NuttShell (NSH)Last Updated: March 6, 2012 |
Table of Contents |
1.0 Overview |
The apps/nshlib sub-directory contains the NuttShell (NSH)
library.
This library can easily to linked to produce a NSH application (See as an example apps/nshlib).
NSH is a simple shell application for NuttX.
1.1 Console/NSH Front End |
Using settings in the configuration file, NSH may be configured to use either the serial stdin/out or a telnet connection as the console or BOTH. When NSH is started, you will see the following welcome on either console:
NuttShell (NSH) nsh>
nsh> is the NSH prompt and indicates that you may enter a command
from the console.
1.2 Command Overview |
Simple, Re-directed, and Background Commands. The NuttShell (NSH) is a simple shell application. NSH supports the following commands forms:
| Simple command: | <cmd> |
| Command with re-directed output: |
<cmd> > <file> |
| Background command: | <cmd> & |
| Re-directed background command: |
<cmd> > <file> & |
Where:
<cmd> |
is any one of the simple commands listed later. |
<file> |
is the full or relative path to any writable object in the filesystem name space (file or character driver). Such objects will be referred to simply as files throughout this document. |
nice'd Background Commands
NSH executes at the mid-priority (128). Backgrounded commands can
be made to execute at higher or lower priorities using nice:
[nice [-d <niceness>>]] <cmd> [> <file>|>> <file>] [&]
Where <niceness> is any value between -20 and 19 where lower
(more negative values) correspond to higher priorities.
The default niceness is 10.
1.3 Conditional Command Execution |
An if-then[-else]-fi construct is also supported in order to
support conditional execution of commands. This works from the
command line but is primarily intended for use within NSH scripts
(see the sh commnd). The syntax is as follows:
if <cmd> then [sequence of <cmd>] else [sequence of <cmd>] fi
1.4 Built-In Variables |
$? |
The result of the last simple command execution. On backgrounded commands, this variable holds only the result of spawning the background command. |
1.5 Current Working Directory |
cd and pwd.
All path arguments to commands may be either an absolute path or a
path relative to the current working directory. The current working
directory is set using the cd command and can be queried either
by using the pwd command or by
using the echo $PWD
command.
1.6 Environment Variables |
Environment Variables:
PWD | The current working directory |
OLDPWD | The previous working directory |
1.7 NSH Start-Up Scrip |
NSH Start-Up Script.
NSH supports options to provide a start up script for NSH. In general
this capability is enabled with CONFIG_NSH_ROMFSETC, but has
several other related configuration options as described with the
NSH-specific configuration settings.
This capability also depends on:
CONFIG_DISABLE_MOUNTPOINT not set
CONFIG_NFILE_DESCRIPTORS < 4
CONFIG_FS_ROMFS enabled
Default Start-Up Behavior. The implementation that is provided is intended to provide great flexibility for the use of Start-Up files. This paragraph will discuss the general behavior when all of the configuration options are set to the default values.
In this default case, enabling CONFIG_NSH_ROMFSETC will cause
NSH to behave as follows at NSH startup time:
`--init.d/
`-- rcS
/etc, resulting in:
|--dev/
| `-- ram0
`--etc/
`--init.d/
`-- rcS
# Create a RAMDISK and mount it at XXXRDMOUNTPOUNTXXX mkrd -m 1 -s 512 1024 mkfatfs /dev/ram1 mount -t vfat /dev/ram1 /tmp
/etc/init.d/rcS at start-up (before the
first NSH prompt. After execution of the script, the root FS will look
like:
|--dev/ | |-- ram0 | `-- ram1 |--etc/ | `--init.d/ | `-- rcS `--tmp/
Modifying the ROMFS Image.
The contents of the /etc directory are retained in the file apps/nshlib/nsh_romfsimg.h OR, if CONFIG_NSH_ARCHROMFS is defined, include/arch/board/rcs.template).
In order to modify the start-up behavior, there are three things to study:
CONFIG_NSH_ROMFSETC configuration options
discussed with the other NSH-specific configuration settings.
tools/mkromfsimg.sh Script.
The script tools/mkromfsimg.sh creates nsh_romfsimg.h.
It is not automatically executed. If you want to change the
configuration settings associated with creating and mounting
the /tmp directory, then it will be necessary to re-generate
this header file using the tools/mkromfsimg.sh script.
The behavior of this script depends upon three things:
genromfs tool (available from http://romfs.sourceforge.net).
apps/nshlib/rcS.template
(OR, if CONFIG_NSH_ARCHROMFS is defined include/arch/board/rcs.template.
rcS.template.
The file apps/nshlib/rcS.template contains the general form
of the rcS file; configured values are plugged into this
template file to produce the final rcS file.
NOTE:
apps/nshlib/rcS.template generates the standard, default nsh_romfsimg.h file.
