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Build for x86_64 bare-metal machine
by Mincheol Sung 19 Sep '22

19 Sep '22

Hi guys, I am hanging out with L4, but couldn't find instructions/tutorials for building L4Re for an x86_64 bare-metal machine. Can you point me in the right direction? Thanks in advance. Mincheol

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NXP LX2160 Uboot Fail
by rib0327 11 Sep '22

11 Sep '22

Hi, I am currently trying to get the L4Re running on the NXP LX2160 with U-Boot. When I try to load a .uimage I get the following error message: FDT and ATAGS support not compiled in Thank you in advance for your help.

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Problem with newest Git-Version (RPi4)
by rib0327 28 Aug '22

28 Aug '22

Hello everyone, We have a question regarding the newest Kernel version available on Git (current date: 11.08.2022). We are working on an application and have come across a problem. In a previous Git version of the Kernel we had no problem building the .uimage file; however, with the newest update we found out that the .uimage file cannot be built. Here the working version (older one): Buildung local Project exampleApp [ExampleApp_Git] ... Compiling src/main.o [ExampleApp_Git] ==> Linking exampleApp [ExampleApp_Git] ==> exampleApp built [ExampleApp_Git] ==> Installing exampleApp to local build-tree Building L4Re uimage with Application exampleApp make[1]: Entering directory '/home/dev/L4Re_Git/l4' Building entry "exampleApp". Merging images: mod00: /home/dev/L4Re_Git/build-fiasco//fiasco [436kB] mod01: /home/dev/L4Re_Git/build-l4re/bin/arm64_armv8a/l4f/sigma0 [36kBBuildung local Project exampleApp [ExampleApp_Git] ... Compiling src/main.o [ExampleApp_Git] ==> Linking exampleApp [ExampleApp_Git] ==> exampleApp built [ExampleApp_Git] ==> Installing exampleApp to local build-tree Building L4Re uimage with Application exampleApp make[1]: Entering directory '/home/dev/L4Re_Git/l4' Building entry "exampleApp". Merging images: mod00: /home/dev/L4Re_Git/build-fiasco//fiasco [436kB] mod01: /home/dev/L4Re_Git/build-l4re/bin/arm64_armv8a/l4f/sigma0 [36kB] mod02: /home/dev/L4Re_Git/build-l4re/bin/arm64_armv8a/l4f/moe [226kB] mod03: /home/dev/L4Re_Git/build-l4re/bin/arm64_armv8a/l4f/l4re [117kB] mod04: /home/dev/L4Re_Git/build-l4re/bin/arm64_armv8a/l4f/exampleApp [174kB] [bootstrap] ... Generating bootstrap.ld [bootstrap] ... Compiling startup.o [bootstrap] ==> Linking bootstrap.elf [bootstrap] ==> Image post-processing bootstrap.elf [bootstrap] ==> bootstrap.elf built ==> Installing bootstrap.elf in image directory ==> Installing bootstrap_exampleApp in image directory ==> Installing bootstrap_exampleApp.elf in image directory [bootstrap] ... Generating bootstrap.raw ==> Installing bootstrap.raw in image directory ==> Installing bootstrap_exampleApp.raw in image directory [bootstrap] ... Generating bootstrap.uimage Image Name: L4 Image #3 Created: Thu Aug 11 09:11:24 2022 Image Type: AArch64 Linux Kernel Image (uncompressed) Data Size: 1099688 Bytes = 1073.91 KiB = 1.05 MiB Load Address: 01000000 Entry Point: 01000000 ==> Installing bootstrap.uimage in image directory ==> Installing bootstrap_exampleApp.uimage in image directory Image size(s) in bytes: bootstrap_exampleApp.elf: 1534296 bootstrap.raw: 1099688 bootstrap.uimage: 1099752 Start address: 0x1000000 --> Build-Nr: 3 [bootstrap] ==> Installing bootstrap.elf to local build-tree [bootstrap] ==> Installing bootstrap_exampleApp to local build-tree [bootstrap] ==> Installing bootstrap_exampleApp.elf to local build-tree make[1]: Leaving directory '/home/dev/L4Re_Git/l4' DONE - bootstrap_exampleApp.uimage copied to /tftp/! ] mod02: /home/dev/L4Re_Git/build-l4re/bin/arm64_armv8a/l4f/moe [226kB] mod03: /home/dev/L4Re_Git/build-l4re/bin/arm64_armv8a/l4f/l4re [117kB] mod04: /home/dev/L4Re_Git/build-l4re/bin/arm64_armv8a/l4f/exampleApp [174kB] [bootstrap] ... Generating