December 2012 - kernelnewbies@kernelnewbies.org

how to look for source code in kernel
by kishore kumar Dec. 28, 2012

Dec. 28, 2012

can anybody tell me how to look into source code, as most are hidden in kernel.

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Bad magic number and
by sham pavman Dec. 28, 2012

Dec. 28, 2012

Hi all, I'm having a problem with a SCSI driver... When I load the module (from dmesg) I see that everything has worked fine. and the output of fdisk -l shows the <SNIP> sudo fdisk -l Disk /dev/sda: 60.0 GB, 60022480896 bytes 255 heads, 63 sectors/track, 7297 cylinders, total 117231408 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000539c8 Device Boot Start End Blocks Id System /dev/sda1 * 2048 78125055 39061504 83 Linux /dev/sda2 78127102 82124799 1998849 5 Extended /dev/sda5 78127104 82124799 1998848 82 Linux swap / Solaris Disk /dev/sdb: 300.1 GB, 300101401088 bytes <-- this is the guy 255 heads, 63 sectors/track, 36485 cylinders, total 586135549 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xffffffff Disk /dev/sdb doesn't contain a valid partition table <SNIP> So i used fdisk on "sdb" to manually write the tables in and it succeeded <SNIP> Command (m for help): n Partition type: p primary (0 primary, 0 extended, 4 free) e extended Select (default p): p Partition number (1-4, default 1): 1 First sector (2048-586135548, default 2048): Using default value 2048 Last sector, +sectors or +size{K,M,G} (2048-586135548, default 586135548): Using default value 586135548 Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks. <SNIP> THen i used mkfs to create a new ext4 partition and even that went fine. <SNIP> mkfs -t ext4 /dev/sdb mke2fs 1.42 (29-Nov-2011) /dev/sdb is entire device, not just one partition! Proceed anyway? (y,n) y Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 18317312 inodes, 73266943 blocks 3663347 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=4294967296 2236 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616 Allocating group tables: done Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done root@ocz-Not-Specified:/home/ocz/Shampavman/OCZ_XEN_Final_Source_code# echo $? 0 <SNIP> But then when i tried to mount it on /mnt things fail. <SNIP> mount -t ext4 /dev/sdb /mnt/test mount: wrong fs type, bad option, bad superblock on /dev/sdb, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so ------------------------------------ dmesg..... [495515.858203] EXT4-fs (sdb): VFS: Can't find ext4 filesystem ---------------------------- <SNIP> ===================== Some pointers, While diving into this issue i figured out that the magic number on this device is not the same as "EXT4_SUPER_MAGIC" macro that is checked for in the super.c (fs/ext4/super.c) . Can anyone please help me in figuring out a solution for this.? Thanks

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Re: What does ISA/PCI really mean to ARM architecture?
by anish kumar Dec. 27, 2012

Dec. 27, 2012

On Thu, 2012-12-27 at 11:22 -0500, jonsmirl(a)gmail.com wrote: > On Thu, Dec 27, 2012 at 3:27 AM, Woody Wu <narkewoody(a)gmail.com> wrote: > > Hi, list > > > > I know this might be a very basic question. But I really don't clear at > > it. > > > > Can a peripheral chip that claims to be ISA or PCI device be used in a > > ARM based embedded system? For these kind of chips, I only concern > > about the planar kind of devices, means they are not on a dedicated > > expansion card. > > > > From hardware point of view, to attach a ISA or PCI planar chip, is > > there any requirement need to fulfill on a ARM board? > > See if your ARM CPU has an interface for SRAM (in addition to DRAM). > You can use a SRAM chip select to access ISA type devices. But you may Would you mind explaining this in detail? > need additional buffers/latches to do this. > > Another solution is to attach you peripherals using USB. Almost all Connect using USB what does this mean? > embedded wifi chips are attached this way. The USB connectors aren't > required, you can route USB around on your PCB. USB hub chips are > $0.35 if you need more ports. USB Ethernet chips are available. > > Other options include SPI/I2C. It is worthwhile to investigate these Only chips which support SPI/I2C can be used but ISA/PCI is completely orthogonal to this AFAIK. > serial solutions before doing a parallel solution. Parallel buses eat > up a lot of PCB space. > > > > > > From Linux driver point of view, what are needed to support an ISA or > > PCI driver in ARM architecture? More important, is ISA or PCI device a > > platform device? If not, how to add these kind of devices in my board > > definition? > > > > I know my question might not be reasonable enough, if I messed concepts, > > please sort me out. > > > > > > Thanks in advance. > > > > > > -- > > woody > > I can't go back to yesterday - because I was a different person then. > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo(a)vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > > > > -- > Jon Smirl > jonsmirl(a)gmail.com > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo(a)vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/

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Re: What does ISA/PCI really mean to ARM architecture?
by anish kumar Dec. 27, 2012

