May 2011 - kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

simple question about accessing pci io registers
by Prashant Shah May 18, 2011

May 18, 2011

Hi, I am trying to interface a PCI Data Acquisition card with Linux. Vendor has been kind enough to provided us the internal register specification which is very simple. It uses two IO Address Spaces The first address space is for reading and writing analog input (base address register 2) READ : base + offset 0 : analog in conversion data base + offset 1 : analog in conversion data base + offset 2 : not used base + offset 3 : not used WRITE : base + offset 0 : analog out conversion data base + offset 1 : analog out conversion data base + offset 2 : bit level : X X (2 bit select uni polar or bi polar) (4 bit channel selection) base + offset 3 : trigger all transfers are 16 bit. Sequence of operation is : 1. write to (WRITE + offset 2) = 0000 2. read from (READ + offset 0) I am not able to get the reading from the device. It always shows 0x8000 I tried the same thing under windows using a PCI testing/sniffer tool it works properly. Please check the function dyna_pci1050_read_proc I dont know what I am doing wrong here. Is this the write way to access PCI IO Ports ? -------- CODE ---------- #include <linux/interrupt.h> #include <linux/sched.h> #include <linux/proc_fs.h> #include <linux/pci.h> #include <linux/delay.h> #define PCI_VENDOR_ID_DYNALOG 0x10b5 #define PCI_DEVICE_ID_DYNALOG_PCI_1050 0x1050 #define DRV_NAME "dyna_pci1050" unsigned long iobase0, iobase1, iobase2, iobase3, iobase4, iobase5; static int dyna_pci1050_read_proc(char *page, char **start, off_t offset, int count, int *eof, void *data) { u16 data16; printk(KERN_INFO "comedi: dyna_pci1050: %s\n", __func__); data16 = 0x0000; outw(iobase2 + 2, data16); mb(); udelay(100); data16 = inw(iobase2); printk(KERN_INFO "reading data from 0x%4lx : %x\n", iobase2, data16); return 0; } /************************* CONFIG FUNCTIONS ***********************************/ static int dyna_pci1050_probe(struct pci_dev *dev, const struct pci_device_id *id) { int counter = 0; unsigned long pci_resource; printk(KERN_INFO "comedi: dyna_pci1050: %s\n", __func__); pci_enable_device(dev); /* deivce related information */ printk(KERN_ERR "comedi: dyna_pci1050: bus number %d\n", dev->bus->number); printk(KERN_ERR "comedi: dyna_pci1050: device id %x\n", dev->device); printk(KERN_ERR "comedi: dyna_pci1050: vendor id %x\n", dev->vendor); printk(KERN_ERR "comedi: dyna_pci1050: slot number %d\n", PCI_SLOT(dev->devfn)); printk(KERN_ERR "comedi: dyna_pci1050: function number %d\n", PCI_FUNC(dev->devfn)); for (counter = 0; counter < 6; counter++) { pci_resource = pci_resource_start(dev, counter); printk(KERN_INFO "comedi: dyna_pci1050 : pci_resource_start : %d : %016lX\n", counter, pci_resource); pci_resource = pci_resource_end(dev, counter); printk(KERN_INFO "comedi: dyna_pci1050 : pci_resource_end : %d : %016lX\n", counter, pci_resource); pci_resource = pci_resource_flags(dev, counter); printk(KERN_INFO "comedi: dyna_pci1050 : pci_resource_flags : %d : %016lX\n", counter, pci_resource); } iobase0 = pci_resource_start(dev, 0); iobase1 = pci_resource_start(dev, 1); iobase2 = pci_resource_start(dev, 2); iobase3 = pci_resource_start(dev, 3); iobase4 = pci_resource_start(dev, 4); iobase5 = pci_resource_start(dev, 5); printk(KERN_INFO "comedi: dyna_pci1050: iobase 0x%4lx : 0x%4lx : 0x%4lx : 0x%4lx : 0x%4lx : 0x%4lx\n", iobase0, iobase1, iobase2, iobase3, iobase4, iobase5); if (request_region(iobase1, 4, DRV_NAME)) printk(KERN_INFO "comedi: dyna_pci1050: acquired iobase1 0x%4lx\n", iobase1); else printk(KERN_INFO "comedi: dyna_pci1050: failed acquiring iobase1 0x%4lx\n", iobase1); if (request_region(iobase2, 4, DRV_NAME)) printk(KERN_INFO "comedi: dyna_pci1050: acquired iobase2 0x%4lx\n", iobase2); else printk(KERN_INFO "comedi: dyna_pci1050: failed acquiring iobase2 0x%4lx\n", iobase2); if (request_region(iobase3, 4, DRV_NAME)) printk(KERN_INFO "comedi: dyna_pci1050: acquired iobase3 0x%4lx\n", iobase3); else printk(KERN_INFO "comedi: dyna_pci1050: failed acquiring iobase3 0x%4lx\n", iobase3); create_proc_read_entry("dynalog", 0, NULL, dyna_pci1050_read_proc, NULL); return 0; } static void dyna_pci1050_remove(struct pci_dev *dev) { printk(KERN_INFO "comedi: dyna_pci1050: %s\n", __func__); release_region(iobase1, 4); release_region(iobase2, 4); release_region(iobase3, 4); remove_proc_entry("dynalog", NULL); } static struct pci_device_id ids[] = { { PCI_DEVICE(PCI_VENDOR_ID_DYNALOG, PCI_DEVICE_ID_DYNALOG_PCI_1050) }, { 0, }, }; MODULE_DEVICE_TABLE(pci, dyna_pci1050_driver); struct pci_driver dyna_pci1050_driver = { .name = DRV_NAME, .probe = dyna_pci1050_probe, .remove = dyna_pci1050_remove, .id_table = ids, }; static int __init dyna_pci1050_init(void) { printk(KERN_INFO "comedi: dyna_pci1050: %s\n", __func__); pci_register_driver(&dyna_pci1050_driver); return 0; } static void __exit dyna_pci1050_exit(void) { printk(KERN_INFO "comedi: dyna_pci1050: %s\n", __func__); pci_unregister_driver(&dyna_pci1050_driver); } module_init(dyna_pci1050_init); module_exit(dyna_pci1050_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Prashant Shah");

