Devel September 2015

devel@sel4.systems

15 participants
16 discussions

IA32 syscall bindings
by Norman Feske 26 Aug '16

26 Aug '16

Dear seL4 developers, first, I'd like to thank you for publishing seL4 under GPL. I am very happy that I can finally get my hands dirty with working with the kernel of your group. :-) Currently, I am taking the first baby steps to bring the Genode OS framework (http://genode.org) to seL4. For reference, I am using the experimental branch. The first smallish issue I stumbled upon stems from the fact that Genode is written in C++. By compiling the seL4 syscall bindings with a C++ compiler, I got the following error: error: inconsistent operand constraints in an ‘asm’ It can be reproduced by putting the following code snippet into a cc file and compiling it with 'g++ -m32 -c' (tested with the Genode tool chain as well as with GCC 4.8.1): typedef enum { seL4_SysDebugPutChar = -9, _enum_pad_seL4_Syscall_ID = (1U << ((sizeof(int)*8) - 1)) } seL4_Syscall_ID; void seL4_DebugPutChar(char c) { asm volatile ( "pushl %%ebp \n" "movl %%esp, %%ecx \n" "leal 1f, %%edx \n" "1: \n" "sysenter \n" "popl %%ebp \n" : : "a" (seL4_SysDebugPutChar), "b" (c) : "%ecx", "%edx", "%esi", "%edi", "memory" ); } When compiling the same code snippet with 'gcc' instead of 'g++', everything is fine. It turns out that the C++ compiler does not like the enum value to be specified as input argument. I found the following ways to circumvent this problem: * Changing the enum value 'SysDebugPutChar' to a positive value, * Removing the definition of '_enum_pad_seL4_Syscall_ID', * Casting 'seL4_SysDebugPutChar' to an integer: : "a" ((int)seL4_SysDebugPutChar), In any case, I seem to have to change the bindings. Do you see a way around it? If not, would you consider one of the solutions above for the seL4 headers? On another note, I noticed that the bindings use the EBX register. Unfortunately, this makes it impossible to compile seL4 userland software as position-independent code (PIC). E.g., when compiling the above code snippet via 'g++ -m32 -fPIC -c', the following error occurs: error: inconsistent operand constraints in an ‘asm’ However, PIC is required in order to use shared libraries. The solution would be to not use EBX to pass arguments to the 'asm' statements, save EBX on the stack prior moving the respective kernel argument to the register, and, of course, restoring it after sysenter returns. Before I start changing the bindings, I'd like to know: is there anyone else working on the same problem? Would you be open to accept a change of the bindings to become PIC compliant on the costs of a few added instructions? Or do you have another suggestion how I should go about it? Best regards Norman -- Dr.-Ing. Norman Feske Genode Labs http://www.genode-labs.com · http://genode.org Genode Labs GmbH · Amtsgericht Dresden · HRB 28424 · Sitz Dresden Geschäftsführer: Dr.-Ing. Norman Feske, Christian Helmuth

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haskell on sel4
by Tim Newsham 05 Dec '15

05 Dec '15

I just noticed the web page says "we have Haskell sort-of running on seL4 (thanks or friends from Galois for their help), should be released in the near future" This is great news. Are you able to share any details such as when any of this will be public, what the porting strategy was (is this similar to HalVM?), what dependencies haskell compiled code requires, if there are sel4 bindings, etc? Tim

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Camkes MMIO Driver Failed to find device frame
by Jeff Hieb 03 Oct '15

03 Oct '15

I am working on a UART device driver in camkes for AM335x. When I load the image on the board I get this error: Creating object frame_drv_group_bin_42 in slot 596, from untyped 1f6... device frame, paddr = 0x48022000, size = 12 bits capDL-loader :: << Error: Failed to find device frame at paddr = 0x48022000 >> I am reasonably confident the address is correct, (https://github.com/seL4/libplatsupport/blob/master/plat_include/am335x/plat…) Looking at the source It seems capDL-Loader wants to find this device frame in bootinfo https://github.com/seL4/capdl-loader-app/blob/master/src/main.c#L731 Any help on how capDL-loader builds bootinfo would be appreciated. Jeff -- Jeffrey L. Hieb Department of Engineering Fundamentals University of Louisville Louisville Kentucky 40292 (502) 852 0465