Dec. 27, 2012

On Thu, 2012-12-27 at 10:51 +0100, Geert Uytterhoeven wrote: > On Thu, Dec 27, 2012 at 9:27 AM, Woody Wu <narkewoody(a)gmail.com> wrote: > > Can a peripheral chip that claims to be ISA or PCI device be used in a > > ARM based embedded system? For these kind of chips, I only concern > > about the planar kind of devices, means they are not on a dedicated > > expansion card. > > > > From hardware point of view, to attach a ISA or PCI planar chip, is > > there any requirement need to fulfill on a ARM bard? arm AFAIK is only used in embedded system but ISA/PCI buses are generally part of 'big systems' and most of the times it refers to x86 PC. > > > > From Linux driver point of view, what are needed to support an ISA or > > PCI driver in ARM architecture? More important, is ISA or PCI device a > > platform device? If not, how to add these kind of devices in my board > > definition? AFAIK, Platform device is just a way to add a particular driver whose probe can't be called at runtime.Mostly platform device is part of system on chip. PCI devices probe function will be called by the PCI bus as and when it detects any activity on the bus.So you don't need PCI device to be a platform device. > > An ISA device is typically a platform device. For ARM, which uses device trees, Don't know much about ISA device to comment on this but people familiar with this can enlighten us as to the reason why it is platform device in detail. > this means you define it in the device tree. > > A PCI device is not a platform device, as devices on a PCI bus can be > probed automatically. The PCI host bridge is typically a platform device, > though, so it it should be in your device tree. > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert(a)linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo(a)vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/

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Regarding ioctl()
by Rahul Bedarkar Dec. 27, 2012

Dec. 27, 2012

Hi, When ioctl() is called from user space, how device driver related to it comes into picture ? What is flow from user space to kernel space ? Thanks, Rahul Bedarkar

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What does ISA/PCI really mean to ARM architecture?
by Woody Wu Dec. 27, 2012

Dec. 27, 2012

Hi, list I know this might be a very basic question. But I really don't clear at it. Can a peripheral chip that claims to be ISA or PCI device be used in a ARM based embedded system? For these kind of chips, I only concern about the planar kind of devices, means they are not on a dedicated expansion card. >From hardware point of view, to attach a ISA or PCI planar chip, is there any requirement need to fulfill on a ARM bard? >From Linux driver point of view, what are needed to support an ISA or PCI driver in ARM architecture? More important, is ISA or PCI device a platform device? If not, how to add these kind of devices in my board definition? I know my question might not be reasonable enough, if I messed concepts, please sort me out. Thanks in advance. -- woody I can't go back to yesterday - because I was a different person then.

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Need to Add Documents in Linux kernel
by Javed Iqbal Dec. 27, 2012

Dec. 27, 2012

Hi, I just want to know that can I add documents in linux kernel version 3.x.x.?? If yes then please tell me the procedure to add the documents? Thanks & Regards Javed Iqbal

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Fedora kernel rpmbuild query
by Shraddha Kamat Dec. 26, 2012

Dec. 26, 2012

Hi List, I do the following on Fedora kernel src rpm : (1) rpm -ivh kernel-xxx.rpm (2) Go to ~/rpmbuild/SPECS dir (2) rpmbuild -bp kernel.specs --nodeps then in the ~/rpmbuild/BUILD/ dir I get kernel-xxx dir where in there are two source dir - (1) linux-xxx <-------- A (2) vanilla-xxx <-------- B Why are these two dir created - How do I use the configuration file /boot/config-xxx to build vmlinuz and initrd image ? Which dir A or B sould I use for building ? -- Shraddha

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3.7.1 (and linux-next): doesn't compile without CONFIG_ACPI
by Alexei Colin Dec. 25, 2012

Dec. 25, 2012

Hi, Is the following worth forwarding to the main list? It might be an artifact of my cross-compilation toolchain. Compilation without CONFIG_ACPI fails [1] because the headers include/acpi/* throw errors if included without CONFIG_ACPI. They are included unconditionally from two places: (1) acpi/acpi.h from iscsi_ibft.h from arch/x86/kernel/setup.c. The include of iscsi_ibft.h was harmless until an include of acpi/acpi.h was added to it in 4e639fdf0d0d745648aa62228ab8a0d9c03a563f (2) acpi/acpi_bus.h from pci-label.c, which used to only be compiled when ACPI was on, but that changed in 8a226e00eeed8db843d4a580013a49ae3559bcd7 to compile it even when only DMI and not ACPI is on. Putting CONFIG_ACPI guards around both includes lets the compilation proceed. [1] The errors are of this nature: include/acpi/actypes.h:55:2: error: #error ACPI_MACHINE_WIDTH not defined

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Porting problem: ndo_set_multicast_list removed
by Woody Wu Dec. 24, 2012

Dec. 24, 2012

Hi, list I am porting an ethernet driver from 2.6.x to 3.7.1. I found in the new kernel, the ndo_set_multicast_list method in the net_device_ops had been removed. What's the story behind? Can I simply ignore this method defined in an old driver? Please also help to check the below code, is the list of the operations defined for my driver enough or not? const struct net_device_ops ax_netdev_ops = { .ndo_open = mydriver_open, .ndo_stop = mydriver_close, .ndo_start_xmit = mydriver_start_xmit, .ndo_get_stats = mydriver_get_stats, /*.ndo_set_multicast_list = mydriver_set_multicast_list,*/ .ndo_set_mac_address = mydriver_set_mac_address, }; Thanks in advance. -- woody I can't go back to yesterday - because I was a different person then.

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