May 2019 - Devel - lists.sel4.systems

Changing initial thread cnode guard
by Clifford, Alexandra - 0553 - MITLL 16 May '19

16 May '19

I am attempting to prototype an seL4 based system that ideally will have multiple threads, each with their own CSpaces which are each a tree e.g. not rooted in the initial cnode. My strategy here is to 1. chain new cnodes off of the initial cnode in the initial thread, and 2. Create a new thread TCB etc., revoke the initial cnode caps and set the new cnode cap as it’s own cnode root in that new thread. I have run into some issues at step 1 and am writing to ask if this is a viable strategy. Perhaps I am misunderstanding something but chaining in this way does not seem possible if all 32 bits are to be resolved in searching the initial cnode, so I am not certain if this strategy will work. Is it possible to configure the initial cnode guard to be something other than 32 bits? I have searched through the config of the kernel and cannot find some easily changed parameter for compile time, and for runtime I have tried to use the TCB_SetSpace and TCB_Configure on the initial thread to change the guard but this has lead to other problems. If I set it to something like 16, does this mean that all of the slot indices in the bootinfo struct are no longer valid as being set at 0x0, 0x1, etc and now will be at half word indices? It is very unclear to me from the documentation how this works but perhaps I am missing something. Setting it to something like 4 leads to an explicit TCB illegal operation and something larger like 19 returns seL4_Error 3 illegal op when I try to create new cnodes via untyped_retype from the init cnode. Is there something obvious that I am missing? I wonder if this is even possible—having cnodes not rooted in the initial cnode. Or if it is possible, is there some other mechanism to create a new cnode that is not rooted in the initial cnode? It is also probably important to note that due to constraints I am not able to use any of the nice sel4_libs provided to help with this. Thanks very much in advance for any help. Alexandra Clifford, MS 05-53 Secure Resilient Systems and Technology MIT Lincoln Laboratory 244 Wood st., Lexington MA 02421 Email: Alexandra.Clifford(a)ll.mit.edu

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Possible newbie question: What are ".bf"-files belonging to the seL4 code base?
by Mike Epoch 15 May '19

15 May '19

Hi! I am new to this list so please forgive me if this question has been asked before. The seL4 code base contains a slew of files with a file type of "bf". These files seem to define packed structs that are to fit into words or d-words. An example of that would be file kernel/libsel4/mode_include/64/sel4/shared_types.bf which can be obtained (as part of an entire source tree, of course) via repo init -u https://github.com/seL4/sel4test-manifest.git followed by repo sync. What I find curious is that these files do not adhere to (common) C syntax yet they are fed into GCC and GCC swallows them. This file format appears to be an extension to GCC. I could not find any documentation on any such extension. I would be grateful if anyone could point me to some kind of documentation pertaining to it. Regards Mike

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Using ARM GIC Virtualization Extensions with seL4
by dan pittman 10 May '19

10 May '19

Hi all! I'm currently trying to understand something about the use of the virtualization extensions available in the PL-400 interrupt controller in seL4. It all starts with this sentence: > The hypervisor supports virtualization also by using address translation tables to trap accesses that the virtual machines make to the virtual distributor. The hypervisor determines the effect of these accesses and might typically update the virtual interface control registers as a result. Source: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0471b/CHDIHI… My interpretation of this is that by using the IPA which is available with arm hyp, the hardware can trap accesses to the GIC from the guest and "redirect" those accesses to the physical GIC. From this, I draw the conclusion that the need for a completely virtualized GIC when using these extensions is not necessary. However, in seL4—due to the way in which it manages interrupts by handling the hardware interactions itself and instead invoking an endpoint—the use of these extensions in this way is not possible. I'm curious if this understanding is correct, and if not, I welcome any clarity y'all can provide! cheers, dan

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BeagleBone and CAmkES app picoserver
by KAP Benjamin 06 May '19