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We're hiring!
by Gernot Heiser 29 Sep '15

29 Sep '15

Want to be part of the seL4 team and be *paid* for having fun? We’re hiring: - proof engineers: https://ssrg.nicta.com.au/jobs/proof-engineers2015 - OS engineers: https://ssrg.nicta.com.au/jobs/OS-engineers2015 - researchers/postdocs: https://ssrg.nicta.com.au/jobs/OS-researchers2015 Gernot ________________________________ The information in this e-mail may be confidential and subject to legal professional privilege and/or copyright. National ICT Australia Limited accepts no liability for any damage caused by this email or its attachments.

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libsel4cspace and IPC
by Will Korteland 27 Sep '15

27 Sep '15

Hi, I'm trying to implement a "create endpoint" syscall as a continuation of my AOS project last year. I'm using the following code to create and endpoint in the current threads's cspace (using libsel4cspace): https://gist.github.com/anonymous/8294aa47ad351e4d4066 When this code runs, seL4 prints the following during the cspace_ut_retype_addr call: <<seL4 [decodeUntypedInvocation/128 Tffeead00 @b330]: Untyped Retype: Invalid destination address.>> This error comes from inside libsel4cspace, specifically where it calls seL4_Untyped_RetypeAtOffset(). I've read the libsel4cspace documentation and enabled CSPACE_DEBUG, but nothing from the output looks amiss (I'm not an expert though, and I can post the relevant debug output). Have I done anything wrong in the code above? Thanks, - Will

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How to modify timer server in refos
by ぷ风过无痕?? 27 Sep '15

27 Sep '15

I want to transplant the Refos into the ZYNQ board,Now everything is ok,except the timer server. Could you give me some advices about how to modify timer server's file device_timer.c . ------------------ Original ------------------ From: "devel-request";<devel-request(a)sel4.systems>; Date: Thu, Sep 24, 2015 10:00 AM To: "devel"<devel(a)sel4.systems>; Subject: Devel Digest, Vol 16, Issue 12 Send Devel mailing list submissions to devel(a)sel4.systems To subscribe or unsubscribe via the World Wide Web, visit https://sel4.systems/lists/listinfo/devel or, via email, send a message with subject or body 'help' to devel-request(a)sel4.systems You can reach the person managing the list at devel-owner(a)sel4.systems When replying, please edit your Subject line so it is more specific than "Re: Contents of Devel digest..." Today's Topics: 1. Reminder: Developers Day registration closes Monday (Gernot Heiser) ---------------------------------------------------------------------- Message: 1 Date: Wed, 23 Sep 2015 05:58:01 +0000 From: Gernot Heiser <gernot(a)nicta.com.au> To: seL4 <devel(a)sel4.systems> Subject: [seL4] Reminder: Developers Day registration closes Monday Message-ID: <FD16E4F0-FD7A-494C-9432-AF1C4903E750(a)nicta.com.au> Content-Type: text/plain; charset="us-ascii" Details at https://sel4.systems/Community/Devdays/ Gernot ________________________________ The information in this e-mail may be confidential and subject to legal professional privilege and/or copyright. National ICT Australia Limited accepts no liability for any damage caused by this email or its attachments. ------------------------------ Subject: Digest Footer _______________________________________________ Devel mailing list Devel(a)sel4.systems https://sel4.systems/lists/listinfo/devel ------------------------------ End of Devel Digest, Vol 16, Issue 12 *************************************

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Reminder: Developers Day registration closes Monday
by Gernot Heiser 23 Sep '15

23 Sep '15

Details at https://sel4.systems/Community/Devdays/ Gernot ________________________________ The information in this e-mail may be confidential and subject to legal professional privilege and/or copyright. National ICT Australia Limited accepts no liability for any damage caused by this email or its attachments.

