August 2014 - kernelnewbies@kernelnewbies.org

Linux filesystem configuration infrastructure
by Sankar P Aug. 4, 2014

Aug. 4, 2014

Hi, I have a simple filesystem that I did for learning purpose https://github.com/psankar/simplefs Now, I would like to add a few settings to my filesystem (such as the number of blocks that should be allocated in an extent by default, maximum fragmentation score after which defrag should be automatically handled etc.) I would like to have the ability to not just set these settings, but export them to a file and restore these settings later. Is there some kind of a settings infrastructure code that is available in the linux kernel or should I be developing something specific to my filesystem ? I would also like to have some kind of validation system also as part of the settings interface. For example: If a setting can accept only ints, trying to set a string to that should be disabled, min and max values (range) for values of settings, etc. I googled and found that sysctl interface and the sysfs interfaces seem to be doing something similar. But I was not sure which to pick as the wikipedia pages were not as elaborate as I would like. So my question is: Is there a settings infrastructure provided by the linux kernel and is any filesystem (or any other kernel components) that make use of such a settings infrastrucutre ? Thanks. -- Sankar P http://psankar.blogspot.com

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How to implement a tty serial driver for RFC2217 networked serial port access devices?
by TJ Aug. 2, 2014

Aug. 2, 2014

I'm investigating how to design and write a module for RFC2217 [1] networked serial port access devices. The aim is to present /dev/ttyXXYY devices so that all user-space applications that connect to local serial ports can connect to the remote RFC2217 ports in the same way. The kernel module would act as a RFC2217 client, presenting the local system with serial TTY devices whose endpoints are on a remote network access device, e.g. the Moxa NPort 6650 [2][*]. The driver would need a configuration interface for setting the endpoint(s) for one or more access servers, possibly via sysfs. Because of the underlying TCP network link I'm not at all clear on how to implement it so I am hoping that others may have some insight on how to tackle this, in particular how to handle the network connections since they seem more appropriate for user-space rather than the kernel. For an access device with 16 ports I'd imagine presenting something like /dev/ttyNET${DEV}p${PORT}, e.g: /dev/ttyNET0p0 /dev/ttyNET0p1 /dev/ttyNET0p2 ... /dev/ttyNET0p13 /dev/ttyNET0p14 /dev/ttyNET0p15 and a sysfs control interface something like: /sys/bus/net-serial/drivers/rfc2217/ with nodes: endpoint_add # echo "${IPv4} ${BASE_PORT} 16" > endpoint_add # creates /dev/ttyNET0p0 - p15 endpoint_add # echo "${IPv6} ${BASE_PORT} 8" > endpoint_add # creates /dev/ttyNET1p0 - p8 endpoints # cat endpoints; "0 ${IPv4} ${BASE_PORT} 16", "1 ${IPv6} ${BASE_PORT} 8" endpoint_del # echo 0 > endpoint_del Because RFC2217 is only one flavour of network-attached serial ports my thoughts are to create two modules, the first being a generic "ttynet" module that manages tty creation, configuration, tear-down and network connection when a port is opened, and a specialised rfc2217 module that depends on "ttynet" and knows how to talk to RFC2217 devices. That would provide ready support for other types of networked serial device such as raw (which the generic module should probably do by default). Because some access devices support more than one serial protocol (RS232, RS422, RS485, etc.) I'm wondering how that should be represented in the driver - possibly another parameter passed to "endpoint_add", or an additional per-port setting (since access devices allow per-port setting) ? Thanks in advance. [*] Moxa do provide an out-of-tree driver for the NPort series but it only works in the NPort-specific 'Real COM' mode, not RFC2217 [1] http://tools.ietf.org/html/rfc2217 [2] http://www.moxa.com/product/NPort_6650.htm

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Re: Kernelnewbies Digest, Vol 45, Issue 1
by Vishwas Srivastava Aug. 1, 2014

