| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* -*- auto-fill -*- */ |
| 2 | |
| 3 | Device File System (devfs) Boot Options |
| 4 | |
| 5 | Richard Gooch <rgooch@atnf.csiro.au> |
| 6 | |
| 7 | 18-AUG-2001 |
| 8 | |
| 9 | |
| 10 | When CONFIG_DEVFS_DEBUG is enabled, you can pass several boot options |
| 11 | to the kernel to debug devfs. The boot options are prefixed by |
| 12 | "devfs=", and are separated by commas. Spaces are not allowed. The |
| 13 | syntax looks like this: |
| 14 | |
| 15 | devfs=<option1>,<option2>,<option3> |
| 16 | |
| 17 | and so on. For example, if you wanted to turn on debugging for module |
| 18 | load requests and device registration, you would do: |
| 19 | |
| 20 | devfs=dmod,dreg |
| 21 | |
| 22 | You may prefix "no" to any option. This will invert the option. |
| 23 | |
| 24 | |
| 25 | Debugging Options |
| 26 | ================= |
| 27 | |
| 28 | These requires CONFIG_DEVFS_DEBUG to be enabled. |
| 29 | Note that all debugging options have 'd' as the first character. By |
| 30 | default all options are off. All debugging output is sent to the |
| 31 | kernel logs. The debugging options do not take effect until the devfs |
| 32 | version message appears (just prior to the root filesystem being |
| 33 | mounted). |
| 34 | |
| 35 | These are the options: |
| 36 | |
| 37 | dmod print module load requests to <request_module> |
| 38 | |
| 39 | dreg print device register requests to <devfs_register> |
| 40 | |
| 41 | dunreg print device unregister requests to <devfs_unregister> |
| 42 | |
| 43 | dchange print device change requests to <devfs_set_flags> |
| 44 | |
| 45 | dilookup print inode lookup requests |
| 46 | |
| 47 | diget print VFS inode allocations |
| 48 | |
| 49 | diunlink print inode unlinks |
| 50 | |
| 51 | dichange print inode changes |
| 52 | |
| 53 | dimknod print calls to mknod(2) |
| 54 | |
| 55 | dall some debugging turned on |
| 56 | |
| 57 | |
| 58 | Other Options |
| 59 | ============= |
| 60 | |
| 61 | These control the default behaviour of devfs. The options are: |
| 62 | |
| 63 | mount mount devfs onto /dev at boot time |
| 64 | |
| 65 | only disable non-devfs device nodes for devfs-capable drivers |