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Caught cap fault in send phase at address 0x0
by Andrew Shruhan 22 Sep '15

22 Sep '15

Hello, I am attempting to create a simple program opening up a serial port on the Sabrelight. Attached is the source code and below is the console output. On other sel4 blogs with this problem uboot may have been the issue. I have used the u-boot as discribed on the supported hardware->sabrelight page with the same outcome. Any help would be appreciated. Thanks, U-Boot 2009.08-dirty (Sep 17 2015 - 14:58:04) CPU: Freescale i.MX6 family TO1.2 at 792 MHz Temperature: 36 C, calibration data 0x56a4bc7d mx6q pll1: 792MHz mx6q pll2: 528MHz mx6q pll3: 480MHz mx6q pll8: 50MHz ipg clock : 66000000Hz ipg per clock : 66000000Hz uart clock : 80000000Hz cspi clock : 60000000Hz ahb clock : 132000000Hz axi clock : 264000000Hz emi_slow clock: 132000000Hz ddr clock : 528000000Hz usdhc1 clock : 198000000Hz usdhc2 clock : 198000000Hz usdhc3 clock : 198000000Hz usdhc4 clock : 198000000Hz nfc clock : 24000000Hz Board: MX6Q-SABRELITE:[ POR] Boot Device: I2C I2C: ready DRAM: 1 GB MMC: FSL_USDHC: 0,FSL_USDHC: 1 JEDEC ID: 0xbf:0x25:0x41 Reading SPI NOR flash 0xc0000 [0x2000 bytes] -> ram 0x276009b8 SUCCESS *** Warning - bad CRC, using default environment In: serial Out: serial Err: serial Net: got MAC address from IIM: 00:19:b8:01:fd:6d FEC0 [PRIME] Hit any key to stop autoboot: 0 mmc1 is current device -- Trying fat on SD 1, partition 1 reading sel4-image 344564 bytes read ## Starting application at 0x20000000 ... ELF-loader started on CPU: ARM Ltd. Cortex-A9 r2p10 paddr=[20000000..2004c01f] ELF-loading image 'kernel' paddr=[10000000..10031fff] vaddr=[e0000000..e0031fff] virt_entry=e0000000 ELF-loading image 'hello-1' paddr=[10032000..1003ffff] vaddr=[8000..15fff] virt_entry=803c Enabling MMU and paging Jumping to kernel-image entry point... Bootstrapping kernel Caught cap fault in send phase at address 0x0 while trying to handle: vm fault on data at address 0x0 with status 0x7 in thread 0xffdfd900 "rootserver" at address 0x804 -- -Andrew Andrew P. Shruhan Research and Development Engineer III DocBox, Inc. 320 Nevada St Newton MA, 02460 Work: 857-598-2819 ext. 117 www.docboxmed.com <http://www.docboxinc.com/>

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Question about upstream
by Harish Pillay 9v1hp 20 Sep '15

20 Sep '15

Hi. I came across seL4 yesterday and have not spent too much time on it. I have not found anything specific to my question in the FAQ yet, so I am posing it here: has the work done by seL4 been accepted upstream? If not, any reason why it has not been accepted yet? Thanks. Harish

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Roadmap and Developers Day announcements
by Gernot Heiser 16 Sep '15

16 Sep '15

Dear developers, Those of you who aren’t (yet) subscribed to announce(a)sel4.systems might have missed this: we announced - the seL4 roadmap: https://sel4.systems/pipermail/announce/2015/000007.html - the second Developers Day: https://sel4.systems/pipermail/announce/2015/000008.html Gernot ________________________________ The information in this e-mail may be confidential and subject to legal professional privilege and/or copyright. National ICT Australia Limited accepts no liability for any damage caused by this email or its attachments.

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Devel September 2015