April 2022 - Devel - lists.sel4.systems

Unrecognized OPCODE fence.i/csrw
by porter.188＠osu.edu 13 Apr '22

13 Apr '22

I'm trying to setup a development machine for seL4 work. I would like to use v12.1.0. I setup seL4test-manifest per instructions here https://docs.sel4.systems/Hardware/spike.html repo init -u https://github.com/seL4/sel4test-manifest.git repo sync mkdir cbuild cd cbuild ../init-build.sh -DPLATFORM=spike -DRISCV64=1 # The default cmake wrapper sets up a default configuration for the target platform. # To change individual settings, run `ccmake` and change the configuration # parameters to suit your needs. ninja # If your target binaries can be executed in an emulator/simulator, and if # our build system happens to support that target emulator, then this script # might work for you: ./simulate I used repo init -u https://github.com/seL4/sel4test-manifest.git -b refs/tags/12.1.0 to be sure I got 12.1.0 but it doesn't matter, both branches/tags give the same error when I configure/compile. $ ../init-build.sh -DPLATFORM=spike -DRISCV64=1 -DSIMULATION=1 loading initial cache file /mnt/data/sel4test/projects/sel4test/settings.cmake -- Set platform details from PLATFORM=spike -- KernelPlatform: spike -- Setting from flags KernelSel4Arch: riscv64 -- Found seL4: /mnt/data/sel4test/kernel -- Found GCC with prefix riscv64-unknown-linux-gnu- -- Found GCC with prefix riscv64-unknown-linux-gnu- -- The C compiler identification is GNU 10.2.0 -- The CXX compiler identification is GNU 10.2.0 -- The ASM compiler identification is GNU -- Found assembler: /mnt/data/opt/riscv/bin/riscv64-unknown-linux-gnu-gcc -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Check for working C compiler: /mnt/data/opt/riscv/bin/riscv64-unknown-linux-gnu-gcc - skipped -- Detecting C compile features -- Detecting C compile features - done -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Check for working CXX compiler: /mnt/data/opt/riscv/bin/riscv64-unknown-linux-gnu-g++ - skipped -- Detecting CXX compile features -- Detecting CXX compile features - done -- Found elfloader-tool: /mnt/data/sel4test/tools/seL4/elfloader-tool -- /mnt/data/sel4test/build/kernel/gen_headers/plat/machine/devices_gen.h is out of date. Regenerating... -- CPIO test cpio_reproducible_flag PASSED -- Found musllibc: /mnt/data/sel4test/projects/musllibc -- Found util_libs: /mnt/data/sel4test/projects/util_libs -- Found seL4_libs: /mnt/data/sel4test/projects/seL4_libs -- Found sel4_projects_libs: /mnt/data/sel4test/projects/sel4_projects_libs -- Found sel4runtime: /mnt/data/sel4test/projects/sel4runtime -- Performing Test compiler_arch_test -- Performing Test compiler_arch_test - Success -- libmuslc architecture: 'riscv' (from KernelSel4Arch 'riscv64') -- Detecting cached version of: musllibc -- Found Git: /usr/bin/git (found version "2.25.1") -- Not found cache entry for musllibc - will build from source -- Found PythonInterp: /usr/bin/python (found version "2.7.18") CMake Warning (dev) at /home/user/.local/lib/python3.8/site-packages/cmake/data/share/cmake-3.22/Modules/FindPackageHandleStandardArgs.cmake:438 (message): The package name passed to `find_package_handle_standard_args` (NANOPB) does not match the name of the calling package (Nanopb). This can lead to problems in calling code that expects `find_package` result variables (e.g., `_FOUND`) to follow a certain pattern. Call Stack (most recent call first): /mnt/data/sel4test/tools/nanopb/extra/FindNanopb.cmake:340 (FIND_PACKAGE_HANDLE_STANDARD_ARGS) /mnt/data/sel4test/tools/seL4/cmake-tool/helpers/nanopb.cmake:29 (find_package) /mnt/data/sel4test/projects/sel4_projects_libs/libsel4nanopb/CMakeLists.txt:11 (include) This warning is for project developers. Use -Wno-dev to suppress it. -- Found NANOPB: /mnt/data/sel4test/tools/nanopb -- Configuring done -- Generating done -- Build files have been written to: /mnt/data/sel4test/build user@user-KVM:/mnt/data/sel4test/build$ ninja [42/267] Building ASM object kernel/CMakeFiles/kernel.elf.dir/src/arch/riscv/head.S.obj FAILED: kernel/CMakeFiles/kernel.elf.dir/src/arch/riscv/head.S.obj /usr/bin/ccache /mnt/data/opt/riscv/bin/riscv64-unknown-linux-gnu-gcc --sysroot=/mnt/data/sel4test/build -I/mnt/data/sel4test/kernel/include/plat/default -I/mnt/data/sel4test/kernel/include -I/mnt/data/sel4test/kernel/include/64 -I/mnt/data/sel4test/kernel/include/arch/riscv -I/mnt/data/sel4test/kernel/include/arch/riscv/arch/64 -I/mnt/data/sel4test/kernel/include/plat/spike -I/mnt/data/sel4test/kernel/include/plat/spike/plat/64 -I/mnt/data/sel4test/kernel/libsel4/include -I/mnt/data/sel4test/kernel/libsel4/arch_include/riscv -I/mnt/data/sel4test/kernel/libsel4/sel4_arch_include/riscv64 -I/mnt/data/sel4test/kernel/libsel4/sel4_plat_include/spike -I/mnt/data/sel4test/kernel/libsel4/mode_include/64 -I/mnt/data/sel4test/build/kernel/gen_config -I/mnt/data/sel4test/build/kernel/autoconf -I/mnt/data/sel4test/build/kernel/gen_headers -I/mnt/data/sel4test/build/kernel/generated -march=rv64imac -mabi=lp64 -D__KERNEL_64__ -O2 -g -DNDEBUG -nostdinc -nostdlib -O2 -DHAVE_AUTOCONF -DDEBUG -g -ggdb -mcmodel=medany -fno-pic -fno-pie -fno-stack-protector -fno-asynchronous-unwind-tables -std=c99 -Wall -Werror -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs -Wmissing-declarations -Wundef -Wpointer-arith -Wno-nonnull -ffreestanding -MD -MT kernel/CMakeFiles/kernel.elf.dir/src/arch/riscv/head.S.obj -MF kernel/CMakeFiles/kernel.elf.dir/src/arch/riscv/head.S.obj.d -o kernel/CMakeFiles/kernel.elf.dir/src/arch/riscv/head.S.obj -c /mnt/data/sel4test/kernel/src/arch/riscv/head.S /mnt/data/sel4test/kernel/src/arch/riscv/head.S: Assembler messages: /mnt/data/sel4test/kernel/src/arch/riscv/head.S:24: Error: unrecognized opcode `fence.i' /mnt/data/sel4test/kernel/src/arch/riscv/head.S:31: Error: unrecognized opcode `csrw sscratch,x0' [44/267] Invoking muslc build system /mnt/data/sel4test/projects/musllibc/src/unistd/getcwd.c: In function 'getcwd': cc1: warning: function may return address of local variable [-Wreturn-local-addr] /mnt/data/sel4test/projects/musllibc/src/unistd/getcwd.c:9:7: note: declared here 9 | char tmp[PATH_MAX]; | ^~~ ninja: build stopped: subcommand failed. I tried riscv-gcc 10.2.0 and 11.1.0 with the same results. $ riscv64-unknown-linux-gnu-gcc --version riscv64-unknown-linux-gnu-gcc (gca312387ab1) 10.2.0 Copyright (C) 2020 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Is there some extension I need to add to get this working? Where do I do that?

