On Sep 22, 2011, at 8:39 AM, Stephen Powell wrote: > On Tue, 20 Sep 2011 14:29:06 -0400 (EDT), David Roguin wrote: >> >> I was wondering, how does the kernel knows what module (or driver) >> to load given any hardware? And, can i see that in any log file? > > The kernel knows what module to load because the module contains > alias names based on the hardware's PCI id, USB id, ISA PnP id, > or some other hardware-identifying information. For example, > consider the following console session: > > ----- > > steve@smp3:~$ /sbin/modinfo 3c59x > filename: > /lib/modules/3.0.0-1custom2-686-pae/kernel/drivers/net/3c59x.ko > license: GPL > description: 3Com 3c59x/3c9xx ethernet driver > author: Donald Becker <bec...@scyld.com> > alias: pci:v000010B7d00009210sv*sd*bc*sc*i* > alias: pci:v000010B7d00009056sv*sd*bc*sc*i* > alias: pci:v000010B7d00001202sv*sd*bc*sc*i* > alias: pci:v000010B7d00001201sv*sd*bc*sc*i* > alias: pci:v000010B7d00009201sv*sd*bc*sc*i* > alias: pci:v000010B7d00004500sv*sd*bc*sc*i* > alias: pci:v000010B7d00006564sv*sd*bc*sc*i* > alias: pci:v000010B7d00006562sv*sd*bc*sc*i* > alias: pci:v000010B7d00006560sv*sd*bc*sc*i* > alias: pci:v000010B7d00005257sv*sd*bc*sc*i* > alias: pci:v000010B7d00005157sv*sd*bc*sc*i* > alias: pci:v000010B7d00005057sv*sd*bc*sc*i* > alias: pci:v000010B7d00005B57sv*sd*bc*sc*i* > alias: pci:v000010B7d00006056sv*sd*bc*sc*i* > alias: pci:v000010B7d00006055sv*sd*bc*sc*i* > alias: pci:v000010B7d00005055sv*sd*bc*sc*i* > alias: pci:v000010B7d00007646sv*sd*bc*sc*i* > alias: pci:v000010B7d00009805sv*sd*bc*sc*i* > alias: pci:v000010B7d00009800sv*sd*bc*sc*i* > alias: pci:v000010B7d00009202sv*sd*bc*sc*i* > alias: pci:v000010B7d00009200sv*sd*bc*sc*i* > alias: pci:v000010B7d0000905Asv*sd*bc*sc*i* > alias: pci:v000010B7d00009058sv*sd*bc*sc*i* > alias: pci:v000010B7d00009055sv*sd*bc*sc*i* > alias: pci:v000010B7d00009054sv*sd*bc*sc*i* > alias: pci:v000010B7d00009051sv*sd*bc*sc*i* > alias: pci:v000010B7d00009050sv*sd*bc*sc*i* > alias: pci:v000010B7d0000900Asv*sd*bc*sc*i* > alias: pci:v000010B7d00009006sv*sd*bc*sc*i* > alias: pci:v000010B7d00009005sv*sd*bc*sc*i* > alias: pci:v000010B7d00009004sv*sd*bc*sc*i* > alias: pci:v000010B7d00009001sv*sd*bc*sc*i* > alias: pci:v000010B7d00009000sv*sd*bc*sc*i* > alias: pci:v000010B7d00005952sv*sd*bc*sc*i* > alias: pci:v000010B7d00005951sv*sd*bc*sc*i* > alias: pci:v000010B7d00005950sv*sd*bc*sc*i* > alias: pci:v000010B7d00005970sv*sd*bc*sc*i* > alias: pci:v000010B7d00005920sv*sd*bc*sc*i* > alias: pci:v000010B7d00005900sv*sd*bc*sc*i* > depends: mii > intree: Y > vermagic: 3.0.0-1custom2-686-pae SMP mod_unload modversions 686 > parm: debug:3c59x debug level (0-6) (int) > parm: options:3c59x: Bits 0-3: media type, bit 4: bus mastering, > bit 9: full duplex (array of int) > parm: global_options:3c59x: same as options, but applies to all > NICs if options is unset (int) > parm: full_duplex:3c59x full duplex setting(s) (1) (array of int) > parm: global_full_duplex:3c59x: same as full_duplex, but applies to > all NICs if full_duplex is unset (int) > parm: hw_checksums:3c59x Hardware checksum checking by adapter(s) > (0-1) (array of int) > parm: flow_ctrl:3c59x 802.3x flow control usage (PAUSE only) (0-1) > (array of int) > parm: enable_wol:3c59x: Turn on Wake-on-LAN for adapter(s) (0-1) > (array of int) > parm: global_enable_wol:3c59x: same as enable_wol, but applies to > all NICs if enable_wol is unset (int) > parm: rx_copybreak:3c59x copy breakpoint for copy-only-tiny-frames > (int) > parm: max_interrupt_work:3c59x maximum events handled per interrupt > (int) > parm: compaq_ioaddr:3c59x PCI I/O