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KGDB problem at first breakpoint
by Prabhu nath May 18, 2011

May 18, 2011

Dear All, There is a problem with the KGDB at the very first break point after executing the gdb command "target remote /dev/ttyS0" from the host. I have verbatim, followed the KGDB document http://kernel.org/pub/linux/kernel/people/jwessel/kdb/ Problem Logs: --------------------- Details of my hardware and system software: ------------------------------------------------------------------- *Host (Development machine): * Intel Pentium IV Machine with Fedora Core 12 Linux Version : 2.6.31.5-127.fc12.i686.PAE gdb version : GNU gdb (GDB) Fedora (7.0-3.fc12) *Target:* Intel Pentium IV Machine with Fedora Core 12 Customized Linux Version : 2.6.38 Host is connected to Target via a null modem cable *Snapshot of .config of linux version 2.6.38 on the target * * * # CONFIG_DEBUG_RODATA is not set CONFIG_HAVE_ARCH_KGDB=y CONFIG_FRAME_POINTER=y CONFIG_DEBUG_INFO=y CONFIG_KGDB=y CONFIG_KGDB_SERIAL_CONSOLE=y CONFIG_KGDB_LOW_LEVEL_TRAP=y *Grub config on the target machine* * * title Fedora (2.6.38) root (hd0,0) kernel /boot/vmlinuz-2.6.38 ro root=UUID=fb7800fb-cfe7-438d-bc7f-c153ba4353d1 LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us*console=ttyS0,115200n8 kgdboc=ttyS0 kgdbwai*t initrd /boot/initrd-2.6.38.img On power on of the target, linux kernel boots and the logs are seen on the minicom console of the host and it will wait for the gdb on the host to connect. Here is the last 4 lines of the logs seen on the minicom Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A 00:06: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A kgdb: Registered I/O driver kgdboc. kgdb: Waiting for connection from remote gdb.. *--- Now I close the minicom console (Ctrl-A X) and start the gdb on the host. Here is the steps I follow. * * * *On the host machine:* * * [root@localhost kgdb]# gdb vmlinux GNU gdb (GDB) Fedora (7.0-3.fc12) Copyright (C) 2009 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html > This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i686-redhat-linux-gnu". For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>... Reading symbols from /root/kgdb/vmlinux...done. (gdb) set remotebaud 115200 (gdb) set debug remote 1 (gdb) target remote /dev/ttyS0 Remote debugging using /dev/ttyS0 Sending packet: $qSupported#37...Ack Packet received: Packet qSupported (supported-packets) is NOT supported Sending packet: $Hg0#df...Ack Packet received: OK Sending packet: $?#3f...Ack Packet received: S05 Sending packet: $Hc-1#09...Ack Packet received: OK Sending packet: $qC#b4...Ack Packet received: QC01 Sending packet: $qAttached#8f...Ack Packet received: Packet qAttached (query-attached) is NOT supported Sending packet: $qOffsets#4b...Ack Packet received: Sending packet: $g#67...Ack Packet received: 36000000ffffffff0abaffff20d98bc06c3f86de783f86de803ac8dd803f86de885747c00202000060000000680000007b00c8dd7b0086deffff0000ffff0000 Sending packet: $mc0475788,1#a4...Ack Packet received: 0f Sending packet: $mc0475788,8#ab...Ack Packet received: 0faef889f6ff0d08 Sending packet: $mc0475788,7#aa...Ack Packet received: 0faef889f6ff0d 0xc0475788 in ?? () Sending packet: $qSymbol::#5b...Ack Packet received: Packet qSymbol (symbol-lookup) is NOT supported (gdb) s Cannot find bounds of current function (gdb) *Observation:* *1.* Ideally the kernel being debugged should break at legitimate address and the corresponding line number should be displayed instead of " 0xc0475788 in ?? ()". 2. On inspecting section header in vmlinux executable, I found the .text section address range is from 0xC1000000 to 0xC1326e58 and no section's contents associate with the address 0xC0475788. *3.* Hence on single stepping, gdb logs the error as* "Cannot find bounds of current function"* * * Humbly request you to help me in addressing this issue. Thanks and Regards, Prabhu