2 2

答复: Report "Failed to touch ram region" error using virtio_console when assigned for Arm-VM more than 3G memory
by Han JingLong 韩景龙 12 Apr '22

12 Apr '22

Hi The root cause of this problem has been found, when Guest OS do the virtio console driver probe, if virtqueue's desc addr allocated by alloc_pages_exact() in the setup_vq() function is >= 0x100000000 (it is common when the memory of VM allocated exceeds 3G), at first It will be shifted right 12 bits by Guest OS(turn into a value >= 0x100000), and then use iowrite32(iobase + VIRTIO_PCI_QUEUE_PFN) to notify Host, after unsigned int type data be shifted left 12 bits by Host, the higest bits 0x1 of virtqueue's desc addr will be lost. I have submitted a PR for the amendment, waiting for the review and merge into the main branch. https://github.com/seL4/seL4_projects_libs/pull/43 BR. Allen 发件人: Han JingLong 韩景龙发送时间: 2022年3月21日 20:27 收件人: 'devel(a)sel4.systems' <devel(a)sel4.systems> 主题: Report "Failed to touch ram region" error using virtio_console when assigned for Arm-VM more than 3G memory Hi I had make virtio_console work well on my environment(armv8, RAM is 8G) based on vm_multi with Linux Guest OS(512M) and Android Guest OS(<= 3G) But I meet an error(vm_ram_touch@guest_ram.c:157<mailto:vm_ram_touch@guest_ram.c:157> Failed to touch ram region: Not registered RAM region) when assign for a VM(Android Guest OS) more than 3G memory. 1. Some logs are added for debugging this issue： +++ b/seL4_projects_libs/libsel4vmmplatsupport/src/drivers/virtio_emul.c @@ -86,6 +86,7 @@ static int emul_io_out(virtio_emul_t *emul, unsigned int offset, unsigned int si assert(size == 4); int queue = emul->virtq.queue; emul->virtq.queue_pfn[queue] = value; + printf("[hjl] queue_size:%d desc:%p\n", emul->virtq.queue_size[queue], (void *)(uintptr_t)(value << 12)); vring_init(&emul->virtq.vring[queue], emul->virtq.queue_size[queue], (void *)(uintptr_t)(value << 12), VIRTIO_PCI_VRING_ALIGN); break; +++ b/seL4_projects_libs/libsel4vmmplatsupport/src/drivers/virtio_emul_helpers.c @@ -25,10 +25,43 @@ static int write_guest_mem(vm_t *vm, uintptr_t phys, void *vaddr, size_t size, s int vm_guest_write_mem(vm_t *vm, void *data, uintptr_t address, size_t size) { + bool is_inram = false; + vm_mem_t *guest_memory = &vm->mem; + for (int i = 0; i < guest_memory->num_ram_regions; i++) { + if (guest_memory->ram_regions[i].start <= address && + guest_memory->ram_regions[i].start + guest_memory->ram_regions[i].size >= address + size) { + /* We are within a ram region*/ + is_inram = true; + } + } + + if (!is_inram) { + printf("[hjl] write mem addr:%p size:0x%lx\n", address, size); + for (int index = 0; index < guest_memory->num_ram_regions; index++) { + printf("[hjl] write mem ram_regions start:%p size:0x%lx\n", guest_memory->ram_regions[index].start, guest_memory->ram_regions[index].size); + } + } + return vm_ram_touch(vm, address, size, write_guest_mem, data); } int vm_guest_read_mem(vm_t *vm, void *data, uintptr_t address, size_t size) { + bool is_inram = false; + vm_mem_t *guest_memory = &vm->mem; + for (int i = 0; i < guest_memory->num_ram_regions; i++) { + if (guest_memory->ram_regions[i].start <= address && + guest_memory->ram_regions[i].start + guest_memory->ram_regions[i].size >= address + size) { + /* We are within a ram region*/ + is_inram = true; + } + } + + if (!is_inram) { + printf("[hjl] read mem addr:%p size:0x%lx\n", address, size); + for (int index = 0; index < guest_memory->num_ram_regions; index++) { + printf("[hjl] read mem ram_regions start:%p size:0x%lx\n", guest_memory->ram_regions[index].start, guest_memory->ram_regions[index].size); + } + } return vm_ram_touch(vm, address, size, read_guest_mem, data); } 2. The detailed log is as follows: [hjl] queue_size:128 desc:0x8eb6000 [hjl] queue_size:128 desc:0x8eb8000 [hjl] read mem addr:0x8eb8802 size:0x2 [hjl] read mem ram_regions start:0x80000000 size:0x80000 [hjl] read mem ram_regions start:0x80080000 size:0x17cda00 [hjl] read mem ram_regions start:0x8184da00 size:0xa5b2600 [hjl] read mem ram_regions start:0x8be00000 