Aug. 1, 2014

To run menuconfig programme you need "ncurses" package, which is not installed on your system That is the reason of your first problem. Now, your ubuntu version, looks like obsolete (i believe you installed it long time before)and is no longer supported anymore. If you update your ubuntu version, i guess you would be able to install ncurses and would be able to build (make menuconfig wont fail). Hope it would help. On Fri, Aug 1, 2014 at 9:30 PM, <kernelnewbies-request(a)kernelnewbies.org> wrote: > Send Kernelnewbies mailing list submissions to > kernelnewbies(a)kernelnewbies.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > or, via email, send a message with subject or body 'help' to > kernelnewbies-request(a)kernelnewbies.org > > You can reach the person managing the list at > kernelnewbies-owner(a)kernelnewbies.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Kernelnewbies digest..." > > > Today's Topics: > > 1. apt-get is not working properly (Niamathullah sharief) > 2. Process simulator (Niamathullah sharief) > 3. Re: Process simulator (Raghavendra) > 4. Re: apt-get is not working properly (Niamathullah sharief) > 5. Re: apt-get is not working properly (Kristofer Hallin) > 6. Kernel Networking Ideas??? (Aniket Shinde) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 1 Aug 2014 11:14:05 +0530 > From: Niamathullah sharief <newbiesha(a)gmail.com> > Subject: apt-get is not working properly > To: kernelnewbies <Kernelnewbies(a)kernelnewbies.org>, > kernelnewbies(a)nl.linux.org > Message-ID: > <CACZhsRgir3UAVmshhnK1hH1cJKG9ZfT8_rmh=+ > WEgY_oTmfNBQ(a)mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > Dear Friends > > I am trying to install my ncurses package in my Ubuntu Distro. > > I am getting the following error. But i dont know what is the problem. Can > anyone help me > > Code: > > mamse@mamse-ThinkCentre-M80:~/linux-3.15.8$ sudo apt-get install > ncurses-develReading package lists... Done > Building dependency tree > Reading state information... Done > E: Unable to locate package ncurses-devel > mamse@mamse-ThinkCentre-M80:~/linux-3.15.8$ >

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Kernel Networking Ideas???
by Aniket Shinde Aug. 1, 2014

Aug. 1, 2014

Hey, Any project available in Networking under Kernel??? *ANI*

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userspace stack start and end
by Xin Tong Aug. 1, 2014

Aug. 1, 2014

I am trying to find the start and end address of the userspace stack. I see in the task_struct there is start_stack. But I could not find end_start anywhere in the kernel code ? Can someone please tell me how to find the end of the stack ? Thanks, Xin

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Re: apt-get is not working properly
by Niamathullah sharief Aug. 1, 2014

Aug. 1, 2014

Actually it is not only my distro problem. I am trying to compile kernel in Ubuntu. I am getting the following error and i am unable to rectify it. *mamse@mamse-ThinkCentre-M80:~/linux-3.15.8$ make menuconfig *** Unable to find the ncurses libraries or the *** required header files. *** 'make menuconfig' requires the ncurses libraries. *** *** Install ncurses (ncurses-devel) and try again. *** make[1]: *** [scripts/kconfig/dochecklxdialog] Error 1make: *** [menuconfig] Error 2mamse@mamse-ThinkCentre-M80:~/linux-3.15.8$* On Fri, Aug 1, 2014 at 11:19 AM, David kiarie <davidkiarie4(a)gmail.com> wrote: > In future, ask this distro related questions on the ubuntu forums, or > even try google :-) > > Looking at your problem it seems that ncurses-devel is not the package > name for what you are looking for. > > You could try, "apt-cache search ncurses", from the list, get the > name of the package you are looking for. > > On Fri, Aug 1, 2014 at 8:44 AM, Niamathullah sharief > <newbiesha(a)gmail.com> wrote: > > Dear Friends > > > > I am trying to install my ncurses package in my Ubuntu Distro. > > > > I am getting the following error. But i dont know what is the problem. > Can > > anyone help me > > > > Code: > > > > mamse@mamse-ThinkCentre-M80:~/linux-3.15.8$ sudo apt-get install > > ncurses-develReading package lists... Done > > Building dependency tree > > Reading state information... Done > > E: Unable to locate package ncurses-devel > > mamse@mamse-ThinkCentre-M80:~/linux-3.15.8$ > > > > > > _______________________________________________ > > Kernelnewbies mailing list > > Kernelnewbies(a)kernelnewbies.org > > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > >

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Process simulator
by Niamathullah sharief Aug. 1, 2014

Aug. 1, 2014

Dear Friends, Can anyone tell me how to find the process execution time in linux? I mean how much time it is taking to execute any process in our conventional processor. Please help me

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apt-get is not working properly
by Niamathullah sharief Aug. 1, 2014

Aug. 1, 2014

Dear Friends I am trying to install my ncurses package in my Ubuntu Distro. I am getting the following error. But i dont know what is the problem. Can anyone help me Code: mamse@mamse-ThinkCentre-M80:~/linux-3.15.8$ sudo apt-get install ncurses-develReading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package ncurses-devel mamse@mamse-ThinkCentre-M80:~/linux-3.15.8$

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Work
by Nick Krause Aug. 1, 2014

Aug. 1, 2014

Is there any work for a kernel newbie that you guys known of? Cheers Nick

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Makedumpfile from Raw file
by Lucas Tanure Aug. 1, 2014

Aug. 1, 2014

Hi, Can I create a vmcore (elf format) using makedumpfile from a Raw file ? So I can debug using vmlinux and gdb ? thanks -- Lucas Tanure +55 (19) 988176559

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