Hi, I see lot of modalias files under /sys directory. For e.g: # cat /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/modalias pci:v00001556d00005555sv00004000sd00000000bc08sc05i01 I would like to know which part of the kernel module creates sysfs modalias file? How does udev load modules dynamically when a new device is added? Where should I look for default udev rules? -- Thanks, Sekhar
On Fri, Jun 03, 2016 at 10:02:02PM +0530, Muni Sekhar wrote:
Hi,
I see lot of modalias files under /sys directory.
For e.g:
# cat /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/modalias
pci:v00001556d00005555sv00004000sd00000000bc08sc05i01
I would like to know which part of the kernel module creates sysfs modalias file?
The kernel bus code for the device that the bus is on creates this. For this example, the PCI bus code does this work.
How does udev load modules dynamically when a new device is added?
The book, "Linux Device Drivers, version 3", free online, has a whole section on this, I suggest reading it.
Where should I look for default udev rules?
In the udev or systemd package on your machine. Specific ways to do this depends on your distro. greg k-h
Muni Sekhar <munisekharrms@gmail.com> writes:
I see lot of modalias files under /sys directory.
For e.g:
# cat /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/modalias
pci:v00001556d00005555sv00004000sd00000000bc08sc05i01
I would like to know which part of the kernel module creates sysfs modalias file?
lots of different places. Do a "git grep modalias drivers/" to see many of them. That particular file is created by drivers/pci/pci-sysfs.c Bjørn
On Sat, Jun 4, 2016 at 12:20 AM, Bjørn Mork <bjorn@mork.no> wrote:
Muni Sekhar <munisekharrms@gmail.com> writes:
I see lot of modalias files under /sys directory.
For e.g:
# cat /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/modalias
pci:v00001556d00005555sv00004000sd00000000bc08sc05i01
I would like to know which part of the kernel module creates sysfs modalias file?
lots of different places. Do a "git grep modalias drivers/" to see many of them. That particular file is created by drivers/pci/pci-sysfs.c
Bjørn
Thanks Greg & Bjørn. -- Thanks, Sekhar
participants (3)
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Bjørn Mork -
Greg KH -
Muni Sekhar