size:0x83ae98 [hjl] read mem ram_regions start:0x8c63ae98 size:0x29c5168 [hjl] read mem ram_regions start:0x8f000000 size:0x26d35 [hjl] read mem ram_regions start:0x8f026d35 size:0xc0fd92cb vm_ram_touch@guest_ram.c:157<mailto:vm_ram_touch@guest_ram.c:157> Failed to touch ram region: Not registered RAM region 3. devices.camkes configuration reference is as follows: #define VM1_RAM_BASE 0x80000000 #define VM1_RAM_SIZE 0xD0000000 #define VM1_DTB_ADDR 0x8F000000 //VM1_RAM_BASE + 0xF000000 #define VM1_INITRD_ADDR 0x8BE00000 //VM1_DTB_ADDR - VM1_INITRD_MAX_SIZE vm1.untyped_mmios = [ "0x80000000:28", // RAM "0x90000000:28", // RAM "0xa0000000:28", // RAM "0xb0000000:28", // RAM "0xc0000000:28", // RAM "0xd0000000:28", // RAM "0xe0000000:28", // RAM "0xf0000000:28", // RAM "0x100000000:28", // RAM "0x110000000:28", // RAM "0x120000000:28", // RAM "0x130000000:28", // RAM "0x140000000:28", // RAM /* "0x150000000:28", // RAM "0x160000000:28", // RAM "0x170000000:28", // RAM "0x180000000:28", // RAM "0x190000000:28", // RAM "0x1a0000000:28", // RAM "0x1b0000000:28", // RAM */ ]; 4. Present situation: At present, I tracked and found that When the Guest OS's virtio_console driver do the probe, it created the vring and iowrite to notify VMM of the virtqueue desc 's physical address in setup_vq() /* create the vring */ static void *vring_alloc_queue(struct virtio_device *vdev, size_t size, dma_addr_t *dma_handle, gfp_t flag) { ...... void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag); if (queue) { phys_addr_t phys_addr = virt_to_phys(queue); *dma_handle = (dma_addr_t)phys_addr; /* activate the queue */ iowrite32(virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); I'm very confused why is the physical memory allocated for virtqueue desc not within the effective memory range of VM when assign the memory to it exceeds 3G? BR. Allen 邮件免责申明 Email Disclaimer 本邮件仅供本邮件指定收件人使用，其所载内容可能因含有保密信息或其它原因而不得披露。除本公司及本邮件指定收件人外，任何人不得公开、传播、分发、复制、印刷或使用本邮件之任何部分或其所载之任何内容。如您误收到本邮件，请立即通知本公司，并将原始邮件、附件及其所有复本从系统中删除，切勿使用。 This email is for the use of the designated receivers only，and the content is not allowed to be disclosed due to the confidential information or other reasons. Except for the Company and the designated receivers of this email, no one shall disclose, disseminate, distribute, copy, print or use any part of this email or any content contained therein. If you receive this email by mistake, please notify the Company immediately, and delete the original email, attachments and all copies from the system. Do not use it. 网络通信可能含有计算机病毒或其它缺陷，可能无法准确和/或及时送达其它系统，亦可能受阻而不为本公司或本邮件指定收件人所知。本公司对此类错误或遗漏以及任何因使用本邮件而引致之任何损失概不承担责任。 Network communication may contain computer viruses or other defects, which may not be delivered to other systems accurately and / or in time, or may be blocked by the Company or the designated receivers of this email. The Company shall not be liable for such errors or omissions and for any loss arising from this email. 本邮件所载任何内容仅作为业务层面交流与参考，除非明确说明，本公司不对邮件所载内容之准确性、完整性或公平性等承担任何法律责任。 Any contents contained in this email are only for the purpose of business communication and reference only. Unless explicitly stated otherwise, the Company shall not assume any legal responsibility for the accuracy, completeness or fairness of the content contained in the email. 本邮件指定收件人应特别注意：本邮件所载任何内容不构成本公司对本邮件指定收件人和/或其所属商业实体的任何要约、要约邀请或承诺，任何权利义务皆以双方签字盖章的书面文件为准。除经本公司以签字盖章的书面文件确认外，收件人和/或其所属商业实体不得以本邮件所载任何内容作为其向本公司主张任何权利或利益的正式依据。 The designated receivers should pay special attention to the fact that nothing contained in this email shall constitute an offer, invitation or acceptance by the Company to the designated receivers of this email and/or its affiliated business entities, and any rights and obligations are subject to the written documents signed and sealed by both parties. Except from the written document signed ,sealed and confirmed by the Company, the receivers and / or its affiliated business entity shall not rely on anything contained in this email as the formal basis for claiming any rights or interests to the Company.