If CONFIG_NSH_ARCHROMFS is defined in the NuttX configuration file, then a custom, board-specific nsh_romfsimg.h file residing in configs/<board>/include will be used.
NOTE when the OS is configured, include/arch/board will be linked to configs/<board>/include.
All of the startup-behavior is contained in rcS.template. The
role of mkromfsimg.sh is to (1) apply the specific configuration
settings to rcS.template to create the final rcS, and (2) to
generate the header file nsh_romfsimg.h containg the ROMFS
file system image.
2.0 Commands |
2.1 Evaluate Expression (test) |
Command Syntax:
[ <expression> ] test <expression>
Synopsis.
These are two alternative forms of the same command. They support
evaluation of a boolean expression which sets $?.
This command is used most frequently as the conditional command following the
if in the if-then[-else]-fi construct.
Expression Syntax:
expression = simple-expression | !expression | expression -o expression | expression -a expression
simple-expression = unary-expression | binary-expression
unary-expression = string-unary | file-unary
string-unary = -n string | -z string
file-unary = -b file | -c file | -d file | -e file | -f file | -r file | -s file | -w file
binary-expression = string-binary | numeric-binary
string-binary = string = string | string == string | string != string
numeric-binary = integer -eq integer | integer -ge integer | integer -gt integer | integer -le integer | integer -lt integer | integer -ne integer
2.2 Concatenate Files (cat) |
Command Syntax:
cat<path>[<path>[<path>...]]
Synopsis.
This command copies and concatentates all of the files at <path>
to the console (or to another file if the output is redirected).
2.3 Change Current Working Directory (cd) |
Command Syntax:
cd [<dir-path>|-|~|..]
Synopsis.
Changes the current working directory (PWD). Also sets the
previous working directory environment variable (OLDPWD).
Forms:
cd <dir-path> |
sets the current working directory to <dir-path>. |
cd - |
sets the current working directory to the previous
working directory ($OLDPWD).
Equivalent to cd $OLDPWD. |
cd or cd ~ |
set the current working directory to the 'home'
directory. The home directory can be configured by setting
CONFIG_LIB_HOMEDIR in the configuration file. The default
home directory is /. |
cd .. |
sets the current working directory to the parent directory. |
2.4 Copy Files (cp) |
Command Syntax:
cp <source-path> <dest-path>
Synopsis.
Copy of the contents of the file at <source-path> to the location
in the filesystem indicated by <dest-path>.
2.5 Show or set the date and time (date) |
Command Syntax:
date [-s "MMM DD HH:MM:SS YYYY"]
Synopsis.
Show or set the current date and time.
This command is only supported if the platform supported RTC hardware (CONFIG_RTC=y).
Only one format is used both on display and when setting the date/time:
MMM DD HH:MM:SS YYYY. For example,
data -s "Sep 1 11:30:00 2011"
24-hour time is used.
2.6 Copy and Convert Files (dd) |
Command Syntax:
dd if=<infile> of=<outfile> [bs=<sectsize>] [count=<sectors>] [skip=<sectors>]
Synopsis. Copy blocks from <infile> to <outfile>. <infile> or <outfile> may be the path to a standard file, a character device, or a block device. Examples follow:
nsh> ls -l /dev /dev: crw-rw-rw- 0 zero nsh> dd if=/dev/zero of=/tmp/zeros bs=64 count=16 nsh> ls -l /tmp /tmp: -rw-rw-rw- 1024 ZEROS
nsh> ls -l /dev /dev: brw-rw-rw- 0 ram0 crw-rw-rw- 0 zero nsh> dd if=/dev/zero of=/dev/ram0
nsh> ls -l /dev /dev: crw-rw-rw- 0 null brw-rw-rw- 0 ram0 nsh> dd if=/dev/ram0 of=/dev/null
2.7 Echo Strings and Variables (echo) |
Command Syntax:
echo [<string|$name> [<string|$name>...]]
Synopsis. Copy the sequence of strings and expanded environment variables to console output (or to a file if the output is re-directed).
2.8 Execute User Code (exec) |
Command Syntax:
exec <hex-address>
Synopsis.
Execute the user logic at address <hex-address>. NSH will pause
until the execution unless the user logic is executed in background
via exec <hex-address> &.
2.9 Exit NSH (exit) |
Command Syntax:
exit
Synopsis.
Exit NSH. Only useful for the serial front end if you have started some other tasks (perhaps
using the exec command) and you would like to have NSH out of the
way. For the telnet front-end, exit terminates the telenet session.
2.10 Show Memory Manager Status (free) |
Command Syntax:
free
Synopsis. Show the current state of the memory allocator. For example,
nsh> free
total used free largest
Mem: 4194288 1591552 2602736 2601584
nsh>
Where:
total |
This is the total size of memory allocated for use by malloc in bytes. |
used |
This is the total size of memory occupied by chunks handed out by malloc. |
free |
This is the total size of memory occupied by free (not in use) chunks. |
largest |
Size of the largest free (not in use) chunk. |
2.11 Get File Via TFTP (get) |
Command Syntax:
get [-b|-n] [-f <local-path>] -h <ip-address> <remote-path>
Synopsis.