bootstrap.ld [bootstrap] ... Compiling startup.o [bootstrap] ==> Linking bootstrap.elf [bootstrap] ==> Image post-processing bootstrap.elf [bootstrap] ==> bootstrap.elf built ==> Installing bootstrap.elf in image directory ==> Installing bootstrap_exampleApp in image directory ==> Installing bootstrap_exampleApp.elf in image directory [bootstrap] ... Generating bootstrap.raw ==> Installing bootstrap.raw in image directory ==> Installing bootstrap_exampleApp.raw in image directory [bootstrap] ... Generating bootstrap.uimage Image Name: L4 Image #3 Created: Thu Aug 11 09:11:24 2022 Image Type: AArch64 Linux Kernel Image (uncompressed) Data Size: 1099688 Bytes = 1073.91 KiB = 1.05 MiB Load Address: 01000000 Entry Point: 01000000 ==> Installing bootstrap.uimage in image directory ==> Installing bootstrap_exampleApp.uimage in image directory Image size(s) in bytes: bootstrap_exampleApp.elf: 1534296 bootstrap.raw: 1099688 bootstrap.uimage: 1099752 Start address: 0x1000000 --> Build-Nr: 3 [bootstrap] ==> Installing bootstrap.elf to local build-tree [bootstrap] ==> Installing bootstrap_exampleApp to local build-tree [bootstrap] ==> Installing bootstrap_exampleApp.elf to local build-tree make[1]: Leaving directory '/home/dev/L4Re_Git/l4' DONE - bootstrap_exampleApp.uimage copied to /tftp/! And now the faulty one (latest version): Buildung local Project exampleApp [ExampleApp_Git] ==> Linking exampleApp aarch64-linux-gnu-ld: cannot find ./src/main.o: No such file or directory make[1]: *** [/home/dev/L4Re_Git/l4/mk/prog.mk:125: exampleApp] Error 1 make: *** [/home/dev/L4Re_Git/l4//mk/binary.inc:159: /home/dev/L4Re_Git/build-l4re/ext-pkg/home/dev/L4Re_Dev/ExampleApp_Git/OBJ-arm64_armv8a-l4f] Error 2 Building L4Re uimage with Application exampleApp make[1]: Entering directory '/home/dev/L4Re_Git/l4' Could not find 'exampleApp' within paths /home/dev/L4Re_Git/build-fiasco/ /home/dev/L4Re_Git/build-l4re/bin/arm64_armv8a /home/dev/L4Re_Git/build-l4re/bin/arm64_armv8a/l4f /home/dev/L4Re_Git/build-l4re/lib/arm64_armv8a /home/dev/L4Re_Git/build-l4re/lib/arm64_armv8a/l4f Processing of entry exampleApp in /home/dev/L4Re_Git/l4/conf/modules.list failed! make[3]: *** No rule to make target 'processing-of-module-list-failed', needed by 'mod.make.inc'. Stop. make[2]: *** [../../../../mk/binary.inc:159: /home/dev/L4Re_Git/build-l4re/pkg/bootstrap/server/src/OBJ-arm64_armv8a] Error 2 make[1]: *** [Makefile:544: uimage] Error 2 make[1]: Leaving directory '/home/dev/L4Re_Git/l4' make: *** [Makefile:6: do-all-make-goals] Error 2 cp: cannot stat '/home/dev/L4Re_Git/build-l4re/pkg/bootstrap/server/src/OBJ-arm64_armv8a/bootstrap_exampleApp.uimage': No such file or directory DONE - bootstrap_exampleApp.uimage copied to /tftp/! This does not happen if we create the image of ‘hello’. The problem is that the main.c file in the exampleApp does not get compiled before being linked à aarch64-linux-gnu-ld: cannot find ./src/main.o: No such file or directory. Everything was added correctly in modules.list. Does it depend on the newest update or did we make a mistake somewhere? In the attachment you will also find the build_all.sh file we used to build the image and also the Makefile for exampleApp. Thank you in advance for your help. Many regards, Mauro, Ricardo

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Qemu cannot launch pre-built epi images using OVMF.fd
by 郭聪 12 Jul '22

12 Jul '22

Hi, I cannot launch those amd64 pre-built epi images with Qemu 4.2.1 on Ubuntu 20.04. All the pc images are fine. I have added the '-bios /usr/share/qemu/OVMF.fd' option. There is a warning "KERNEL: Warning: ACPI: Could not find RSDP, skip init" and then "no console will be available to OS". It seems that the first warning is from Fiasco, in fiasco/src/kern/acpi.cpp. I guess this is because the ACPI version. How can I solve this issue? Does anyone see the same problem? Thank you very much!

