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Task Priority Setting
by Nourhan Mohamed 02 May '16

02 May '16

Dear L4Hackers, I have been trying to run 2 simple L4 tasks and give one of them highest scheduling priority and the other one the least. I have tried using the priority attribute in the start script as well as: scheduler = L4.Env.user_factory:create(L4.Proto.Scheduler, 0x18, 0x8) with different ranges for each of them but I don't notice any change in their runtimes. Am I missing something here? Thanks in advance, Nourhan

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Question about ARM LPAE
by li94575 07 Apr '16

07 Apr '16

hello, I want to use the ARM LPAE in Fiasco.OC, may I need to modify the start code of l4re? The board supports two DDR3 channels, and each channel supports two chip-selects. I need to use the memory device on CS0 populated for each channel. One memory rang is from 0x00000000 to 0x3fffffff, the anther is from 0x100000000 to 0x13fffffff. How can sigma0 see both of them? thank you!

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Bootstrap in real mode on x86_64: Possible?
by Maxim Baryshnikov 04 Apr '16

04 Apr '16

Hello everyone, I am trying to find some ways to port/launch Fiasco.OS into "The Jailhouse hypervisor <https://github.com/siemens/jailhouse.git>" environment using x86_64 architecture. This hypervisor does not provide any bootloader at all. It simply loads raw binary on the specified address and launches it in real mode from this address. In 'l4/pkg/bootstrap/server/src/README' I found two options described. I think it might be suitable for me. 3) bootstrap can boot from real-mode, esp. with pxelinux, i.e. it can be booted via PXE. For that it also needs include all images. This should also work with syslinux (e.g. from CDs/DVDs). (Note, grub can also read is9660 filesystems.) 4) bootstrap starts from protected mode but isn't started by a multiboot compliant loader. Also needs to include all modules. So, I started my tries from the 3th option. Following the bootstrap code, I find out that there is some piece of code for real mode bootstrapping and the defining of "REALMODE_LOADING" directive switches it on. I have tried to compile it with REALMODE_LOADING = 1 (and also with IMAGE_MODE = 1, and RML = 1), which I added in 'bootstrap/server/src/Makeconf.local' folder. Also, I commented the row with error command in Makefile.rules: |ifneq ($(REALMODE_LOADING)$(RML),00) REALMODE_LOADING := 1 #$(error Info: Default reloc needs to be 0x00100000) # And if you have done so you probably need to relink sigma0 and/or moe endif||| I admit that I did not actually understand the purpose of this block here.. I would really appreciate if someone explains it to me. Unfortunately, when I continue to make it without command mentioned above I've faced with the following compilation error: | [bootstrap] ... Compiling platform/x86_pc.o|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc: In member function ‘const char* {anonymous}::Platform_x86_1::cmdline() const’:|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc:73:26: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]|| || return (char const *)p;|| || ^|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc: In member function ‘virtual Boot_modules::Module {anonymous}::Platform_x86_multiboot::module(unsigned int, bool) const’:|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc:176:64: error: ‘mbi’ was not declared in this scope|| || l4util_mb_mod_t *mb_mod = (l4util_mb_mod_t*)(unsigned long)mbi->mods_addr;|| ||^|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc: In member function ‘virtual unsigned int {anonymous}::Platform_x86_multiboot::num_modules() const’:|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc:184:41: error: ‘mbi’ was not declared in this scope|| || unsigned num_modules() const { return mbi->mods_count; }|| || ^|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc: In member function ‘virtual void {anonymous}::Platform_x86_multiboot::reserve()’:|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc:190:43: error: ‘mbi’ was not declared in this scope|| || regions->add(Region::n((unsigned long)mbi,|| || ^|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc: In member function ‘virtual void {anonymous}::Platform_x86_multiboot::move_module(unsigned int, void*, bool)’:|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc:232:61: error: ‘mbi’ was not declared in this scope|| || l4util_mb_mod_t *mod = (l4util_mb_mod_t*)(unsigned long)mbi->mods_addr + index;|| ||^|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc: In member function ‘virtual l4util_mb_info_t* {anonymous}::Platform_x86_multiboot::construct_mbi(long unsigned int)’:|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc:249:9: error: ‘mbi’ was not declared in this scope|| || if (mbi->flags & L4UTIL_MB_CMDLINE)|| || ^|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc:253:9: error: ‘mbi’ was not declared in this scope|| || if (mbi->flags & L4UTIL_MB_VIDEO_INFO)|| || ^|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc:263:45: error: ‘mbi’ was not declared in this scope|| || total_size += sizeof(l4util_mb_mod_t) * mbi->mods_count;|| || ^|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc:345:3: warning: control reaches end of non-void function [-Wreturn-type]|| || }|| || ^|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc: In member function ‘virtual unsigned int {anonymous}::Platform_x86_multiboot::num_modules() const’:|| ||/home/coon848/projekt-git-clones/l4re-snap/src/l4/pkg/bootstrap/server/src/platform/x86_pc.cc:184:58: warning: control reaches end of non-void function [-Wreturn-type]|| || unsigned num_modules() const { return mbi->mods_count; }|| ||^|| ||/||home/coon848/projekt-git-clones/l4re-snap/src/l4/mk/binary.inc:825: recipe for target 'platform/x86_pc.o' failed| It says that problem is in 'platform/x86_pc.cc'. So, my question is, does the real mode option switch on like that or I did something wrong? How should it be done? And if it is possible to bootstrap without multiboot complaint loader in protected mode, how should it be compiled? Thank you in advance. Sincerely, Maxim Baryshnikov.