Copy the file at <remote-address> from the host whose IP address is
identified by <ip-address>.
Other options:
-f <local-path> |
The file will be saved relative to the current working directory
unless <local-path> is provided.
|
-b|-n |
Selects either binary ("octect") or test ("netascii") transfer mode. Default: text. |
2.12 Show Usage Command Usage (help) |
Command Syntax:
help
Synopsis. Presents summary information about each command to console.
2.13 Show Network Configuration (ifconfig) |
Command Syntax:
ifconfig [nic_name [ip_address]]
Synopsis.
Two forms of the ifconfigcommand are supported:
With one or no arguments, ifconfig will shows the
current configuration of the network and, perhaps, the status of ethernet
device:
ifconfig ifconfig [nic_name]
As an example:
nsh> ifconfig
eth0 HWaddr 00:18:11:80:10:06
IPaddr:10.0.0.2 DRaddr:10.0.0.1 Mask:255.255.255.0
If uIP statistics are enabled (CONFIG_NET_STATISTICS), then
this command will also show the detailed state of uIP.
If both the network interface name and an IP address are supplied as arguments,
then ifconfig will set the address of the ethernet device:
ifconfig nic_name ip_address
2.14 Send a signal to a task (kill) |
kill -<signal> <pid>
Synopsis. Send the <signal> to the task identified by <pid>.
nsh> mkfifo /dev/fifo
nsh> cat /dev/fifo &
cat [2:128]
nsh> ps
PID PRI SCHD TYPE NP STATE NAME
0 0 FIFO TASK READY Idle Task()
1 128 FIFO TASK RUNNING init()
2 128 FIFO PTHREAD WAITSEM (51ea50)
nsh> kill -9 2
nsh: cat: open failed: 4
nsh> ps
PID PRI SCHD TYPE NP STATE NAME
0 0 FIFO TASK READY Idle Task()
1 128 FIFO TASK RUNNING init()
nsh>
NOTE:
NuttX does not support a FULL POSIX signalling system.
Standard signals like SIGCHLD, SIGINTR, SIGKILL, etc. do not exist in NuttX and sending those signal may not have the result that you expect.
Rather, NuttX supports only what are referred to as POSIX real-time signals.
These signals may be used to communicate with running tasks, may be use to waiting waiting tasks, etc.
But, as an example, kill -9 (SIGKILL) will not terminate a task.
2.15 Setup/teardown the Loop Device (losetup) |
Command Syntax 1:
losetup [-o] [-r] <dev-path> <file-path>
Synopsis.
Setup the loop device at <dev-path> to access the file at <file-path> as a block device.
In the following example a 256Kb file is created (dd) and losetup is
used to make the file accessible as a block device.
A FAT file system is created (mkfatfs) and mounted (mount).
Files can then be managed on the loop-mounted file.
nsh> dd if=/dev/zero of=/tmp/image bs=512 count=512 nsh> ls -l /tmp /tmp: -rw-rw-rw- 262144 IMAGE nsh> losetup /dev/loop0 /tmp/image nsh> ls -l /dev /dev: brw-rw-rw- 0 loop0 nsh> mkfatfs /dev/loop0 nsh> mount -t vfat /dev/loop0 /mnt/example nsh> ls -l /mnt ls -l /mnt /mnt: drw-rw-rw- 0 example/ nsh> echo "This is a test" >/mnt/example/atest.txt nsh> ls -l /mnt/example /mnt/example: -rw-rw-rw- 16 ATEST.TXT nsh> cat /mnt/example/atest.txt This is a test nsh>
Command Syntax 2:
losetup d <dev-path>
Synopsis. Teardown the setup for the loop device at <dev-path>.
2.16 List Directory Contents (ls) |
Command Syntax:
ls [-lRs] <dir-path>
Synopsis.
Show the contents of the directory at <dir-path>. NOTE:
<dir-path> must refer to a directory and no other filesystem
object.