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How to build a bootable l4linux image
by 郭聪 04 Jul '22

04 Jul '22

Hi, I am new to l4re. I am trying to boot a l4re image on an amd64 machine. I use dd to write pre-built-images (efi.iso) to a usb stick. I got the "no suitable video mode found" error. My BIOS has only the UEFI mode. How can I solve this error? BTW, I find how to build grub2iso of modules, but I do not know how to build a efi.iso like those pre-built ones. Could you please tell me the steps to build such an image? How can I modify the grub.conf file? Thank you!

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Unresolved page faults when running l4linux-mag
by Haohui Mai 18 Apr '22

18 Apr '22

Hello, I'm trying to run the l4linux-mag example in the L4Re snapshot. It seems it will result in an unresolved page fault using the current snapshot (22.01.0): Loading: rom/ramdisk-amd64.rd INITRD: Size of RAMdisk is 4096KiB RAMdisk from 01816000 to 01c16000 [4096KiB] l4lx_thread_create: Created thread 429 (timer0) (u:b3001c00, v:00000000, sp:01557f28) WARNING: Unknown rdmsr: c0000100 at 0x212a20 WARNING: Unknown wrmsr: c0000100 at 0x212a33 WARNING: Unknown rdmsr: c0000100 at 0x212a4f WARNING: Unknown wrmsr: c0000100 at 0x212a70 Non-resolvable page fault at 3612f82, ip 302265. Page fault (non-resolved): pfa=3612f82 pc=302265 Non-resolvable page fault at 3612f82, ip 302265. Page fault (non-resolved): pfa=3612f82 pc=302265 qemu-system-x86_64: terminating on signal 2 Changing the console from ttyS0 to ttyLv0 will go a little bit further, but still result in a page fault: BUG: unable to handle page fault for address: 0000000003612f80 #PF: user write access in kernel mode #PF: error_code(0x0006) - not-present page PGD 0 P4D 0 Oops: 0006 [#1] SMP CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.0-l4-ge2ad9258b98e #2 RIP: 0028:cache_alloc_refill+0x365/0x610 Code: 54 24 24 31 db 85 d2 74 2e 49 8b 44 24 50 48 85 c0 74 11 89 df 41 0f af 7c 24 14 49 03 7d 28 ff d0 0f 1f 00 49 8b 55 20 89 d8 <88> 1c 02 83 c3 01 41 39 5c 24 24 77 d2 45 85 f6 0f 85 fd 01 00 00 RSP: 319f9f00:000000001006bca0 EFLAGS: 00000246 ORIG_RAX: 00000000000000f0 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 6db6db6db6db6db7 RDX: 0000000003612f80 RSI: 0000000000000001 RDI: 0000000000e57840 RBP: 000000000000003c R08: 00000000000194ff R09: 0000000000000002 R10: 00000000000194f8 R11: 0000000000000006 R12: 000000001001fc00 R13: 00000880000bd3f0 R14: 0000000000000400 R15: 0000000000000dc0 FS: ffffffffffffffff(0000) GS:ffffffffffffffff(0000) knlGS:ffffffffffffffff CS: 0028 DS: 0023 ES: 0023 CR0: ffffffffffffffff CR2: ffffffffffffffff CR3: ffffffffffffffff CR4: ffffffffffffffff Call Trace: ? idr_alloc_cyclic+0x52/0xb0 kmem_cache_alloc+0xc7/0xe0 __kernfs_new_node.constprop.0+0x59/0x1a0 ? vsnprintf+0x3e6/0x5b0 ? kernfs_link_sibling+0x8d/0xd0 ? kernfs_next_descendant_post+0x7d/0x90 ? kernfs_activate+0x5a/0x80 ? kernfs_add_one+0xdd/0x130 kernfs_new_node+0x1b/0x40 __kernfs_create_file+0x20/0xb0 sysfs_add_file_mode_ns+0x96/0x180 sysfs_create_file_ns+0x5d/0x90 bus_create_file+0x3f/0x60 bus_register+0x180/0x240 subsys_system_register+0x16/0x40 ? ntp_init+0x21/0x21 init_clocksource_sysfs+0xe/0x1f do_one_initcall+0x44/0x190 kernel_init_freeable+0x161/0x1ab ? rest_init+0xb0/0xb0 kernel_init+0x11/0x100 Any ideas to debug this? Your help is appreciated. Thanks, Haohui

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Where is the latest L4Linux repo?
by Haohui Mai 04 Mar '22

