years

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Re: [TF-M] [Tf-m] Issues porting to new toolchain

by Mate Toth-Pal

Hi Thomas, 1) If you can provide implementations in standard C, then yes, it can be a benefit 2) Yes, I think that would make the code review easier. 3) You are right, adding ifdefs to C files should not be the way to go. As GNUARM doesn't provide symbols like this, we could easily solve this problem by creating the symbols in the ld file to be the same as the ones generated by the ARMCLANG toolchain. One option is to do the same for the EWARM toolchain as for GNUARM. I had a quick look at the EWARM Development Guide, and it seems that the linker configuration file supports this feature (exporting symbols, and using expressions with start/end addresses of elf sections). Another way to go would be to move the REGION_DECLARE, REGION_NAME, and related macros to a compiler specific header file, like tfm_compiler.h. Then this file could be placed in the platforms' toolchain specific directories. This solution would have the benefit, that the multiple definitions of the macros would be reduced to a single one. However to me this seems to be a greater effort: - The build system have to be modified to add the platform specific folder as include folder for compilation - The macros should be restructured a bit, as there would be a need for LOAD_REGION_DECLARE(...), EXECUTION_REGION_DECLARE_RW(...), EXECUTION_REGION_DECLARE_RO(...) and more (at least based on my quick look at the code) - All the source files have to be updated to use the new macros and include the specific header 4) The way to solve this could be to create a new function in the Compiler<tooolchain>Common.cmake files, called something like get_pre_include_parameter, that generates the proper option (--preinclude of -include) and call that function in BuildMbedtls.cmake Regards, Mate -----Original Message----- From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> On Behalf Of Thomas Törnblom via TF-M Sent: 04 February 2019 15:41 To: DeMars, Alan via TF-M <tf-m(a)lists.trustedfirmware.org> Subject: [Tf-m] Issues porting to new toolchain Greetings, I am working on adding IAR Embedded Workbench for ARM (EWARM) as a supported toolchain for TF-M and I would like to discuss some of the issues I've run into before I start issuing PR:s. 1) The current TF-M source uses non-standard gcc extensions which EWARM does not support. I assume it should not be an issue converting this code into standard C, that would only help porting to other toolchains as well. 2) Should I create separate PR:s for these changes and the toolchain changes? 3) In some places (tfm_core.c, ...) there are hardwired references to symbols like Image$$TFM_UNPRIV_SCRATCH$$ZI$$Base, Image$$TFM_UNPRIV_SCRATCH$$ZI$$Limit. Our toolchain would use symbols like TFM_UNPRIV_SCRATCH$$Base and TFM_UNPRIV_SCRATCH$$Limit instead. What to do about this? Adding #ifdefs in the .c files will be messy and I'd like some cleaner solution. 4) Some common cmake files contains hardwired option names like "-include" (BuildMbedtls.cmake) Our toolchain uses "--preinclude" instead and I think this ought to be handled in the compiler specific cmake files instead. -- *Thomas Törnblom*, /Product Engineer/ IAR Systems AB Box 23051, Strandbodgatan 1 SE-750 23 Uppsala, SWEDEN Mobile: +46 76 180 17 80 Fax: +46 18 16 78 01 E-mail: thomas.tornblom(a)iar.com <mailto:thomas.tornblom@iar.com> Website: www.iar.com <http://www.iar.com> Twitter: www.twitter.com/iarsystems <http://www.twitter.com/iarsystems> -- TF-M mailing list TF-M(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-m