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Microkernel Meetup
by Bjoern Doebel 03 Apr '16

03 Apr '16

Hi all, it is time for another meeting of current and former microkernel enthusiasts in Dresden. I prepared a Dudle to find a suitable time: http://dudle.inf.tu-dresden.de/mks-0316/ and will let you know about a location once we settled on a date. Looking forward to your replies! Bjoern

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Can the latest L4Linux support for the ARM big.LITTLE architecture ?
by li94575 20 Mar '16

20 Mar '16

hi all, As we know, Linux has begun to support ARM big.LITTLE architecture from the 3.10 edition. Have this feature also been achieved in L4linux ? thank you!

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Booting L4Linux on Raspberry Pi 2
by Antoine DEBUT 20 Mar '16

20 Mar '16

Hello l4-hackers, Since I was able to correctly set up my l4re for the Raspberry Pi 2 thanks to Adam, I did a bunch of tests on the board with custom programs and following the examples on the l4/pkg/examples directory. Therefore, I am now struggling with the ultimate test: booting and using L4Linux. I am trying to boot a vanilla L4Linux, using the entry 'L4Linux-basic' given in the default modules.list. Upon booting, L4Linux delivers this error : [...] l4linux | List of all partitions: l4linux | 0100 4000 ram0 (driver?) l4linux | 0101 4000 ram1 (driver?) l4linux | 0102 4000 ram2 (driver?) l4linux | 0103 4000 ram3 (driver?) l4linux | 0104 4000 ram4 (driver?) l4linux | 0105 4000 ram5 (driver?) l4linux | 0106 4000 ram6 (driver?) l4linux | 0107 4000 ram7 (driver?) l4linux | 0108 4000 ram8 (driver?) l4linux | 0109 4000 ram9 (driver?) l4linux | 010a 4000 ram10 (driver?) l4linux | 010b 4000 ram11 (driver?) l4linux | 010c 4000 ram12 (driver?) l4linux | 010d 4000 ram13 (driver?) l4linux | 010e 4000 ram14 (driver?) l4linux | 010f 4000 ram15 (driver?) l4linux | No filesystem could mount root, tried: ext3 ext2 ext4 cramfs l4linux | Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(1,0) l4linux | CPU: 0 PID: 1 Comm: swapper Not tainted 4.3.0-l4 #2 l4linux | Hardware name: L4 l4linux | [<0200cb88>] (unwind_backtrace) from [<0200583c>] (show_stack+0x10/0x14) l4linux | [<0200583c>] (show_stack) from [<020627a4>] (panic+0x7c/0x1cc) l4linux | [<020627a4>] (panic) from [<02354df0>] (mount_block_root+0x25c/0x29c) l4linux | [<02354df0>] (mount_block_root) from [<023550f4>] (prepare_namespace+0x160/0x1b4) l4linux | [<023550f4>] (prepare_namespace) from [<02354a40>] (kernel_init_freeable+0x178/0x1c0) l4linux | [<02354a40>] (kernel_init_freeable) from [<0227409c>] (kernel_init+0x8/0xec) l4linux | [<0227409c>] (kernel_init) from [<02007e34>] (ret_from_fork+0x14/0x20) l4linux | [<02007e34>] (ret_from_fork) from [<00000000>] ( (null)) l4linux | ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(1,0) l4linux | ------------[ cut here ]------------ l4linux | WARNING: CPU: 0 PID: 1 at /home/adebut/Documents/L4Hyperviseur-LBNV/l4re-snapshot-2015123115/src/l4linux/arch/l4/kernel/main.c:2148 l4x_blink+0x10/0x50() l4linux | Modules linked in: l4linux | CPU: 0 PID: 1 Comm: swapper Not tainted 4.3.0-l4 #2 l4linux | Hardware name: L4 l4linux | [<0200cb88>] (unwind_backtrace) from [<0200583c>] (show_stack+0x10/0x14) l4linux | [<0200583c>] (show_stack) from [<0201dee4>] (warn_slowpath_common+0x78/0xb0) l4linux | [<0201dee4>] (warn_slowpath_common) from [<0201dfb8>] (warn_slowpath_null+0x1c/0x24) l4linux | [<0201dfb8>] (warn_slowpath_null) from [<02001af0>] (l4x_blink+0x10/0x50) l4linux | [<02001af0>] (l4x_blink) from [<0206289c>] (panic+0x174/0x1cc) l4linux | [<0206289c>] (panic) from [<02354df0>] (mount_block_root+0x25c/0x29c) l4linux | [<02354df0>] (mount_block_root) from [<023550f4>] (prepare_namespace+0x160/0x1b4) l4linux | [<023550f4>] (prepare_namespace) from [<02354a40>] (kernel_init_freeable+0x178/0x1c0) l4linux | [<02354a40>] (kernel_init_freeable) from [<0227409c>] (kernel_init+0x8/0xec) l4linux | [<0227409c>] (kernel_init) from [<02007e34>] (ret_from_fork+0x14/0x20) l4linux | [<02007e34>] (ret_from_fork) from [<00000000>] ( (null)) l4linux | ---[ end trace 5ed140c2c802ee32 ]--- l4linux | panic: going to sleep forever, bye l4linux | panic: going to sleep forever, bye I cannot find any related mail on this mailing list, and therefore must ask you for some help. Could this be a partition misconfiguration ? Or is it related to the '(driver?)' warning on the partition list ? I have attached my globalconfig.out for Fiasco and the l4lx.cfg file that I am using, built l4linux for Arm architecture and ARMv7, and is using the l4re-snapshot-2015123115 with its ramdisk associated and U-boot. Thanks in advance for your help, -- Antoine Debut EPITA 2016 - GISTRE