base address (Compaq BIOS problem > workaround) (int) > parm: compaq_irq:3c59x PCI IRQ number (Compaq BIOS problem > workaround) (int) > parm: compaq_device_id:3c59x PCI device ID (Compaq BIOS problem > workaround) (int) > parm: watchdog:3c59x transmit timeout in milliseconds (int) > parm: global_use_mmio:3c59x: same as use_mmio, but applies to all > NICs if options is unset (int) > parm: use_mmio:3c59x: use memory-mapped PCI I/O resource (0-1) > (array of int) > steve@smp3:~$ > > ----- > > Do you see all those "alias" entries in the output of the modinfo command? > Each alias > entry corresponds to one or more Network Interface Cards (NICs). In some > cases, they are > stand-alone boards installed in an expansion slot. In other cases they are > built-in to > the motherboard. Now consider the following: > > ----- > > steve@smp3:~$ lspci -nn > 00:00.0 Host bridge [0600]: Intel Corporation 82850 850 (Tehama) Chipset Host > Bridge (MCH) [8086:2530] (rev 02) > 00:01.0 PCI bridge [0604]: Intel Corporation 82850 850 (Tehama) Chipset AGP > Bridge [8086:2532] (rev 02) > 00:1e.0 PCI bridge [0604]: Intel Corporation 82801 PCI Bridge [8086:244e] > (rev 04) > 00:1f.0 ISA bridge [0601]: Intel Corporation 82801BA ISA Bridge (LPC) > [8086:2440] (rev 04) > 00:1f.1 IDE interface [0101]: Intel Corporation 82801BA IDE U100 Controller > [8086:244b] (rev 04) > 00:1f.2 USB Controller [0c03]: Intel Corporation 82801BA/BAM USB Controller > #1 [8086:2442] (rev 04) > 00:1f.3 SMBus [0c05]: Intel Corporation 82801BA/BAM SMBus Controller > [8086:2443] (rev 04) > 00:1f.4 USB Controller [0c03]: Intel Corporation 82801BA/BAM USB Controller > #1 [8086:2444] (rev 04) > 00:1f.5 Multimedia audio controller [0401]: Intel Corporation 82801BA/BAM > AC'97 Audio Controller [8086:2445] (rev 04) > 01:00.0 VGA compatible controller [0300]: nVidia Corporation NV5 [RIVA > TNT2/TNT2 Pro] [10de:0028] (rev 15) > 02:0c.0 Ethernet controller [0200]: 3Com Corporation 3c905C-TX/TX-M [Tornado] > [10b7:9200] (rev 78) > steve@smp3:~$ > > ----- > > Notice that last line of output, which shows the PCI id for the Ethernet > controller > as 10b7:9200. 10b7 identifies the vendor (3Com, in this case) and 9200 > identifies > a specific card (3c905C-TX/TX-M [Tornado]). That matches up with alias entry > > ----- > > alias: pci:v000010B7d00009200sv*sd*bc*sc*i* > > ----- > > Notice the 10B7 and the 9200 as part of the alias name. When udev discovers > this > card, it knows to load kernel module 3c59x. > > Sometimes, if you know a kernel module supports a given card, but it doesn't > have > a corresponding alias, you can add your own alias entries in a *.conf file in > /etc/modprobe.d. But be sure that the module really does support the card. > > Sometimes more than one module has matching alias entries and you will have to > blacklist one or more modules in a *.conf file in /etc/modprobe.d to prevent > the ones you don't want from loading. > > If you make any changes to files in /etc/modprobe.d, be sure to rebuild your > initial RAM file system after making changes and before rebooting. For > example, > > update-initramfs -uk $(uname -r) > > Issue the above command as root. > > -- > .''`. Stephen Powell > : :' : > `. `'` > `- > > > -- > To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org > with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org > Archive: > http://lists.debian.org/914824368.2047333.1316691555755.javamail.r...@md01.wow.synacor.com >
Thanks a lot for all your answers :) D. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/2077d6b4-fb5a-4a47-a100-57b0186d8...@gmail.com