1 0

Combatting spam
by David Barrass 12 Apr '22

12 Apr '22

Hi Peter, Thank you for raising this issue - it is an annoying distraction. The general standard of the list is very high as one would expect and it is a shame to see this kind of behaviour polluting the discussions. I am very happy to have to earn a privilege to post and am happy for anything I post to be moderated. I would welcome any proposition to keep spammers off the list whilst keeping it open but I don't think any solution should impose additional burdens on the moderators. I think that this warrants a bit of thought and will give this some consideration. Your proposal sounds good and I support it. In the meantime thank you and many thanks to all the team who make this happen. I find the work on seL4 very valuable and relevant. best regards to all, David

1 0

Combatting spam on this list
by Peter Chubb 12 Apr '22

12 Apr '22

Hi Folks, We're trying hard to avoid spam coming through this list. In particular we moderate all emails coming from non-members, and only let through on-topic postings. Recently, however, we've had some people join the list, and then posting spam. I'm proposing that the first post a person makes will always be moderated; and we'll turn off the moderation after the first on-topic posting. Anyone who posts spam will have that address marked as discard immediately. This means that *all* next posts will be moderated until I or one of the other moderators lets them through, because I'll be changing the default processing. Comments? I'd rather keep things as open as possible, but spammers are making it hard. Peter C -- Dr Peter Chubb https://trustworthy.systems/ Trustworthy Systems Group CSE, UNSW Core hours: Mon 8am-3pm; Wed: 8am-5pm; Fri 8am-12pm.

1 0

RFC 10
by Gerwin Klein 11 Apr '22

11 Apr '22

This is a last call for comments for RFC-10 before the TSC votes on it this week: https://sel4.atlassian.net/browse/RFC-10 The RFC is about consolidating AArch64 page table objects and has been uncontroversial so far, just wanted to make sure people are aware of it. Cheers, Gerwin

2 1

Does the lastest master branch support gic v3 virtulization?
by wtliang785 10 Apr '22

10 Apr '22

hello devel, We want to use Sel4 in our project, but the gic version is v3. I know sel4 kernel 12.1.0 version does not support v3 virtuliazation. My question is that what is the status for supporting the v3 virtulization in lastest sel4 kernel master branch? Does the lastest master branch support gic v3 virtulization? thank you Peter Wang

2 1

capDL-tool fix for empty CNode slots
by Sam Leffler 07 Apr '22

07 Apr '22

If you generate capdl for a CNode with empty slots, capDL-tool incorrectly calculates CDL_CapMap::num because it uses Map.size which doesn't include empty slots. The right way to calculate "num" is by taking the max of the key values +1. diff --git a/capDL-tool/CapDL/PrintC.hs b/capDL-tool/CapDL/PrintC.hs index ec0eda9..b4a2cbb 100644 --- a/capDL-tool/CapDL/PrintC.hs +++ b/capDL-tool/CapDL/PrintC.hs @@ -224,7 +224,7 @@ memberSlots objs obj_id slots irqNode cdt ms = showSlots objs obj_id (Map.toList slots) irqNode cdt ms +++ "}," where - slot_count = Map.size slots + slot_count = if Map.null slots then 0 else (fst $ Map.findMax slots) + 1 printInit :: [Word] -> String printInit argv = -Sam