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Problems running example isr
by Nourhan Mohamed 20 Mar '16

20 Mar '16

Dear L4Hackers, I have a problem running the example "isr" in the pkg/examples/sys/isr folder in l4 source. It prints "isr | Press keys now, Shift-Q to exit" then It fails to detect any interrupts and just keeps waiting. My configuration is as follows, emulated using Qemu on vexpress-a15 machine: modules.list: entry isr kernel fiasco -jdb_cmd=JS -serial_esc roottask moe rom/ex_isr.cfg module ex_isr.cfg module isr module ned module l4re module keyboard.io module arm-ve.devs module io module cons arm-ve.devs: -- vim:set ft=lua: local Res = Io.Res local Hw = Io.Hw Io.hw_add_devices(function() KBD = Hw.Device(function() Property.hid = "AMBA KMI Kbd"; compatible = {"arm,pl050","arm,primecell"}; Resource.irq = Res.irq(44); Resource.regs = Res.mmio(0x1c060000, 0x1c060010); end); end) keyboard.io: local hw = Io.system_bus(); Io.add_vbus("keyboard", Io.Vi.System_bus { amba = wrap(hw:match("arm,pl050")); }) ex_isr.cfg: local L4 = require("L4"); local loader = L4.default_loader; vbus_key = loader:new_channel(); local cons = loader:new_channel(); loader:start( { caps = { cons = cons:svr() }, log = L4.Env.log, }, "rom/cons -k -a" ); L4.default_loader.log_fab = cons; loader:start( { caps = { sigma0 = L4.cast(L4.Proto.Factory,L4.Env.sigma0):create(L4.Proto.Sigma0); icu = L4.Env.icu; keyboard = vbus_key:svr(); }, l4re_dbg = L4.Dbg.Boot, log = {"IO", "magenta"}, }, "rom/io -vvv rom/arm-ve.devs rom/keyboard.io"); loader:start({ caps = { icu = L4.Env.icu; vbus = vbus_key }, log = {"isr", "cyan", "key=1"}, }, "rom/isr"); where "rom/isr" refers to the example file "isr/main.c" provided. Thank you so much Nourhan