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mm_init() functions in kernel code
by Vikram Narayanan May 18, 2011

May 18, 2011

Hi, I saw two mm_init functions in the kernel source code. 1) init/main.c (http://lxr.linux.no/#linux+v2.6.38/init/main.c#L530) 2) kernel/fork.c (http://lxr.linux.no/#linux+v2.6.38/kernel/fork.c#L482) Are the above functions go inside a single binary? How this doesn't produce a redefinition error? Thanks, Vikram

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About Open Firmware
by Jorgyano Bruno May 18, 2011

May 18, 2011

Hi all! I'm starting to develop for powerpc architecture and I have some soubts about the open firmware, does someone knows explain what it is and works or where I can find some information about this subject out the source code? I need a start point.

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How logs will come to UART serial console?
by sandeep kumar May 17, 2011

May 17, 2011

Hi , Here is my question. when we put 'printk's in kernel code the logs will go to the log_buffer.(i observed that from implementation) But when UART is enabled(in the bootloader), the same printk logs are going to the serial console. As per my study printk doesnot implementing anything that writes to the UART console. Now here are my questions, how this is being achieved? Where this is implemented?(which file) Where wil be the parsing of the cmdline string sent from the bootloader is done? Thanking you, sandeep kumar.

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How to debug /sys/power/state?
by Joy Sun May 17, 2011

May 17, 2011

Hi, I'm a newbie, and trying to understand the power control over linux. It looks that the basic power control would be achieved by /sys/power/state, but I can't find the starting point to look at it. Could somebody help me to find where takes the input from /sys/power/state in linux kernel code, please? (I've posted this before, but it doesn't look it appear in the list, so I re-post again.) Cheers, - Joy

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how to detect a user who changed a particular file in Linux.
by V.Ravikumar May 17, 2011

May 17, 2011

Hi all, (Note : I'm writing this mail to this kernel group as I did not find any suitable mechanism in application level for my below need). If a file modified by some user then how can we detect that user who modified it. Linux audit was not suitable for my need. Can this be achieved through kernel driver/module. Any other suggestions/help would be welcome. Thanks in advance. Regards, Ravikumar.

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Difference b/w CKRM and other linux schedulers
by Sowmya Sridharan May 17, 2011

May 17, 2011

Hi, In an attempt to understand CKRM, I need to find where it stands as compared to O(1) and CFS? What is difference between O(1), CFS and CKRM? What features differentiate them? Appreciate your inputs with regards to this. Thanks, Sowmya =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you

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Usbvideo dropped in linux-next?
by anish singh May 17, 2011

May 17, 2011

I was looking for drivers/staging/usbvideo folder but couldn't find it there. Is it dropped from linux-next?If yes then will it be included in future? Reference: http://www.spinics.net/lists/linux-next/msg14307.html One more question.I made a patch against http://git.kernel.org/?p=linux/kernel/git/sfr/linux-next.git;a=summary for drivers/staging/sm7xx.Is this the right linux-next git?

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Init error NFS booting a Fedora 13 file system
by Erlon Cruz May 16, 2011

May 16, 2011

Hi all, Im having the following problem to configure a diskless client. Everything seens to be OK. The client finds the kernel, loads the parameters, mount the NFS remote dir, but still cant find init. The error I get is: run-init: /sbin/init: No such file or directory Kernel Panic - not syncing: Attempted to kill init! Pid: 1 , comm: run-init Not tainted I know the the file system can find /sbin/init because I compiled a small hello World program and compiled statically and it runs normally. The question is: How can a make the real init run dynamically linked or how can I compile it statically? Kind regards, Erlon

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