Notes on Using QNX Neutrino

Removeable disks

• To mount a dos-formatted floppy, use the following command: mount -t dos /dev/fd0 /fs/floppy. You must be logged in as root to run the mount command. -t dos tells the mount command that the disk is dos-formatted. /dev/fd0 is the name of the disk's block-device file, although it may differ according to the setup (e.g. /dev/fd1 for the second floppy disk if there are two). /fs is the default directory location for mounted file systems. Any name can be given to the mounted floopy disk file system, such as a (for A: drive) or just fd0 (to match the block device filename). Use umount /fs/floppy to unmount the disk.
• To format a floppy disk, just login as root and use fdformat /dev/fd0. There are various options for this command, but the defaults are usually suitable. Note that you must then explicictly place a filesystem on it with dinit /dev/fd0. Again the default options are usually fine. Dinit may not be in your path, if not, it can be found in /sbin/ and /x86/sbin/.
• Mounting an Iomega zip disk is easier, and harder. If the disk is already in the drive at boot time, it will automatically be mounted, but if it wasn't, the disk can't be read (at least it doesn't work for me). The mount command works, but any attempt to access the disk results in a "corrupted file system detected" error message. This problem seems only to occur with FAT (MS-DOS) formatted disks. With QNX format, the disk can be mounted and used with no problems. If anyone knows how to resolve this issue, please let me know!

Supported Filesystems

• QNX can read and write to FAT and FAT32 file systems. It seems to ignore the case of all characters of the filename except the first character. It is not necessary to mount these file systems (say if you have QNX installed on a partitioned disk) since the FATx partition will be automatically mounted under /fs/hd0 (the number will increase for additional partitions).

Missing commands

The following standard Unix commands seem to be unavailable in QNX

• adduser (use passwd instead)
• groups
• chsh
• lpq (use lprq instead)
• lprm, cancel (use lprrm instead)

PCI Cards

• The devices found on the PCI bus can be listed using the pci program, which may not be in your $PATH. It is found in /usr/sbin/ and /x86/usr/sbin/.

Startup Files

• When QNX boots, the following scripts are run in this order: /etc/system/sysinit, /etc/rc.d/rc.devices, /etc/rc.d/rc.sysinit, /etc/rc.d/rc.local

Login via Serial Port

Being able to login via the serial port is a useful feature. It is especially handy when the keyboard isn't responding, or when the floppy disk and ethernet hardware aren't recognised and you need to get a file off the hard disk. You only need to do two things to activate login over the serial port.

(1) Configure the serial parameters for the port. You can do this by adding the following stty command (you may need to change the settings for your situation) to /etc/rc.d/rc.local (ensure that rc.local is run at startup, and has executable permissions) :

stty baud=115200 bits=8 stopb=1 par=none </dev/ser1

(2) Tell the terminal initialisation program tinit about the serial port. This is achieved by adding the following line to /etc/config/ttys :

ser1 "/bin/login" qansi-m on

Shell

The default (Korn) shell uses the key sequence ESC ESC for filename completion. To change this default to match the bash default (TAB), use the command bind '^I'=complete

Beware: when using the cp and mv commands, if a file exists that has the same name as the given destination name, by default they will silently overwrite the existing file.

Vim Editor

Elvis is the default vi editor. That is, the file /bin/vi is a symbolic link to /bin/elvis. Vim is a more powerful clone of vi; to make it the default vi editor, change the symbolic link to point to /usr/bin/vim with the command ln -fs /usr/bin/vim /bin/vi. You may also want to do this for the view command.

Compiling Open Sources

od is called by libtool, which itself is called by GNU configure (for teTeX at least). od on QNX is actually a link to /usr/bin/hd. hd does not support the “-x” option, which is actually an abbreviation for “-A x2” meaning two-byte hex (or just “-A x” since two bytes is the default for this format).

Content last updated: 2005-06-20