l4-hackers March 2016

l4-hackers@os.inf.tu-dresden.de

16 participants
13 discussions

Porting Fiasco + L4Re to Raspberry Pi 2
by Antoine DEBUT 26 Nov '17

26 Nov '17

Hello l4-hackers, I am currently working on porting the Fiasco.OC micro kernel onto the Raspberry pi 2. Therefore, I am struggling with memory mapping, and I encounter the following error when launching the default 'hello' entry: L4 Bootstrapper Build: #2 Tue Feb 23 11:57:19 CET 2016, 4.8.3 20140303 (prerelease) Scanning up to 1024 MB RAM, starting at offset 32MB Memory size is 1024MB (00000000 - 3fffffff) RAM: 0000000000000000 - 000000003fffffff: 1048576kB Total RAM: 1024MB Scanning fiasco Scanning sigma0 Scanning moe Moving up to 5 modules behind 1100000 moving module 02 { 10db000-110c4d7 } -> { 11cc000-11fd4d7 } [201944] moving module 01 { 10c9000-10da373 } -> { 11ba000-11cb373 } [70516] moving module 00 { 1043000-10c889f } -> { 1134000-11b989f } [546976] moving module 04 { 1029000-10425af } -> { 111a000-11335af } [103856] moving module 03 { 100f000-102849b } -> { 1100000-111949b } [103580] Loading fiasco Loading sigma0 Loading moe find kernel info page... found kernel info page at 0x2000 Regions of list 'regions' [ 1000, 1aff] { b00} Kern fiasco [ 2000, 92fff] { 91000} Kern fiasco [ 93000, 930eb] { ec} Root mbi_rt [ c0000, c9c33] { 9c34} Sigma0 sigma0 [ d0000, d6177] { 6178} Sigma0 sigma0 [ 140000, 16905b] { 2905c} Root moe [ 170000, 17b58b] { b58c} Root moe [ 1000000, 100e4ff] { e500} Boot bootstrap [ 1100000, 1133fff] { 34000} Root Module API Version: (87) experimental Sigma0 config ip:000c0100 sp:00000000 Roottask config ip:00140250 sp:00000000 Starting kernel fiasco at 000012b8 Non-HYP kernel detected but running in HYP mode, switching back. Hello from Startup::stage2 Assertion failed at /home/adebut/Documents/snapshotTest/l4re-snapshot-2015123115/src/kernel/fiasco/src/kern/buddy_alloc.cpp:101: (unsigned long)block >= _base Press any key to reboot. I am currently working on the latest snapshot (2015123115), with U-Boot as a bootloader, and testing on a real board (Raspberry Pi 2 model B V1.1). The entry built is the standard 'hello', and I use the ramdisk-arm.rd given in the snapshot. I did add a custom Bsp for the board, mainly based on the first Raspberry Pi except for the Base Address, that is 0x3F000000 instead of the first Pi's 0x20000000. I highly think that it is an address configuration problem, because it first happened when I did expand the RAM size to 1024MB. With further investigation, I found out that it was the kernel memory allocation that causes this error, and suspect an incorrect MMU mapping. This suspicion comes from the fact that the assertion takes the address _base (0xf0400000) and the currently allocated block (0xee100000). I did not modify any parameter in the kern/arm/mem_layout-arm.cpp file on the Fiasco directory, which provides the default ARM addressing. Maybe that's where my error comes from ? How can I correctly configure my memory mapping, besides what I already configure in the Bsp (given in attachment) ? Also, it is the first time that I am assigned for porting a system, do you have some hints, like important steps to follow ? I am pretty sure it is a newbie error, but I cannot figure it out for now :( Thanks in advance for your time, -- Antoine Debut EPITA 2016 - GISTRE

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Graphical desktop, l4con, mag
by teclis High Elf 02 Jun '17

02 Jun '17

Guten Tag, I've got the Hello app runing with fiasco and l4re in qemu, how do I get the graphical UI and console running that I see on the screen shots page? Do I need to use l4con and mag? I don't see an entry with l4con in modules.list. danke * <http://german.about.com/library/media/Audio/gutentag.wav>*

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libfs/ FUSE on L4Re
by Stark, Josef 31 May '17

31 May '17

Hello, yesterday I came across a very interesting paper titled "Porting FUSE to L4Re", accessible here: http://os.inf.tu-dresden.de/papers_ps/pester-beleg.pdf For porting FUSE, the author uses a library called "libfs" which provides filesystem request forwarding and processing, if I understood correctly. It reads as if libfs is already included in L4Re. However, I couldn't find neither FUSE nor libfs in the current L4Re snapshot. Are they by any chance publicly available somewhere else, or are both not to be published? Cheers, Josef

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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!

2 8

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

1 2

Can the latest L4Linux support for the ARM big.LITTLE architecture ?
by li94575 21 Mar '16

21 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 21 Mar '16

21 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

2 5

Problems running example isr
by Nourhan Mohamed 21 Mar '16

21 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

2 3

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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l4-hackers March 2016