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Fwd: 'Illegal Instruction' on L4Linux
by Alexander Tarasikov 18 Mar '16

18 Mar '16

Forwarding here just in case someone stumbles on this thread. Forgot to reply-all :( ---------- Forwarded message ---------- From: Alexander Tarasikov <alexander.tarasikov(a)gmail.com> Date: Mon, Feb 1, 2016 at 10:28 PM Subject: Re: 'Illegal Instruction' on L4Linux To: ba_f <ba_f(a)rbg.informatik.tu-darmstadt.de> On Mon, Feb 1, 2016 at 8:53 PM, ba_f <ba_f(a)rbg.informatik.tu-darmstadt.de> wrote: > Hello, > > > i have an issue with apps running on L4Linux. > > /usr/bin # ./helloWorld > Illegal instruction > > Actually, on the current l4re-snapshot-2015123115 my apps run without > problem. > But, on l4re-snapshot-2014022818 or l4re-snapshot-2014092821 the same app > don't works. > All apps say 'Illegal instruction'. > > I've built for Zynq. > > > Any idea what's wrong? You have not provided enough information. For example, how you compile Fiasco, L4Re and L4Linux. My experience with L4Re tells me you probably forgot to enable VFP/NEON in configuration options - check the menuconfig for Fiasco, L4Re and L4Linux. Most likely what happened is that the newer toolchain is by default using the "hardfloat" ABI and the compiler generates VFP/NEON instructions. If that fails, I suggest that you try debugging it yourself Therefore, there are several places you should look at: 1) First, you could try running the app under gdb. It will then print the stack trace and point to the offending instruction. 2) You could also install a SIGILL handler in your app and see what's the actual instruction causing the fault. I have an example code here - https://gist.github.com/astarasikov/9369538#file-arm-sigill-example-L71. It's actually a complicated example that patches the code at runtime. What you need to look at is at the following lines in "my_sh": # ucontext_t *uc = (ucontext_t*)data; # struct sigcontext *ctx = &(((ucontext_t*)uc)->uc_mcontext); # ctx->arm_pc; //this is the address of the instruction. You can printf it (as an unsigned integer) and decode the instruction. 3) If that fails, you could patch the invalid opcode handler in kernel to print the instruction. You should grep "arch/arm" and "arch/l4" for "SIGILL". Then, you can add the code to the trap handler. Alternatively, if you build kernel with CONFIG_DEBUG and CONFIG_DEBUG_USER, you will be able to see the stack trace and the hex dump of the instruction in the "dmesg" (or on the serial port console). > > (My project is stable on the old snapshots, that's why i try to avoid > migrating to current snapshot.) > > > > thanks, > ba_f > > _______________________________________________ > l4-hackers mailing list > l4-hackers(a)os.inf.tu-dresden.de > http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers -- Regards, Alexander -- Regards, Alexander

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L4linux IPC communication with L4re application
by Ahmed Makkawi 15 Mar '16

15 Mar '16

Hi all, I think the solution to the communication of an application on l4linux with an application on l4re would be to implement an ipc stream in the character device module in the l4linux kernel to communicate with the IPC stream on l4re application. the Problem now is l4linux modules are in C and the l4re application is in C++, is this a good idea to start searching in it or its a dead end and maybe someone would have a better idea to work on ? Ahmed Makkawi

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FYI: microkernel.info community site
by Jakub Jermář 14 Mar '16

14 Mar '16

Hello, just FYI, I have set up a simple web page[1] to promote the wider microkernel community and its goals. So far, the page comes with a brief description of the microkernel concept and an incomplete list of microkernel projects with links to each project's web. The description is made out of the first two sentences I found in the "What is XYZ" section or elsewhere on the web of the respective project. I also took the freedom to use the respective project's logo (or what I believed was the project's logo) for promoting it. I hope you will find this small web a good idea. It was inspired by a similar (though a little bit more informative) site set up by the unikernel community [2]. The sources of the [1] web are hosted on Github [3], so feel free to submit issues or PR to make the site better. Please send me a PM if there are any issues pertaining your project's cartouche that cannot be dealt with using Github. Thanks, Jakub [1] http://microkernel.info [2] http://unikernel.org/projects/ [3] https://github.com/jermar/microkernel.info

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