2 3

Interrupt handling - General Purpose Timer
by JENKINSON Mark 07 Apr '22

07 Apr '22

Hi seL4 Devel, We are trying to use the General Purpose Timer1 for our i.MX8MQ-based board within a simple CAmkES app. GPT1 is initialising and starting OK, but the interrupt handler for handling rollover is not being triggered. Through instrumenting the code with printf's, the GPT initialisation looks reasonable, and the expected rollover interrupt is being generated and seen within handleInterrupt(); however, the interrupt handler routine that has been registered is not being called. I'm hoping that someone can give me some ideas where to investigate next please? A few more details: From gpt_init() (in util_libs/libplatsupport/src/mach/imx/gpt.c), instrumentation within allocate_irq_callback() confirms that, for: gpt->irq_id = ps_irq_register(&gpt->io_ops.irq_ops, irq, gpt_handle_irq, gpt); our values are: irq->type = 3; // PS_INTERRUPT irq->irq.number = 87 (0x57); // 55 (0x37) + 32 = 87 (0x57) which agrees with the GPT1 entry from our dts file (when combined with the offset of 32, which I've seen explained elsewhere): gpt@302d0000 {... reg = < 0x302d0000 0x10000 >; interrupts = < 0x00 0x37 0x04 >;... And gpt_handle_irq() is registered as the interrupt handler, which resets the rollover flag and manages the counter's high_bits variable. Resulting from this call to ps_irq_register(), gpt->irq_id = 27 (0x1b), although I'm not sure of the significance of this irq_id value. Our test app starts GPT1. After ~3 mins, the timer rolls over, as expected. Instrumentation in handleInterrupt(irq) is triggered with: irq = 87 (0x57); // as expected, the GPT1 rollover interrupt However, gpt_handle_irq() is never called, despite being associated with irq 87 back in the ps_irq_register() call. Instrumentation in handleInterrupt() shows that the IRQSignal case is executed and sendSignal() is called. Within sendSignal, the NtfnState_Idle case is executed, calling ntfn_set_active(ntfnPtr, badge), with badge = 1. I stop tracking the flow there, but pick up again that ackInterrupt() is visited with irq = 87 (0x57). Everything looks in order (the right interrupt is generated at the right time and is detected) except gpt_handle_irq() is not called. The timer app keeps ticking away, but without the rollover management, time ends up skipping. Thanks for your help, Mark. This message contains information that may be privileged or confidential and is the property of the Capgemini Group. It is intended only for the person to whom it is addressed. If you are not the intended recipient, you are not authorized to read, print, retain, copy, disseminate, distribute, or use this message or any part thereof. If you receive this message in error, please notify the sender immediately and delete all copies of this message.

1 0

OpenPower/PowerPC/ppc64le port: major concerns and obstacles
by Isaac Beckett 06 Apr '22

06 Apr '22

Hello seL4 devel! Recently I was on the developer hangout meeting and brought up a ppc port. Interest seemed low, and some even called ppc a “niche” architecture which seems unfair. There was also the much more concrete concerns of funding and overall maintenance. I believe an PPC port would be very valuable, and I plan to do a whole essay/write up of some sort, but I am also not the most familiar with the technical challenges, and could use more information on those. I do think there is definitely people who would want to run seL4 on PowerPC platforms. PowerPC is one of the few ISAs that has existing, modern hardware without closed-source binary blobs, which I believe pose a real threat to the trustworthiness of the hardware seL4 is currently capable of running on.

2 1

A way to reclaim initial thread resources
by Marcin Witkowski 06 Apr '22

06 Apr '22

Hey, I am currently looking for a way to reclaim resources allocated by kernel for the rootserver thread, i.e. memory for CNode, TCB, BootInfo, etc. My current approach looks like this: * in rootserver instead of calling seL4_TCB_Suspend, call custom syscall seL4_ReclaimRootserverResources. This sycall as parameters takes CNode and slot no. after which kernel should be able to freely write new caps. This CNode is main CNode of some component initialized by the rootserver. * implmenetation of this syscall then suspends initial thread, schedules new thread, revokes most of rootserver's resources, notably TCB, BootInfo, IPCBuffer, VSpace and CNode. Then for those now free memory regions new untyped capabilities are created, with the same sizes as the original objects. Lastly, new capabilities are written to subsequent slots in CNode a'la boot.c, so with null MDBNode; mdbRevocable and mdbFirstBadged set to true. This solution has couple of problems. First and foremost, it requires creating additional syscall to handle this. Secondly, even though the component _technically_ has access to this newly created capabilities, it doesn't know where they are, or how big they are. This could be partially band-aided by hardcoding this information in relevant component, but that is far from elegant. This component also recives rest of the untyped memory from rootserver, including bootinfo entries about this memory specification, so that renders solution with hardcoding spec even worse. Last but not least, before the seL4_ReclaimRootserverResources is called, all the components are resumed using seL4_TCB_Resume as part of rootserver's work, so there could be race-condition between calling reclaiming syscall, and component initialization (although I am not 100% sure about that part) Is there maybe a better way to do it, and I am doing it all round? The perfect solution would be to somehow extend bootinfo and/or remaining untypeds that were given by the kernel to the rootserver.

2 3