On 07-Jul-2000 Walter Williams wrote: > So it sounds like there are files containing > pre-defined information for making /dev entries. > I would therefore conclude that it knows that > "lp3" would be a printer port and configures > it accordingly. >
files in /dev are special files. if you ls -l one: crw-rw---- 1 root audio 14, 4 Jun 23 1999 /dev/audio you see the normal permission info, who owns it, date touched, etc. But note the extra data '14, 4'. These are major and minor numbers. These numbers map into a table in the kernel. So 14,4 -> sound module. brw-rw---- 1 root disk 8, 16 Mar 3 1999 sdb 8,16 second scsi disk and so on. This file existing only means that you can try to access the device. The kernel must be configured to support a device (having the sound module) and the actual device support must be configured (what sound module? what irq?).