Options:
-R |
Show the constents of specified directory and all of its sub-directories. |
-s |
Show the size of the files along with the filenames in the listing |
-l |
Show size and mode information along with the filenames in the listing. |
2.17 Access Memory (mb, mh, and mw) |
Command Syntax:
mb <hex-address>[=<hex-value>][ <hex-byte-count>] mh <hex-address>[=<hex-value>][ <hex-byte-count>] mw <hex-address>[=<hex-value>][ <hex-byte-count>]
Synopsis. Access memory using byte size access (mb), 16-bit accesses (mh), or 32-bit access (mw). In each case,
<hex-address>. |
Specifies the address to be accessed. The current value at that address will always be read and displayed. |
<hex-address>=<hex-value>. |
Read the value, then write <hex-value>
to the location.
|
<hex-byte-count>. |
Perform the mb, mh, or mw operation on a total
of <hex-byte-count> bytes, increment the <hex-address> appropriately
after each access
|
Example:
nsh> mh 0 16 0 = 0x0c1e 2 = 0x0100 4 = 0x0c1e 6 = 0x0110 8 = 0x0c1e a = 0x0120 c = 0x0c1e e = 0x0130 10 = 0x0c1e 12 = 0x0140 14 = 0x0c1e nsh>
2.18 Show Current Tasks and Threads (ps) |
Command Syntax:
ps
Synopsis. Show the currently active threads and tasks. For example,
nsh> ps
PID PRI SCHD TYPE NP STATE NAME
0 0 FIFO TASK READY Idle Task()
1 128 RR TASK RUNNING init()
2 128 FIFO TASK WAITSEM nsh_telnetmain()
3 100 RR PTHREAD WAITSEM <pthread>(21)
nsh>
2.19 Create a Directory (mkdir) |
Command Syntax:
mkdir <path>
Synopsis.
Create the directory at <path>.
All components of of <path> except the final directory name must exist on a mounted file
system; the final directory must not.
Limited to Mounted File Systems.
Recall that NuttX uses a pseudo filesystem for its root file
system.
The mkdir command can only be used to create directories in volumes set up with the
mount command; it cannot be used to create directories in the pseudo filesystem.
Example:
nsh> mkdir /mnt/fs/tmp nsh> ls -l /mnt/fs /mnt/fs: drw-rw-rw- 0 TESTDIR/ drw-rw-rw- 0 TMP/ nsh>
2.20 Create a FAT Filesystem (mkfatfs) |
Command Syntax:
mkfatfs <path>
Synopsis.
Format a fat file system on the block device specified by <path>.
NSH provides this command to access the mkfatfs() NuttX API.
This block device must reside in the NuttX pseudo filesystem and
must have been created by some call to register_blockdriver() (see include/nuttx/fs.h).
2.21 Create a FIFO (mkfifo) |
Command Syntax:
mkfifo <path>
Synopsis.
Creates a FIFO character device anywhere in the pseudo file system, creating
whatever psuedo directories that may be needed to complete the <path>.
By convention, however, device drivers are place in the standard /dev directory.
After it is created, the FIFO device may be used as any other device driver.
NSH provides this command to access the mkfifo() NuttX API.
Example
nsh> ls -l /dev /dev: crw-rw-rw- 0 console crw-rw-rw- 0 null brw-rw-rw- 0 ram0 nsh> mkfifo /dev/fifo nsh> ls -l /dev ls -l /dev /dev: crw-rw-rw- 0 console crw-rw-rw- 0 fifo crw-rw-rw- 0 null brw-rw-rw- 0 ram0 nsh>
2.22 Create a RAMDISK (mkrd) |
Command Syntax:
mkrd [-m <minor>] [-s <sector-size>] <nsectors>
Synopsis.
Create a ramdisk consisting of <nsectors>, each of size
<sector-size> (or 512 bytes if <sector-size> is not specified.
The ramdisk will be registered as /dev/ram<n> (if <n> is not
specified, mkrd will attempt to register the ramdisk as /dev/ram0.
Example
nsh> ls /dev /dev: console null ttyS0 ttyS1 nsh> mkrd 1024 nsh> ls /dev /dev: console null ram0 ttyS0 ttyS1 nsh>
Once the ramdisk has been created, it may be formatted using
the mkfatfs command and mounted using the mount command.
Example
nsh> mkrd 1024 nsh> mkfatfs /dev/ram0 nsh> mount -t vfat /dev/ram0 /tmp nsh> ls /tmp /tmp: nsh>
2.23 Mount a File System (mount) |
Command Syntax:
mount -t <fstype> <block-device> <dir-path>
Synopsis. The 'm ount' command mounts a file system in the NuttX psuedo filesystem. 'mount' performs a three way associating, binding:
<fstype>' option identifies the type of
file system that has been formatted on the <block-device>.
As of this writing, vfat is the only supported value for <fstype>
<block-device> argument is the full or relative
path to a block driver inode in the pseudo filesystem.
By convention, this is a name under the /dev sub-directory.
This <block-device> must have been previously formatted with the same file system
type as specified by <fstype>
<dir-path>, is the location in the
pseudo filesystem where the mounted volume will appear.
This mount point can only reside in the NuttX pseudo filesystem.
By convention, this mount point is a subdirectory under /mnt.
The mount command will create whatever psuedo directories that may be needed to complete the
full path but the full path must not already exist.
After the volume has been mounted in the NuttX pseudo filesystem, it may be access in the same way as other objects in thefile system.