7 years

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Issues porting to new toolchain

by Thomas Törnblom

Greetings, I am working on adding IAR Embedded Workbench for ARM (EWARM) as a supported toolchain for TF-M and I would like to discuss some of the issues I've run into before I start issuing PR:s. 1) The current TF-M source uses non-standard gcc extensions which EWARM does not support. I assume it should not be an issue converting this code into standard C, that would only help porting to other toolchains as well. 2) Should I create separate PR:s for these changes and the toolchain changes? 3) In some places (tfm_core.c, ...) there are hardwired references to symbols like Image$$TFM_UNPRIV_SCRATCH$$ZI$$Base, Image$$TFM_UNPRIV_SCRATCH$$ZI$$Limit. Our toolchain would use symbols like TFM_UNPRIV_SCRATCH$$Base and TFM_UNPRIV_SCRATCH$$Limit instead. What to do about this? Adding #ifdefs in the .c files will be messy and I'd like some cleaner solution. 4) Some common cmake files contains hardwired option names like "-include" (BuildMbedtls.cmake) Our toolchain uses "--preinclude" instead and I think this ought to be handled in the compiler specific cmake files instead. -- *Thomas Törnblom*, /Product Engineer/ IAR Systems AB Box 23051, Strandbodgatan 1 SE-750 23 Uppsala, SWEDEN Mobile: +46 76 180 17 80 Fax: +46 18 16 78 01 E-mail: thomas.tornblom(a)iar.com <mailto:thomas.tornblom@iar.com> Website: www.iar.com <http://www.iar.com> Twitter: www.twitter.com/iarsystems <http://www.twitter.com/iarsystems>

7 years

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Re: [Tf-m] [TF-M] How to run PSA API compliance tests with TF-M SST service