04 Mar '22

Greetings! I've been playing around with L4Re + L4Linux recently. I'm interested in getting the source code of L4Linux 5.13. However, it seems that the latest commit of the subversion repository (https://svn.l4re.org/repos/oc/l4linux/trunk) listed on the L4Linux website is in 2018. Since the group has just released L4Linux 5.15 recently, I'm just wondering what is the URL of the latest repository? Your help is much appreciated. Thanks, Haohui

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Unable to boot hello example.
by Ashwin Krishnakumar 05 Feb '22

05 Feb '22

Hello all, I have created this issue in the manifest repo. Issue : https://github.com/kernkonzept/manifest/issues/12 I am writing it again. I am trying to boot an AMD64 and ARM64 machine using fiasco. The Fiasco and L4 build works fine. We are able to generate the final elf also successfully. However the QEMU is unable to boot the machine. IT just freezes at startup with the comment "ROM booting". 1. Fiasco building successfully [image: image.png] 1. L4 runtime built successfully [image: Screen Shot 2022-02-04 at 4 18 24 AM] <https://user-images.githubusercontent.com/16016925/152503555-8c02af0d-1177-…> 1. Able to give a boot command. However the system requires a video card. So I moved to my Linux laptop and observed that the system boots beyond this error, but is not printing hello world. [image: Screen Shot 2022-02-04 at 4 25 57 AM] <https://user-images.githubusercontent.com/16016925/152504574-72b7b2c8-58a1-…> In my local laptop it just says booting from ROM and freezes. Is there an alternate instruction for booting examples for ARM64 and AMD64 ? Regards, -- Ashwin Krishnakumar, +15714980269 ECE Graduate Student, Virginia Tech.

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CfP: Microkernel and Component-based OS Devroom at FOSDEM 2022
by Martin Decky 06 Dec '21

06 Dec '21

Microkernel and Component-based OS Devroom at FOSDEM 2022 CALL FOR PARTICIPATION On-line version of this CfP: http://fosdem.microkernel.info/ The developers and users of several free and open source microkernel-based and component-based operating systems will meet on-line as part of FOSDEM 2022 [1] and will share a developer room. The devroom is currently looking for content in the form of talks and activities related to the area of microkernel-based, unikernel-based, component-based operating systems and similar topics. The devroom has been preliminarily scheduled to Saturday February 5th 2022. The devroom will take place during European day hours. Possible topics of the devroom include, but are not limited to: * introduction of a specific OS or framework * design of subsystems and the general architecture of an OS * languages, tools and toolchains used * enabling support for hardware (architectures, device drivers) and programming languages * development processes, debugging * maintenance, testing and release engineering * safety, security and robustness * trends and challenges * research and open questions * community and governance * use cases, experiences and status updates * best practices and lessons learned * demos This is a call for your participation. We kindly ask you to submit your proposals no later than on December 28th 2021. Please use the Pentabarf web site [2] to submit your proposals. If you already have a user account in Pentabarf, please do not create a new one. Addtionally, make sure to select the Microkernel and Component-based OS Devroom as the track when submitting your talk and include at least the following information in your proposal: * title of your talk * your full name * short abstract of your talk (one or two paragraphs) * duration of your talk (at least 20 minutes and no longer than 50 minutes) * your short bio * your photo The talks will be pre-recorded in advance in January and streamed automatically during the event. This means that you will need to complete and submit your talk recording by January 15th 2022. However, each speaker should be also present on-line just after the streaming of their talk for a live Q&A. You can specify your prefered time slot of your talk. The communication language of the devroom is English. The official devroom schedule (along with the accepted talks) will be announced on December 31st 2021 on the devroom's mailing list [3] and the speakers will be notified via e-mail. The schedule will also be published on the FOSDEM web site. For any comments, questions and suggestions (e.g. suggestions for a different type of event during the devroom), please do not hesitate to use the devroom's mailing list [3]. About the Devroom Since the first Microkernel OS Devroom at FOSDEM 2012 [4], this devroom has been a part of each following FOSDEM (with slight variations of the name). The focus gradually widened to include component-based, unikernel-based and other operating systems. By now, it has become a somewhat institutionalized tradition for the open source operating systems community and it is one of the few places where microkernel enthusiasts and people with different views on how operating systems should work meet regularly. To this date, over a dozen projects have participated in one way or another. Many of the projects face similar challenges but come up with partially different solutions. Therefore, the goal of the devroom is to bring the various projects together, let them exchange ideas, cross-pollinate and socialize. Extraordinary Circumstances in 2022 (Again) Due to the extraordinary mode of organization of FOSDEM 2022 (being an on-line event again), the devroom talks will be required to be pre-recorded in January and streamed during the event (with a live Q&A). The talk videos will be published under Creative Commons license by FOSDEM. By submitting a recorded talk, the speaker agrees to have it made available publicly indefinitively. For organizational purposes, we also need contact information of the speakers of accepted talks. Please check the official CfP page [5] of the devroom regularly. We will keep updating it as technical guidelines will be set by the FOSDEM organizers. Microkernel Dinner Sadly, it will not be possible to arrange our traditional microkernel dinner and other in-person social gatherings in Brussels this time again. However, we plan a closing event of the devroom as a loose approximation of the microkernel dinner. The details will be announced later. We encourage the on-line participats to bring their own food and beverages. About FOSDEM FOSDEM [6] is a two-day event organized by volunteers to promote the widespread use of free and open source software. FOSDEM is widely recognized as one of the best such conferences worldwide. FOSDEM covers a wide spectrum of free and open source software and hardware projects and offers a platform for people to collaborate. To this end, FOSDEM has set up developer rooms (devrooms) where teams can meet and showcase their projects. Devrooms are a place for teams to discuss, hack and publicly present latest directions, lightning talks, news and proposals. Besides developer rooms, FOSDEM also offers main tracks, lightning talks, certification exams and project stands. In recent years, FOSDEM has been hosting more than 5000 developers annually at the ULB Solbosch campus. Due to the circumstances, FOSDEM 2022 will be organized as an on-line event. The participation in FOSDEM is totally free, although the organizers gratefully accept donations and sponsorship. No registration is necessary, but attendees are expected to follow the FOSDEM's code of conduct [7]. Important Dates Recap * 2021-12-28: Deadline for talk proposal submission * 2021-12-31: Schedule published and speakers notified of acceptance * 2022-01-15: Deadline for talk pre-recoding submission * 2022-02-05: Devroom taking place on-line Contact In case of any comments, questions and suggestions, please do not hesitate to contact the devroom organizers via the devroom's mailing list [3]. The primary organizers of the devroom in 2022 are: * Sebastian Sumpf * Martin Decky Links [1] https://fosdem.org/2022/ [2] https://penta.fosdem.org/submission/FOSDEM22/ [3] https://lists.fosdem.org/listinfo/microkernel-devroom [4] https://archive.fosdem.org/2012/schedule/track/microkernel_os_devroom.html [5] http://fosdem.microkernel.info/ [6] https://fosdem.org/ [7] https://fosdem.org/2022/practical/conduct/