Example
nsh> ls -l /dev /dev: crw-rw-rw- 0 console crw-rw-rw- 0 null brw-rw-rw- 0 ram0 nsh> ls /mnt nsh: ls: no such directory: /mnt nsh> mount -t vfat /dev/ram0 /mnt/fs nsh> ls -l /mnt/fs/testdir /mnt/fs/testdir: -rw-rw-rw- 15 TESTFILE.TXT nsh> echo "This is a test" >/mnt/fs/testdir/example.txt nsh> ls -l /mnt/fs/testdir /mnt/fs/testdir: -rw-rw-rw- 15 TESTFILE.TXT -rw-rw-rw- 16 EXAMPLE.TXT nsh> cat /mnt/fs/testdir/example.txt This is a test nsh>
2.24 Check Network Peer (ping) |
Command Syntax:
ping [-c <count>] [-i <interval>] <ip-address>
Synopsis. Test the network communication with a remote peer. Example,
nsh> ping 10.0.0.1 PING 10.0.0.1 56 bytes of data 56 bytes from 10.0.0.1: icmp_seq=1 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=2 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=3 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=4 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=5 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=6 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=7 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=8 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=9 time=0 ms 56 bytes from 10.0.0.1: icmp_seq=10 time=0 ms 10 packets transmitted, 10 received, 0% packet loss, time 10190 ms nsh>
2.25 Send File Via TFTP (put) |
Command Syntax:
put [-b|-n] [-f <remote-path>] -h <ip-address> <local-path>
Synopsis.
Copy the file at <local-address> to the host whose IP address is
identified by <ip-address>.
Other options:
-f <remote-path> |
The file will be saved relative with the same name on the host
unless <remote-path> is provided.
|
-b|-n |
Selects either binary ("octect") or test ("netascii") transfer mode. Default: text. |
2.26 Show Current Working Directory (pwd) |
Command Syntax:
pwd
Synopsis. Show the current working directory.
nsh> cd /dev nsh> pwd /dev nsh>
nsh> echo $PWD /dev nsh>
2.27 Remove a File (rm) |
Command Syntax:
rm <file-path>
Synopsis.
Remove the specified <file-path> name from the mounted file system.
Recall that NuttX uses a pseudo filesystem for its root file
system.
The rm command can only be used to remove (unlink) files in volumes set up with the
mount command;
it cannot be used to remove names in the pseudo filesystem.
Example:
nsh> ls /mnt/fs/testdir /mnt/fs/testdir: TESTFILE.TXT EXAMPLE.TXT nsh> rm /mnt/fs/testdir/example.txt nsh> ls /mnt/fs/testdir /mnt/fs/testdir: TESTFILE.TXT nsh>
2.28 Remove a Directory (rmdir) |
Command Syntax:
rmdir <dir-path>
Synopsis.
Remove the specified <dir-path> directory from the mounted file system.
Recall that NuttX uses a pseudo filesystem for its root file
system.
The rmdir command can only be used to remove directories from volumes set up with the
mount command;
it cannot be used to remove directories from the pseudo filesystem.
Example:
nsh> mkdir /mnt/fs/tmp nsh> ls -l /mnt/fs /mnt/fs: drw-rw-rw- 0 TESTDIR/ drw-rw-rw- 0 TMP/ nsh> rmdir /mnt/fs/tmp nsh> ls -l /mnt/fs /mnt/fs: drw-rw-rw- 0 TESTDIR/ nsh>
2.29 Set an Environment Variable (set) |
Command Syntax:
set <name> <value>
Synopsis.
Set the environment variable <name> to the string <value>.
For example,
nsh> echo $foobar nsh> set foobar foovalue nsh> echo $foobar foovalue nsh>
2.30 Execute an NSH Script (sh) |
Command Syntax:
sh <script-path>
Synopsis.
Execute the sequence of NSH commands in the file referred
to by <script-path>.
2.31 Wait for Seconds (sleep) |
Command Syntax:
sleep <sec>
Synopsis.
Pause execution (sleep) for <sec> seconds.
2.32 Unmount a File System (umount) |
Command Syntax:
umount <dir-path>
Synopsis.
Un-mount the file system at mount point <dir-path>.
The umount command can only be used to un-mount volumes previously mounted using
mount command.
Example:
nsh> ls /mnt/fs /mnt/fs: TESTDIR/ nsh> umount /mnt/fs nsh> ls /mnt/fs /mnt/fs: nsh: ls: no such directory: /mnt/fs nsh>
2.33 Unset an Environment Variable (unset) |
Command Syntax:
unset <name>
Synopsis.
Remove the value associated with the environment variable
<name>. Example:
nsh> echo $foobar foovalue nsh> unset foobar nsh> echo $foobar nsh>
2.34 Wait for Microseconds (usleep) |
Command Syntax:
usleep <usec>
Synopsis.