by Shebu Varghese Kuriakose

Adding TF-M mailing list and Prasanth Hi Murat, Looking at the list of subscribed members, you are not yet registered to TF-M mailing list. Please try subscribing using the link in https://www.trustedfirmware.org/contact/. You will receive a mail which you need to acknowledge before you get subscribed. Check your spam as well for the mail asking for acknowledgement. On the topic below, the extended tests are for testing against the optional/extended SST Protected Storage APIs. These APIs are optional and so not required to pass for PSA Functional API certification. The SST patch set below doesn’t support those optional SST PS APIs. From what I last heard, Marc and team has verified all the other mandatory SST PS Tests on MuscaA using the patches below. TF-M team or Prasanth might be able to advise on what might be going wrong. Regards, Shebu -----Original Message----- From: murat(a)za-ya.co <murat(a)za-ya.co> Sent: Sunday, February 3, 2019 10:29 AM To: Marc Moreno Berengue <Marc.MorenoBerengue(a)arm.com> Cc: nd <nd(a)arm.com>; Shebu Varghese Kuriakose <Shebu.VargheseKuriakose(a)arm.com> Subject: RE: [Tf-m] [TF-M] How to run PSA API compliance tests with TF-M SST service Dear Marc, Thank you for introductions. We are now running PSA SST tests on Musca board, and as we see there are only three test suites (p011, p012, p013), the other test suites are empty. And when we run the PSA SST tests, SST tests skip even existing three test cases. This is because the first test case asks for supported API and expects " PSA_PS_SUPPORT_SET_EXTENDED " static const test_data p011_data[] = { { VAL_PS_GET_SUPPORT, PSA_PS_SUPPORT_SET_EXTENDED /* Check if optional PS API supported */ }, And TF-m (https://review.trustedfirmware.org/#/c/trusted-firmware-m/+/589/ ) does not the support extended PSA API yet as we see from enum tfm_sst_err_t tfm_sst_get_support(uint32_t *support_flags) { /* * This function returns a bitmask with flags set for all of the optional * features supported by the SST service implementation. * * SST service does not support the optional extended PSA PS API yet. <<<<<<<<<<<<<<<<<<<<< NO SUPPORT */ *support_flags = 0; <<<<<<<<<<<<<<<<<<<<< NO SUPPORT return TFM_SST_ERR_SUCCESS; } And PSA Test Suite skips the all remaining test case if there is no EXTENDED API Support. 0.000 - 00>Test Case not needed as Optional PS APIs are not supported. 0.000 - 00>TEST RESULT: SKIPPED (Skip Code=0x2b) 0.000 - 00>****************************************** 0.000 - 00>************ Protected Storage Suite Report ********** 0.000 - 00>TOTAL TESTS : 3 0.000 - 00>TOTAL PASSED : 0 0.000 - 00>TOTAL SIM ERROR : 0 0.000 - 00>TOTAL FAILED : 0 0.000 - 00>TOTAL SKIPPED : 3 0.000 - 00>****************************************** 0.000 - 00>Entering standby.. Is it the expected behaviour for Musca Port or are we missing something? (We are registered but we don’t receive any e-mail from the TF-m mail list, I don’t know how to see your response 😊 ) Thank you. Best Regards. Murat -----Original Message----- From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> On Behalf Of Marc Moreno Berengue via TF-M Sent: 01 February 2019 18:25 To: tf-m(a)lists.trustedfirmware.org Cc: nd <nd(a)arm.com> Subject: [Tf-m] [TF-M] How to run PSA API compliance tests with TF-M SST service Hi all, The Secure Storage (SST) service has been updated to align it with the PSA Protected Storage APIs version 1.0. There are a set of patches which implements this change. Please, find more information about those changes in the following ticket: https://developer.trustedfirmware.org/T218 It's possible to run the PSA API Compliance tests (https://github.com/ARM-software/psa-arch-tests/tree/master/api-tests/dev_ap…) with the TF-M SST service by following the instructions below. (The instructions assume that psa-arch-tests and trusted-firmware-m directories are at the same level in the filesystem): 1. Checkout https://github.com/ARM-software/psa-arch-tests/ 2. Checkout https://review.trustedfirmware.org/#/c/trusted-firmware-m/+/589/ 3. Copy the `interface/include/psa_protected_storage.h` to `interface/include/psa/protected_storage.h` as this is the header name expected by the PSA API Compliance tests 4. Build the SST tests for the PSA API compliance as described in the `psa-arch-tests/api-tests` for one of the supported targets, providing the include path of the TF-M interface (i.e. trusted-firmware-m/interface/include). Set crypto and internal trusted storage as not implemented in `psa-arch-tests/api-tests/platform/targets/<TARGET_NAME>/Makefile`. Set PSA_CRYPTO_IMPLEMENTED:=0 and PSA_INTERNAL_TRUSTED_STORAGE_IMPLEMENTED:=0 * The list of tests being run is specified in the file `psa-arch-tests/api-tests/dev_apis/protected_storage/testsuite.db` * For example, this command will build the tests for AN521 "./tools/scripts/setup.sh --target tgt_dev_apis_tfm_an521 --toolchain ARMCLANG --cpu_arch armv8m_ml --verbose 2 --suite protected_storage --include ../../trusted-firmware-m/interface/include --archive_tests" 5. Build TF-M by using the ConfigPsaApiTest.cmake, enabling the PSA API Compliance tests for SST service by adding the following cmake switch during the configuration step: "-DPSA_API_TEST_SECURE_STORAGE=ON" * For example, this command will build the TF-M + NS app with PSA API Protected Storage tests for AN521 "cmake -G"Unix Makefiles" -DPROJ_CONFIG=`readlink -f ../ConfigPsaApiTest.cmake` -DTARGET_PLATFORM=AN521 -DCOMPILER=ARMCLANG -DPSA_API_TEST_SECURE_STORAGE=ON ../" This will make our NS test app run a subset of the PSA API compliance tests for SST service. Thanks, Marc Moreno -- TF-M mailing list TF-M(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-m

