Problem with rootfs mounting
Hello all, I am porting linux-2.6.37 to a new architecture, and I am facing the well-known problem: VFS: Cannot open root device "(null)" or unknown-block(0,0) When I was working on uClinux, I have seen that the vmlinux image was concatenated with the romfs image. The kernel was aware of the address of the magic number -rom1fs- thanks to the configuration CONFIG_MTD_UCLINUX_ADDRESS= 0x . . . . in the .config file. But, I have not found how I can do this in Linux.. I have chosen the filesystem ROMFS in the .config file. Where and how the romfs tree is created and included to the kernel image? This question concerns also all the necessary user applications like "init" and "sh". Should I use a build system tool like Buildroot or OpenEmbedded? Any help will be very useful. Thanks in advance. ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Problem with rootfs mounting
Hello all, I am porting linux-2.6.37 to a new architecture, and I am facing the well-known problem: VFS: Cannot open root device "(null)" or unknown-block(0,0) When I was working on uClinux, the vmlinux image was concatenated with the romfs image. The kernel was aware of the address of the magic number -rom1fs- thanks the configuration CONFIG_MTD_UCLINUX_ADDRESS= . . . in the .config file. But, I have not found how I can do thit in Linux.. Where and how the romfs tree is created and included to the kernel image? This question concerns also all the necessary user applications like "init" and "sh". Any help will be very useful. Thanks in advance. ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Common signal handler system call
On Mon, Mar 21, 2011 at 4:08 PM, Bernd Petrovitsch < be...@petrovitsch.priv.at> wrote: > On Son, 2011-03-20 at 13:08 +0530, mohit verma wrote: [...] > > I think it should be there in kernel not because it is my idea but for > > good reasons (personally think so). > > ... and despite IMHO good reason for not including. > But talk is cheap so prepare and propose a working prototype as patch > and we will see the reaction from others. > > thanks a lot Bernd. I am gonna do it. I'm not strong against it but I do not see any significant advantage but > at least one open question and the burden to all which do not need/use > it[0]. > > ad "POSIX compliance": Well, there are lots of system calls (in the > Linux kernel) which are not in POSIX (or SuSv3 or ...) - plain simply > because they are newer than these "standards" or out of the scope of > them. > And (on Linux with and/or without GNU-libc) some system-calls (or > whatever POSIX calls them) are "only" libc functions which are > transformed into other, real existing system-calls. > > Bernd > > [0]: And that is partly due to my embedded background where you strive > to make everything small and avoid bloat;-) > -- > Bernd Petrovitsch Email : be...@petrovitsch.priv.at > LUGA : http://www.luga.at > > -- *MOHIT VERMA* ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Common signal handler system call
On Son, 2011-03-20 at 13:08 +0530, mohit verma wrote: [...] > I think it should be there in kernel not because it is my idea but for > good reasons (personally think so). ... and despite IMHO good reason for not including. But talk is cheap so prepare and propose a working prototype as patch and we will see the reaction from others. I'm not strong against it but I do not see any significant advantage but at least one open question and the burden to all which do not need/use it[0]. ad "POSIX compliance": Well, there are lots of system calls (in the Linux kernel) which are not in POSIX (or SuSv3 or ...) - plain simply because they are newer than these "standards" or out of the scope of them. And (on Linux with and/or without GNU-libc) some system-calls (or whatever POSIX calls them) are "only" libc functions which are transformed into other, real existing system-calls. Bernd [0]: And that is partly due to my embedded background where you strive to make everything small and avoid bloat;-) -- Bernd Petrovitsch Email : be...@petrovitsch.priv.at LUGA : http://www.luga.at ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: PCI Configuration Space
Hi... On Mon, Mar 21, 2011 at 10:46, Joy wrote: > The question is simple. > > If I am able to read PCI device's configuration space, where is it? > > Is it in Main Memory (in general, DDR3) mapped? Or Is it in the device's > own memory? Does "lspci -vv" help? -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: how can I get page fault addressed with perf
Hi... On Sun, Mar 20, 2011 at 16:15, zhao bao wrote: > Hi, I want to trace page faults in my program. The result I wanted like > this: > 1st page fault at addrA. > 2nd page fault at addrB. > 3rd page fault at addrC Not sure about perf, but once I got the same idea when I wanna simulate in the simplest way on how stuffs like Xen manage shadow page table. The idea is by piggy backing SIGSEGV handler. I was heavily inspired by Phrack : http://www.phrack.org/issues.php?issue=58&id=3 Check the =[ 0x01 ]= part "Subject: Getting rid of SIGSEGV - for fun but not for profit" Good luck... -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Problem compiling BCM Wireless driver on 2.6.37 (lib80211 symbol issue)
Hi Greg, On Mon, Mar 21, 2011 at 12:20 AM, Greg KH wrote: > On Sun, Mar 20, 2011 at 11:42:36PM +0530, Shreyansh Jain wrote: >> Hi Greg >> >> > >> > Why not ask the authors of that code? As it is closed source, they are >> > the only ones that can legally help you out. >> >> Well, I have not considered asking the authors because I have the >> code, I can successfully compile it and then, unable to link to the >> kernel because of a missing function which is present in another >> module and exported in the kernel. > > Wait, why ask some random people instead of the people who can actually > fix the problem for you (i.e. the authors of the code?) > >> Yes, this driver might not be GPL'd, but I certainly have its code. > > Yes, but note that just because you have the code, that doesn't mean > that anyone else has the rights to change it (including you), or help > you out. Please read the license for what you have before making > assumptions. Right, I understand your point and apologize for being callous enough pertaining to the licensing issues. Actually, I just went ahead and read the license terms and (as far as what I can make sense of the legal language) it doesn't restrict changes in the code until and unless I am not distributing it and not breaking any IEEE standard compatibility (once again, in case distributing it with a broadcom device). Nevertheless, I will try and search for correct people to answer this or reframe the question in more generic terms if problem still persists. Thanks for correcting me! > > best of luck, > > greg k-h > - Shreyansh ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: User space context switch
thanks vimal and mulyadi. On Mon, Mar 21, 2011 at 12:32 PM, Vimal wrote: > Hi Mohit, > > On 18 March 2011 13:07, mohit verma wrote: > > hi all, > > is it possible to write a user space code to calculate the context > switch > > time of a process ? I mean , how can the user space code know about the > > working of the scheduler? > > Is there any system call API to interact with scheduler or something > other > > to interact with , regarding this problem? > > Do check the function tracing framework in the Linux Kernel. > > Links: > * http://lwn.net/Articles/322666/ > * http://lwn.net/Articles/290277/ > > sched_switch is the tracer you're looking for. > > -- > Vimal > -- *MOHIT VERMA* ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: User space context switch
Hi Mohit, On 18 March 2011 13:07, mohit verma wrote: > hi all, > is it possible to write a user space code to calculate the context switch > time of a process ? I mean , how can the user space code know about the > working of the scheduler? > Is there any system call API to interact with scheduler or something other > to interact with , regarding this problem? Do check the function tracing framework in the Linux Kernel. Links: * http://lwn.net/Articles/322666/ * http://lwn.net/Articles/290277/ sched_switch is the tracer you're looking for. -- Vimal ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