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Basic support for HiKey960 & SMP question
by Martin Decky 05 Oct '21

05 Oct '21

Dear L4 hackers, I have implemented a basic support for the HiKey960 board (based on the Kirin 960 SoC) [1] in Fiasco.OC and L4Re. If you are interested, please feel free to examine the code at GitHub [2]. I would be more than happy for a code review and suggestions towards potential upstream merging. The code is based on the latest L4Re base 21.07.0 snapshot. I have wanted to rebase the implementation on the latest revisions of the respective GitHub repositories, but unfortunately the current upstream Fiasco does not work for me properly even in QEMU. The implementation is very basic (fixed physical memory layout, UART support only, etc.), but seems to be working fine on the default examples. Unfortunately, I am struggling for some time with making the additional CPU cores work. I would greatly appreciate your assistance in this matter. In a nutshell, the additional 3 little cores (A53) are woken up correctly using the PSCI call (I am not tackling the 4 big A73 cores yet), but the Fiasco code livelocks in the loop around the STXR instruction in src/kern/arm/64/tramp-mp.S [3]. The STXR instruction always reports that the exclusive access to the _tramp_mp_spinlock failed despite no other accesses to the spinlock happened (confirmed using a JTAG debugger). I have checked all the usual culprits like proper virtual memory mapping attributes. I don't see any significant difference between the initialization code of Fiasco and the initialization code of other kernels that support HiKey960. I am also aware of the recent Adam's fix to the _tramp_mp_spinlock code [4], but not even that fixes the livelock issue on HiKey 960. Does anyone have any idea what might be root cause of the livelock here? Thanks in advance for any input. [1] https://www.96boards.org/product/hikey960/ [2] https://github.com/martin-decky/L4Re-HiKey960 [3] https://github.com/martin-decky/L4Re-HiKey960/blob/master/src/fiasco/src/ker n/arm/64/tramp-mp.S#L247 [4] https://github.com/kernkonzept/fiasco/commit/6bc2f7132982bc1e159abb716eb9026 71d381e9e Best regards Martin Decky

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