7 years

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Re: [Tf-m] [EXTERNAL] Re: Non-secure Client Management

by DeMars, Alan

Ken, Thank you for your prompt response. Please see my replies below. Alan > Hi Alan, > The proposed APIs are implemented for library mode. It will not work under IPC mode in 'feature-ipc' branch. The support of NSPM for IPC will come later. Is their a feature rollout schedule that I can follow? > The TZ_LoadContext_S() and TZ_StoreContext_S() need to be called every time while secure service accessed NS thread get entering/leaving. It is not combined into one function, because not all NS threads need to access secure service. For those NS threads which do not need to access secure service, these TZ_ APIs are unnecessary to be called. For example, if NS scheduler switches from one secure service accessed thread into the other generic thread, only TZ_StoreContext_S() needs to be called before context switching. To avoid the rather burdensome overhead of calling into the SPM twice on those NS context switches in which either the leaving or entering contexts are secure accessing threads, I propose that a NULL TZ_MemoryId_t be defined so that a single TZ_SwitchContext_S() function with two TZ_MemoryId_t arguments can be called. The NULL TZ_MemoryId_t would be passed to identify an entering or leaving context that is not secure accessing. > The method of blocking the caller client is based on scenarios. If there are some 'wait' is necessary while secure service is working (waiting for secure hardware IRQ as an example), the method you mentioned may be involved (special return value with an NS IRQ notification). This functionality is not in place right now. > > -Ken > >> -----Original Message----- >> From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> On Behalf Of DeMars, >> Alan via TF-M >> Sent: Sunday, February 3, 2019 9:17 AM >> To: tf-m(a)lists.trustedfirmware.org >> Subject: [Tf-m] Non-secure Client Management >> >> Regarding the Non-secure Client Management proposal: >> >> >> https://developer.trustedfirmware.org/w/tf_m/design/ns_client_management/ >> >> I notice that the veneers for the proposed APIs are in s_veneers.o. Does this >> mean that the proposal has been adopted and implemented? Is it functional in >> the current feature-ipc branch? >> >> I have a question about the TZ_LoadContext_S() and TZ_StoreContext_S() APIs: >> Is it expected that each context switch in the NS world will be signaled by calls to >> each of these APIs indicating the "entering" context and "leaving" context >> respectively? If so, then why not collapse these two APIs into one called >> TZ_SwitchContext__S() and pass both the "entering" and "leaving" >> TZ_MemoryId_t's as arguments? >> >> Or is TZ_StoreContext_S() only to be called when a NS context will never call into >> the SPM again? If that is the case, why isn't TZ_FreeModuleContext_S() >> sufficient? >> >> Regarding the "Concurrent secure service requests" discussion, what does "a >> non-secure client is blocked on an asynchronous secure service completion"? >> Would this be achieved by a special return status from psa_call() indicating that >> the current service request is in process and will complete later on? The psa_call() >> calling thread would then block on a semaphore that would be released by a >> dedicated NS IRQ interrupt? Is any of this functionality in place yet? >> >> Alan >> -- >> TF-M mailing list >> TF-M(a)lists.trustedfirmware.org >> https://lists.trustedfirmware.org/mailman/listinfo/tf-m > -- > TF-M mailing list > TF-M(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-m

7 years

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Re: [Tf-m] Non-secure Client Management

by Ken Liu (Arm Technology China)