Pause execution (sleep) of <usec> microseconds.
| 2.35 Get File Via HTTP (wget) |
Command Syntax:
wget [-o <local-path>] <url>
Synopsis.
Use HTTP to copy the file at <url> to the current directory.
Options:
-o <local-path> |
The file will be saved relative to the current working directory
and with the same name as on the HTTP server unless <local-path> is provided.
|
2.36 Hexadecimal dump (xd) |
Command Syntax:
xd <hex-address> <byte-count>
Synopsis.
Dump <byte-count> bytes of data from address <hex-address>.
Example:
nsh> xd 410e0 512 Hex dump: 0000: 00 00 00 00 9c 9d 03 00 00 00 00 01 11 01 10 06 ................ 0010: 12 01 11 01 25 08 13 0b 03 08 1b 08 00 00 02 24 ....%..........$ ... 01f0: 08 3a 0b 3b 0b 49 13 00 00 04 13 01 01 13 03 08 .:.;.I.......... nsh>
3.0 Configuration Settings |
The availability of the above commands depends upon features that may or may not be enabled in the NuttX configuration file. The following table indicates the dependency of each command on NuttX configuration settings. General configuration settings are discussed in the NuttX Porting Guide. Configuration settings specific to NSH as discussed at the bottom of this document.
Note that in addition to general NuttX configuation settings, each NSH command can be individually disabled via the settings in the rightmost column. All of these settings make the configuration of NSH potentially complex but also allow it to squeeze into very small memory footprints.
3.1 Command Dependencies on Configuration Settings |
Table. Command Dependencies on Configuration Settings
| Command | Depends on Configuration | Can Be Disabled with |
|---|---|---|
[ |
!CONFIG_NSH_DISABLESCRIPT |
CONFIG_NSH_DISABLE_TEST |
cat |
CONFIG_NFILE_DESCRIPTORS > 0 |
CONFIG_NSH_DISABLE_CAT |
cd |
!CONFIG_DISABLE_ENVIRON && CONFIG_NFILE_DESCRIPTORS > 0 |
CONFIG_NSH_DISABLE_CD |
cp |
CONFIG_NFILE_DESCRIPTORS > 0 |
CONFIG_NSH_DISABLE_CP |
date |
!CONFIG_DISABLE_CLOCK && CONFIG_RTC |
CONFIG_NSH_DISABLE_DATE |
dd |
CONFIG_NFILE_DESCRIPTORS > 0 |
CONFIG_NSH_DISABLE_DD |
echo |
CONFIG_NSH_DISABLE_ECHO |
|
exec |
CONFIG_NSH_DISABLE_EXEC |
|
exit |
CONFIG_NSH_DISABLE_EXIT |
|
free |
CONFIG_NSH_DISABLE_FREE |
|
get |
CONFIG_NET && CONFIG_NET_UDP &&
CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_NET_BUFSIZE >= 5581 |
CONFIG_NSH_DISABLE_GET |
help |
CONFIG_NSH_DISABLE_HELP |
|
ifconfig |
CONFIG_NET |
CONFIG_NSH_DISABLE_IFCONFIG |
kill |
!CONFIG_DISABLE_SIGNALS |
CONFIG_NSH_DISABLE_KILL |
losetup |
!CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 |
CONFIG_NSH_DISABLE_LOSETUP |
ls |
CONFIG_NFILE_DESCRIPTORS > 0 |
CONFIG_NSH_DISABLE_LS |
mb,mh,mw |
CONFIG_NSH_DISABLE_MB,CONFIG_NSH_DISABLE_MH,CONFIG_NSH_DISABLE_MW
|
|
mkdir |
!CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_WRITABLE4 |
CONFIG_NSH_DISABLE_MKDIR |
mkfatfs |
!CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_FAT |
CONFIG_NSH_DISABLE_MKFATFS |
mkfifo |
CONFIG_NFILE_DESCRIPTORS > 0 |
CONFIG_NSH_DISABLE_MKFIFO |
mkrd |
!CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_WRITABLE4 |
CONFIG_NSH_DISABLE_MKRD |
mount |
!CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_READABLE3 |
CONFIG_NSH_DISABLE_MOUNT |
ping |
CONFIG_NET && CONFIG_NET_ICMP &&
CONFIG_NET_ICMP_PING && !CONFIG_DISABLE_CLOCK &&
!CONFIG_DISABLE_SIGNALS |
CONFIG_NSH_DISABLE_PING |
ps |
CONFIG_NSH_DISABLE_PS |
|
put |
CONFIG_NET && CONFIG_NET_UDP &&
CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_NET_BUFSIZE >= 5581,2 |
CONFIG_NSH_DISABLE_PUT |
pwd |
!CONFIG_DISABLE_ENVIRON && CONFIG_NFILE_DESCRIPTORS > 0 |
CONFIG_NSH_DISABLE_PWD |
rm |
!CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_WRITABLE4 |
CONFIG_NSH_DISABLE_RM |
rmdir |
!CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_WRITABLE4 |
CONFIG_NSH_DISABLE_RMDIR |
set |
!CONFIG_DISABLE_ENVIRON |
CONFIG_NSH_DISABLE_SET |
sh |
CONFIG_NFILE_DESCRIPTORS > 0 && |
CONFIG_NSH_DISABLE_SH |
sleep |
!CONFIG_DISABLE_SIGNALS |
CONFIG_NSH_DISABLE_SLEEP |
test |
!CONFIG_NSH_DISABLESCRIPT |
CONFIG_NSH_DISABLE_TEST |
