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FPGA registers userspace interface?
by Kfir Lavi Jan. 3, 2011

Jan. 3, 2011

Hi, I have a FPGA that is constantly changing (its on development phase). I want to let userspace app to update those registers, but don't want to create an API yet. What is the best way to open a range of registers to userspace, so no driver update is required? Thanks, Kfir

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small ata driver enhancement project for someone
by Greg Freemyer Jan. 3, 2011

Jan. 3, 2011

All, I don't think the kernel is yet tracking SSD vs Rotational. It would be a nice patch if someone would do that. I don't maintain the subsystem, but I assume it would be accepted if well done. You could model your patch by looking at how the drive topology patches were done. Effectively this patch would do the same thing. (Petersen wrote those, so I think these are them: http://markmail.org/message/azj3z4tofrknnbbe) My thoughts: ===> How to tell For SATA: Per T13/1699-D Revision 4a (from May 2007) word 217 of the identify block should be populated with a "1" to identify non-rotating media. http://www.t13.org/Documents/UploadedDocuments/docs2007/D1699r4a-ATA8-ACS.p… IIRC: The identify block is read during drive query time, so you should not have to actually generate any i/o. Just patch the portion of the kernel working with the identify block. ie. See the topology patch. For SCSI - no idea, but I'd be surprised if they did not already have a scsi flag for it. The topology patch also handled SCSI, so it's just a matter of finding the scsi field to use. ===> Quirks Lots of manufacturers don't follow the specs on something like this, so a quirks functionality is typically how the ATA driver handles it. ie. If you find a SSD that is not setting the flag, then setup a quirk to override the flag. The quirk table should be based on make & model at a minimum, and maybe firmware. You should be able to find existing quirk logic, so don't invent your own. SCSI seems to be followed much more accurately, so you may not need a quirks functionality for it. ===> userspace API Seems like there should be a "/sys/block/sda/*" file that allows userspace to interrogate. The topology patches added a few of these, so one more would be good. If you can generate the same data for scsi, maybe just create /sys/block/sda/rotation_speed and have it just reflect exactly word 217 of the identify block. Greg

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Kernel newbies archives of yesteryears
by Prabhu nath Jan. 3, 2011

Jan. 3, 2011

Dear All, Where do we find the archives of kernelnewbies of yesteryears ? Currently, I find only Dec 2010 and Jan 2011. The archives I refered is http://lists.kernelnewbies.org/pipermail/kernelnewbies/ Thanks, Prabhu

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some questions about errno.h
by vichy Jan. 2, 2011

Jan. 2, 2011

Dear all: I found there are 2 errno.h we can include when coding. #include <asm-generic/errno.h> and #include <linux/errno.h> is there difference or rue I need to follow when I want to take advantage of errno in kernel? thanks for your help, vichy

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Adding a kobject in the device model hierarchy
by Prabhu nath Jan. 2, 2011

Jan. 2, 2011

Dear All, I have written one pseudo char driver. I have initialized the device generic structure with cdev_init function. This will initialize the kobject structure embedded within struct cdev with appropriate ktype. If I want to add this kobject in /sys/devices/virtual/misc/ location of sysfs, how is the following fields set * kobj->parent * kobj->kset * kobj->kset->obj. Also, in general how to look out for the parent kobject ? Would like to know, if there are mechanisms provisioned by Linux Kernel. Robert: My 2 cents as I am reading the LKD(3rd edition), it would be appropriate to add one example as a solution to the above problem. Generally, it has been told as kobj->kset = my_kset in Page # 353. Note: Even in LDD(3rd editon page 369). It has been mentioned that "The kobject's kset field must be pointed at the kset of interest" Thanks, Prabhu

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How to know when any process is trying to establish an internet connection?
by Arreche Jan. 1, 2011

Jan. 1, 2011

Hi, I have multiple network interfaces(Ethernet, GPRS and Modem). Is possible to setup them on demand? And to block a process until It gets connection by any interface? Thanks. -- .

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How to use kgdb and kdb
by AQ Tast Jan. 1, 2011

Jan. 1, 2011

Hello Everyone, I am trying to get my hands dirty with kernel programming and came across kgdb and kdb. Can someone point me to a tutorial which a newbie can easily get through. Also I was looking forward for using Qemu / VBox for my experiments. Would be nice if there are tutorials on how to debug using these tools. Regards, Tast

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How to buid and install kernel 2.6.36.2 on OpenSuse 11.2
by lan li Dec. 31, 2010

Dec. 31, 2010

Hi, everyone I see how to build and install linux kernel on Ubuntu from the emails. But I would like to install latest kernel to OpenSue. There might some differences from installing it on Ubuntu. Lina

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Intel i915 and Xorg
by Alex John Dec. 31, 2010

Dec. 31, 2010

There seems to be no specific options in the configuration for i915's. If I'm not wrong, it uses the same as for the i8x's and so on? Xorg at the moment complains that it can't find the module i915 on my gentoo box but then I haven't modulised anything much. Can someone confirm the configuration that is needed for modsetting (with) and i915? -- Cheers Alex

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how CS will points to __KERNEL_CS when interrupt is received in User-Mode
by Darshan Ghumare Dec. 31, 2010

Dec. 31, 2010

Hi all, On x86 how CS will points to __KERNEL_CS when interrupt is received in User-Mode. Regards Darshan

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