On Fri, 21 Jan 2000, Venkat Swaminathan wrote:

Where would I find information about char-major-xxx, etc.? I find people saying things like "set char-major-108 off to fix your problem" and stuff like that. How do I get to know what char-major-xxx to use for serial, parallel, IDE, etc.? What is a char-major-...?

This is only My Way (tm), but when I need information on a device (char or block), I simply `ls -l /dev/* | grep $number'. For example, if I wanted information on char-major-108, I would `ls -l /dev/* | grep 108', which returns: brw-rw---- 1 root disk 2, 108 Dec 6 16:26 /dev/fd0u3520 crw-rw---- 1 root root 108, 0 Dec 6 16:26 /dev/ppp crw-rw-rw- 1 root tty 2, 108 Dec 6 16:26 /dev/ptyvc brw-rw---- 1 root disk 8, 108 Dec 6 16:26 /dev/sdg12 crw-rw-rw- 1 root tty 3, 108 Dec 6 16:26 /dev/ttyvc brw-rw---- 1 root disk 72, 108 Dec 6 16:26 c0d6p12 brw-rw---- 1 root disk 73, 108 Dec 6 16:26 c1d6p12 Examining the output above, I find that 108 is the major number (0 is the minor) for /dev/ppp, which happens to be a character device. If you had a secret decoder ring like me, this information is really easy to understand, but since you don't ;) crw-rw---- 1 root root 108, 0 Dec 6 16:26 /dev/ppp ^ ^ ^ ^ | | | | c for character, b for block major# minor# device name Some queries offer significantly more verbose output, such as `ls -l /dev/* | grep 4', which returns all devices with a 4 in the major number, minor number, or even device name. In other words, this doesn't always work, but it's a start ;). -- -=|JP|=- Jon Pennington | Atipa Linux Solutions -o) jpennington@atipa.com | http://www.atipa.com /\\ Kansas City, MO, USA | 816-241-2641 x110 _\_V -- To unsubscribe send e-mail to suse-linux-e-unsubscribe@suse.com For additional commands send e-mail to suse-linux-e-help@suse.com Also check the FAQ at http://www.suse.com/Support/Doku/FAQ/

a prolly not quite accurate description, but safe from a users veiw: devices in /dev are referenced by the kernel by their major-minor numbers. these can be found with 'ls -la'... "crw-rw---- 1 root root 108, 0 Jul 22 1999 /dev/ppp" the 108 is the major, the 0 is the minor.. the 108 is the type of device, while the minor it like the sucessive number of that class.. so basically, you an positivily identify any dev by its major-minor. where this really comes into play as a 'user', are error messages like "PANIC: unable to mount root fs 2,0" (or whatever that error is.heh) then, by looking at the major-minors in /dev, you could see that the kernel is trying to mount the floppy and could fix it by rdev'ing the kernel your trying to boot off of. anyway.. for programming info associated with the major-minor's, look at like the Coffee-HOWTO and the Serial-Programming-HOWTO, they both discuss this in alot more detail. -- ======================================================================== Rocky McGaugh Atipa Linux Solutions Linux Systems Engineer www.atipa.com rocky@smluc.org rmcgaugh@atipa.com ======================================================================== On Fri, 21 Jan 2000, Venkat Swaminathan wrote:

Where would I find information about char-major-xxx, etc.? I find people saying things like "set char-major-108 off to fix your problem" and stuff like that. How do I get to know what char-major-xxx to use for serial, parallel, IDE, etc.? What is a char-major-...?

Is the related information on the SuSE CDs? Any books?

Thanks

-venkat

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