umount |
!CONFIG_DISABLE_MOUNTPOINT && CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_FS_READABLE3 |
CONFIG_NSH_DISABLE_UMOUNT |
unset |
!CONFIG_DISABLE_ENVIRON |
CONFIG_NSH_DISABLE_UNSET |
usleep |
!CONFIG_DISABLE_SIGNALS |
CONFIG_NSH_DISABLE_USLEEP |
wget |
CONFIG_NET && CONFIG_NET_TCP &&
CONFIG_NFILE_DESCRIPTORS > 0 |
CONFIG_NSH_DISABLE_WGET |
xd |
CONFIG_NSH_DISABLE_XD |
1
Because of hardware padding, the actual required packet size may be larger
2
Special TFTP server start-up optionss will probably be required to permit
creation of files for the correct operation of the put command.
3
CONFIG_FS_READABLE is not a user configuration but is set automatically
if any readable filesystem is selected. At present, this is either CONFIG_FS_FAT
or CONFIG_FS_ROMFS.
4
CONFIG_FS_WRITABLE is not a user configuration but is set automatically
if any writable filesystem is selected. At present, this is only CONFIG_FS_FAT.
3.2 NSH-Specific Configuration Settings |
The behavior of NSH can be modified with the following settings in
the configs/<board-name>/defconfig file:
| Configuration | Description |
|---|---|
CONFIG_NSH_BUILTIN_APPS |
Support external registered, "named" applications that can be executed from the NSH command line (see apps/README.txt for more information). |
CONFIG_NSH_FILEIOSIZE |
Size of a static I/O buffer used for file access (ignored if there is no filesystem). Default is 1024. |
CONFIG_NSH_STRERROR |
strerror(errno) makes more readable output but strerror() is very large and will not be used unless this setting is y |
CONFIG_NSH_LINELEN |
The maximum length of one command line and of one output line. Default: 80 |
CONFIG_NSH_NESTDEPTH |
The maximum number of nested if-then[-else]-fi sequences that
are permissable. Default: 3
|
CONFIG_NSH_DISABLESCRIPT |
This can be set to y to suppress support for scripting. This
setting disables the sh, test, and [ commands and the
if-then[-else]-fi construct. This would only be set on systems
where a minimal footprint is a necessity and scripting is not.
|
CONFIG_NSH_DISABLEBG |
This can be set to y to suppress support for background
commands. This setting disables the nice command prefix and
the & command suffix. This would only be set on systems
where a minimal footprint is a necessity and background command execution is not.
|
CONFIG_NSH_MMCSDMINOR |
If the architecture supports an MMC/SD slot and if the NSH
architecture specific logic is present, this option will provide
the MMC/SD minor number, i.e., the MMC/SD block driver will
be registered as /dev/mmcsdN where N is the minor number.
Default is zero.
|
CONFIG_NSH_ROMFSETC |
Mount a ROMFS filesystem at /etc and provide a startup script
at /etc/init.d/rcS. The default startup script will mount
a FAT FS RAMDISK at /tmp but the logic is
easily extensible.
|
CONFIG_NSH_CONSOLE |
If
Normally, the serial console device is a UART and RS-232 interface.
However, if
|
CONFIG_NSH_CONDEV |
If CONFIG_NSH_CONSOLE is set to y, then CONFIG_NSH_CONDEV
may also be set to select the serial device used to support the NSH console.
This should be set to the quoted name of a readable/write-able character driver such as:
CONFIG_NSH_CONDEV="/dev/ttyS1".
This is useful, for example, to separate the NSH command line from the system console
when the system console is used to provide debug output.
Default: stdin and stdout (probably "/dev/console")
/dev/console is used for a user interface,
(1) linefeeds (\n) will not be expanded to carriage return / linefeeds (\r\n).
You will need to configure your terminal program to account for this.
And (2) input is not automatically echoed so you will have to turn local echo on.
|
CONFIG_NSH_TELNET |
If CONFIG_NSH_TELNET is set to y, then a TELENET
server front-end is selected. When this option is provided,
you may log into NuttX remotely using telnet in order to
access NSH.
|
CONFIG_NSH_ARCHINIT |
Set CONFIG_NSH_ARCHINIT if your board provides architecture
specific initialization via the board-specific function nsh_archinitialize().