Hi Alan, The proposed APIs are implemented for library mode. It will not work under IPC mode in 'feature-ipc' branch. The support of NSPM for IPC will come later. The TZ_LoadContext_S() and TZ_StoreContext_S() need to be called every time while secure service accessed NS thread get entering/leaving. It is not combined into one function, because not all NS threads need to access secure service. For those NS threads which do not need to access secure service, these TZ_ APIs are unnecessary to be called. For example, if NS scheduler switches from one secure service accessed thread into the other generic thread, only TZ_StoreContext_S() needs to be called before context switching. The method of blocking the caller client is based on scenarios. If there are some 'wait' is necessary while secure service is working (waiting for secure hardware IRQ as an example), the method you mentioned may be involved (special return value with an NS IRQ notification). This functionality is not in place right now. -Ken > -----Original Message----- > From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> On Behalf Of DeMars, > Alan via TF-M > Sent: Sunday, February 3, 2019 9:17 AM > To: tf-m(a)lists.trustedfirmware.org > Subject: [Tf-m] Non-secure Client Management > > Regarding the Non-secure Client Management proposal: > > > https://developer.trustedfirmware.org/w/tf_m/design/ns_client_management/ > > I notice that the veneers for the proposed APIs are in s_veneers.o. Does this > mean that the proposal has been adopted and implemented? Is it functional in > the current feature-ipc branch? > > I have a question about the TZ_LoadContext_S() and TZ_StoreContext_S() APIs: > Is it expected that each context switch in the NS world will be signaled by calls to > each of these APIs indicating the "entering" context and "leaving" context > respectively? If so, then why not collapse these two APIs into one called > TZ_SwitchContext__S() and pass both the "entering" and "leaving" > TZ_MemoryId_t's as arguments? > > Or is TZ_StoreContext_S() only to be called when a NS context will never call into > the SPM again? If that is the case, why isn't TZ_FreeModuleContext_S() > sufficient? > > Regarding the "Concurrent secure service requests" discussion, what does "a > non-secure client is blocked on an asynchronous secure service completion"? > Would this be achieved by a special return status from psa_call() indicating that > the current service request is in process and will complete later on? The psa_call() > calling thread would then block on a semaphore that would be released by a > dedicated NS IRQ interrupt? Is any of this functionality in place yet? > > Alan > -- > TF-M mailing list > TF-M(a)lists.trustedfirmware.org > https://lists.trustedfirmware.org/mailman/listinfo/tf-m

7 years

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Non-secure Client Management

by DeMars, Alan

Regarding the Non-secure Client Management proposal: https://developer.trustedfirmware.org/w/tf_m/design/ns_client_management/ I notice that the veneers for the proposed APIs are in s_veneers.o. Does this mean that the proposal has been adopted and implemented? Is it functional in the current feature-ipc branch? I have a question about the TZ_LoadContext_S() and TZ_StoreContext_S() APIs: Is it expected that each context switch in the NS world will be signaled by calls to each of these APIs indicating the "entering" context and "leaving" context respectively? If so, then why not collapse these two APIs into one called TZ_SwitchContext__S() and pass both the "entering" and "leaving" TZ_MemoryId_t's as arguments? Or is TZ_StoreContext_S() only to be called when a NS context will never call into the SPM again? If that is the case, why isn't TZ_FreeModuleContext_S() sufficient? Regarding the "Concurrent secure service requests" discussion, what does "a non-secure client is blocked on an asynchronous secure service completion"? Would this be achieved by a special return status from psa_call() indicating that the current service request is in process and will complete later on? The psa_call() calling thread would then block on a semaphore that would be released by a dedicated NS IRQ interrupt? Is any of this functionality in place yet? Alan

7 years

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IRQ handling by Secure Partitions proposal

by DeMars, Alan

Regarding the "SPM behavior" discussion in the "Secure Partition Interrupt Handling" proposal: 1) What is meant by the SPM "Acknowledges the interrupt"? I understand "masks the hardware interrupt line" but I don't see how the SPM can know how to acknowledge a particular peripheral's interrupt. I think acknowledging the interrupt should be done by the "Partition ISR" dedicated to the interrupt, or within the corresponding SP's main loop upon return from psa_wait(). 2) What does "Sets up execution environment for the secure partition" mean, precisely? 3) Can you expand on the "Execute Partition ISR" paragraph a little? I assume you mean that, for instance, the registered UART1_isr() function is called. The discussion of the ISR stack frame I don't really follow. And from the description, I'm not sure when the SP is scheduled to run again to deal with the ISR it was waiting for. 4) A secure partition that depends on an interrupt begs the question of what happens to the NS thread that has called into the SP requesting some service that depends on a subsequent asynchronous event (ISR) to complete the request. The psa_call() function as currently implemented doesn't "block" in the traditional OS sense (ie the thread's context and state are not saved in a manner that allows another task thread to run while the psa_call() is stalled in the SPM waiting for an ISR. 5) The details of SP thread pre-emption and re-entrancy need to be described. Alan

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