[gentoo-user] [OT] - a couple of mknod questions
Hi, I'm looking at a very small problem on my new Gentoo kernel where I get the message while booting modprobe: can't locate module /dev/rtc From googling around it appears that the recommended solution to this (comment if you disagree) is to compile enhanced rtc support into my kernel (it's not in there right now) AND to create /dev/rtc using the mknod command with a major number 10 and a minor number 135. It may be that I don't really need to create the QUESTION 1: Is this correct? mknod /dev/rtc 10 135 Or do I need to add the c option since it says make a 'character' special file? mknod /dev/rtc c 10 135 QUESTION 2: Is there a way to see the major and minor numbers, along with the type of device an existing character or block special file is once it exists in /dev? I cannot find the sort of intuitive 'lsnod' command. How does one make sure that the major minor numbers don't trample on each other? Thanks in advance, Mark -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] [OT] - a couple of mknod questions
On Tue, 9 Sep 2003, Mark Knecht wrote: Hi, I'm looking at a very small problem on my new Gentoo kernel where I get the message while booting modprobe: can't locate module /dev/rtc From googling around it appears that the recommended solution to this (comment if you disagree) is to compile enhanced rtc support into my kernel (it's not in there right now) AND to create /dev/rtc using the mknod command with a major number 10 and a minor number 135. It may be that I don't really need to create the QUESTION 1: Is this correct? mknod /dev/rtc 10 135 Or do I need to add the c option since it says make a 'character' special file? mknod /dev/rtc c 10 135 You have the command written correctly the second time. However, as Gentoo defaults to using devfs, you shouldn't have to manually create a /dev entry. But you still have the options of: 1) Compile enhanced RTC support into your kernel (or as module), 2) find what wants enhanced RTC support and don't use it, or 3) ignore the error. QUESTION 2: Is there a way to see the major and minor numbers, along with the type of device an existing character or block special file is once it exists in /dev? I cannot find the sort of intuitive 'lsnod' command. How does one make sure that the major minor numbers don't trample on each other? It's simpler than you think. 'ls -l /dev' shows you what it is. The first letter of the permissions is b for block device, c for character device, or l for symlink. If it's a symlink, then you have to look at what it links to. But then, you'll see two numbers (a, b) in the size field. This is the major, minor numbers. And if you want to create a device that doesn't exist but don't know its numbers, everything is listed in /usr/src/linux/Documentation/devices.txt (or wherever you have your kernel sources). -- Marshal Newrock, unemployed Linux user in Lansing, MI Caution: Product will be hot after heating -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] [OT] - a couple of mknod questions
On Tue, 2003-09-09 at 15:13, Marshal Newrock wrote: Or do I need to add the c option since it says make a 'character' special file? mknod /dev/rtc c 10 135 You have the command written correctly the second time. However, as Gentoo defaults to using devfs, you shouldn't have to manually create a /dev entry. But you still have the options of: 1) Compile enhanced RTC support into your kernel (or as module), 2) find what wants enhanced RTC support and don't use it, or 3) ignore the error. Thank you Marshal. This would probably explain why my last kernel (for which I somehow lost the .config file...) didn't have the problem. If I compiled in enhanced rtc support the last time, then Gentoo would have created whatever it needed in terms of /dev/rtc and there was no complaint. If that's the case, then I'll first do a new kernel and see if the messages just go away. (And I'll stick a copy of my .config on another machine as a back up...) QUESTION 2: Is there a way to see the major and minor numbers, along with the type of device an existing character or block special file is once it exists in /dev? I cannot find the sort of intuitive 'lsnod' command. How does one make sure that the major minor numbers don't trample on each other? It's simpler than you think. 'ls -l /dev' shows you what it is. The first letter of the permissions is b for block device, c for character device, or l for symlink. If it's a symlink, then you have to look at what it links to. But then, you'll see two numbers (a, b) in the size field. This is the major, minor numbers. crw-r--r--1 root root 1, 9 Dec 31 1969 urandom So this is a character special device, major number 1, minor number 9 which matches the info in devices.txt: 1 charMemory devices 1 = /dev/mem Physical memory access SNIP 9 = /dev/urandom Faster, less secure random number gen. Thanks! Mark -- [EMAIL PROTECTED] mailing list