This function will be called early in NSH initialization to allow board logic to
do such things as configure MMC/SD slots.
|
If Telnet is selected for the NSH console, then we must configure the resources used by the Telnet daemon and by the Telnet clients.
| Configuration | Description |
|---|---|
CONFIG_NSH_TELNETD_PORT |
The telnet daemon will listen on this TCP port number for connections. Default: 23 |
CONFIG_NSH_TELNETD_DAEMONPRIO |
Priority of the Telnet daemon.
Default: SCHED_PRIORITY_DEFAULT
|
CONFIG_NSH_TELNETD_DAEMONSTACKSIZE |
Stack size allocated for the Telnet daemon. Default: 2048 |
CONFIG_NSH_TELNETD_CLIENTPRIO |
Priority of the Telnet client.
Default: SCHED_PRIORITY_DEFAULT
|
CONFIG_NSH_TELNETD_CLIENTSTACKSIZE |
Stack size allocated for the Telnet client. Default: 2048 |
One or both of CONFIG_NSH_CONSOLE and CONFIG_NSH_TELNET
must be defined. If CONFIG_NSH_TELNET is selected, then there some
other configuration settings that apply:
| Configuration | Description |
|---|---|
CONFIG_NET=y |
Of course, networking must be enabled. |
CONFIG_NSOCKET_DESCRIPTORS |
And, of course, you must allocate some socket descriptors. |
CONFIG_NET_TCP=y |
TCP/IP support is required for telnet (as well as various other TCP-related configuration settings). | CONFIG_NSH_IOBUFFER_SIZE |
Determines the size of the I/O buffer to use for sending/ receiving TELNET commands/reponses |
CONFIG_NSH_DHCPC |
Obtain the IP address via DHCP. |
CONFIG_NSH_IPADDR |
If CONFIG_NSH_DHCPC is NOT set, then the static IP
address must be provided.
|
CONFIG_NSH_DRIPADDR |
Default router IP address |
CONFIG_NSH_NETMASK |
Network mask |
CONFIG_NSH_NOMAC |
Set if your ethernet hardware has no built-in MAC address. If set, a bogus MAC will be assigned. |
If you use DHCPC, then some special configuration network options are required. These include:
| Configuration | Description |
|---|---|
CONFIG_NET=y |
Of course, networking must be enabled. |
CONFIG_NSOCKET_DESCRIPTORS |
And, of course, you must allocate some socket descriptors. |
CONFIG_NET_UDP=y |
UDP support is required for DHCP (as well as various other UDP-related configuration settings). |
CONFIG_NET_BROADCAST=y |
UDP broadcast support is needed. |
CONFIG_NET_BUFSIZE=650 (or larger) |
Per RFC2131 (p. 9), the DHCP client must be prepared to receive DHCP messages of up to 576 bytes (excluding Ethernet, IP, or UDP headers and FCS). |
If CONFIG_NSH_ROMFSETC is selected, then the following additional
configuration setting apply:
| Configuration | Description |
|---|---|
CONFIG_NSH_ARCHROMFS |
May be defined to specify an alternative ROMFS image that can be found at configs/<board>/include/nsh_romfsimg.h.
|
CONFIG_NSH_ROMFSMOUNTPT |
The default mountpoint for the ROMFS volume is "/etc", but that
can be changed with this setting. This must be a absolute path
beginning with '/' and enclosed in quotes.
|
CONFIG_NSH_INITSCRIPT |
This is the relative path to the startup script within the mountpoint.
The default is "init.d/rcS". This is a relative path and must not
start with '/' but must be enclosed in quotes.
|
CONFIG_NSH_ROMFSDEVNO |
This is the minor number of the ROMFS block device. The default is
'0' corresponding to /dev/ram0.
|
CONFIG_NSH_ROMFSSECTSIZE |
This is the sector size to use with the ROMFS volume. Since the default volume is very small, this defaults to 64 but should be increased if the ROMFS volume were to be become large. Any value selected must be a power of 2. |
When the default rcS file used when CONFIG_NSH_ROMFSETC is
selected, it will mount a FAT FS under /tmp. The following selections
describe that FAT FS.
| Configuration | Description |
|---|---|
CONFIG_NSH_FATDEVNO |
This is the minor number of the FAT FS block device. The default is
'1' corresponding to /dev/ram1.
|
CONFIG_NSH_FATSECTSIZE |
This is the sector size use with the FAT FS. Default is 512. |
Index |
|
execexitfreegethelpif-then[-else]-fiifconfigkilllosetupmbmhmwmkdirmkfatfsmkfifomkrdmountniceOLDPWDpingpsputpwdPWDrmrmdirsetshsleeptestumountunsetusleepwgetxd |