06 May '19

Hello I am trying to compile the CAmkES app picoserver for the BeagleBone Black but I do encounter some errors which I cannot manage to solve. Steps: - I repo synced the latest camkes-manifest which was added support for the BeagleBone - added am335x implementations to the Ethdriver global-component - created subfolder and issued ../init-build.sh -DPLATFORM=am335x -DSIMULATION=0 -DAARCH32=1 -DCAMKES_APP=picoserver - ninja Errors: [1/48] Building C object projects/util_libs/libethdrivers/CMakeFiles/ethdrivers.dir/src/plat/am335x/cpsw/cpswif.c.obj FAILED: projects/util_libs/libethdrivers/CMakeFiles/ethdrivers.dir/src/plat/am335x/cpsw/cpswif.c.obj ccache /usr/bin/arm-linux-gnueabi-gcc --sysroot=/host/PICO -DHAVE_AUTOCONF -I../projects/util_libs/libethdrivers/src/plat/am335x/cpsw -I../projects/util_libs/libethdrivers/include -I../projects/util_libs/libethdrivers/plat_include/am335x -I../projects/util_libs/libethdrivers/arch_include/arm -Iautoconf -Ikernel/gen_config -Ielfloader-tool/gen_config -Ilibsel4/gen_config -Iprojects/camkes-tool/libsel4camkes/gen_config -Iprojects/capdl/capdl-loader-app/gen_config -Iprojects/projects_libs/libusbdrivers/gen_config -Iprojects/rumprun/gen_config -Iprojects/seL4_libs/libsel4vka/gen_config -Iprojects/seL4_libs/libsel4utils/gen_config -Iprojects/seL4_libs/libsel4platsupport/gen_config -Iprojects/seL4_libs/libsel4serialserver/gen_config -Iprojects/seL4_libs/libsel4debug/gen_config -Iprojects/seL4_libs/libsel4test/gen_config -Iprojects/seL4_libs/libsel4muslcsys/gen_config -Iprojects/seL4_libs/libsel4vmm/gen_config -Iprojects/seL4_projects_libs/libsel4arm-vmm/gen_config -Iprojects/util_libs/libutils/gen_config -Iprojects/util_libs/libplatsupport/gen_config -Iprojects/util_libs/libethdrivers/gen_config -Iprojects/util_libs/libpicotcp/gen_config -Iprojects/musllibc/build-temp/stage/include -I../projects/util_libs/libplatsupport/include -I../projects/util_libs/libplatsupport/plat_include/am335x -I../projects/util_libs/libplatsupport/arch_include/arm -I../projects/util_libs/libutils/include -I../projects/util_libs/libutils/arch_include/arm -Iprojects/util_libs/libpicotcp/picotcp_external/picotcp/build/include -march=armv7-a -marm -D__KERNEL_32__ -g -nostdinc -fno-pic -fno-pie -fno-stack-protector -fno-asynchronous-unwind-tables -ftls-model=local-exec -mfloat-abi=softfp -std=gnu11 -MD -MT projects/util_libs/libethdrivers/CMakeFiles/ethdrivers.dir/src/plat/am335x/cpsw/cpswif.c.obj -MF projects/util_libs/libethdrivers/CMakeFiles/ethdrivers.dir/src/plat/am335x/cpsw/cpswif.c.obj.d -o projects/util_libs/libethdrivers/CMakeFiles/ethdrivers.dir/src/plat/am335x/cpsw/cpswif.c.obj -c ../projects/util_libs/libethdrivers/src/plat/am335x/cpsw/cpswif.c In file included from ../projects/util_libs/libethdrivers/src/plat/am335x/cpsw/cpswif.c:47:0: ../projects/util_libs/libethdrivers/src/plat/am335x/cpsw/../lwiplib.h:46:22: fatal error: lwip/opt.h: No such file or directory #include <lwip/opt.h> ^ compilation terminated. [2/48] Performing build step for 'parse_capdl_tool' make: Nothing to be done for 'all'. [3/48] Building C object projects/util_libs/libethdrivers/CMakeFiles/ethdrivers.dir/src/plat/am335x/beaglebone.c.obj FAILED: projects/util_libs/libethdrivers/CMakeFiles/ethdrivers.dir/src/plat/am335x/beaglebone.c.obj ccache /usr/bin/arm-linux-gnueabi-gcc --sysroot=/host/PICO -DHAVE_AUTOCONF -I../projects/util_libs/libethdrivers/src/plat/am335x/cpsw -I../projects/util_libs/libethdrivers/include -I../projects/util_libs/libethdrivers/plat_include/am335x -I../projects/util_libs/libethdrivers/arch_include/arm -Iautoconf -Ikernel/gen_config -Ielfloader-tool/gen_config -Ilibsel4/gen_config -Iprojects/camkes-tool/libsel4camkes/gen_config -Iprojects/capdl/capdl-loader-app/gen_config -Iprojects/projects_libs/libusbdrivers/gen_config -Iprojects/rumprun/gen_config -Iprojects/seL4_libs/libsel4vka/gen_config -Iprojects/seL4_libs/libsel4utils/gen_config -Iprojects/seL4_libs/libsel4platsupport/gen_config -Iprojects/seL4_libs/libsel4serialserver/gen_config -Iprojects/seL4_libs/libsel4debug/gen_config -Iprojects/seL4_libs/libsel4test/gen_config -Iprojects/seL4_libs/libsel4muslcsys/gen_config -Iprojects/seL4_libs/libsel4vmm/gen_config -Iprojects/seL4_projects_libs/libsel4arm-vmm/gen_config -Iprojects/util_libs/libutils/gen_config -Iprojects/util_libs/libplatsupport/gen_config -Iprojects/util_libs/libethdrivers/gen_config -Iprojects/util_libs/libpicotcp/gen_config -Iprojects/musllibc/build-temp/stage/include -I../projects/util_libs/libplatsupport/include -I../projects/util_libs/libplatsupport/plat_include/am335x -I../projects/util_libs/libplatsupport/arch_include/arm -I../projects/util_libs/libutils/include -I../projects/util_libs/libutils/arch_include/arm -Iprojects/util_libs/libpicotcp/picotcp_external/picotcp/build/include -march=armv7-a -marm -D__KERNEL_32__ -g -nostdinc -fno-pic -fno-pie -fno-stack-protector -fno-asynchronous-unwind-tables -ftls-model=local-exec -mfloat-abi=softfp -std=gnu11 -MD -MT projects/util_libs/libethdrivers/CMakeFiles/ethdrivers.dir/src/plat/am335x/beaglebone.c.obj -MF projects/util_libs/libethdrivers/CMakeFiles/ethdrivers.dir/src/plat/am335x/beaglebone.c.obj.d -o projects/util_libs/libethdrivers/CMakeFiles/ethdrivers.dir/src/plat/am335x/beaglebone.c.obj -c ../projects/util_libs/libethdrivers/src/plat/am335x/beaglebone.c ../projects/util_libs/libethdrivers/src/plat/am335x/beaglebone.c:17:24: fatal error: lwip/netif.h: No such file or directory #include <lwip/netif.h> ^ compilation terminated. ninja: build stopped: subcommand failed. Any help is very much appreciated. Best regards, Benjamin P.S. The file projects/util_libs/libplatsupport/plat_include/am335x/platsupport/plat/timer.h contains the static UNUSED timer_properties_t dmt_properties which caused errors on compilation too. (I deleted the lines since they arent used anyways)

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