Environment variables

Environment variables are used to control the behavior of PMON2000 and pass information between programs. Some variables affect console input and output, other controls the default settings for commands while some controls the boot process such as boot device and automatic startup.

To set, change or clear variables the set, unset, eset and resetenv commands are used.

Environment variables are usually stored in the targets NVRAM. The maximum length of an environment variable is 254 characters, name and value together.

PMON2000 variables

The following variables are used by PMON2000 to control its basic behavior:

Variable Default Constraints Description
prompt PMON> <max string> This variable can be used to change the standard PMON Shell prompt. The meta character !, when used, will be replaced with the command sequence number.
moresize 10 <integer> This variable specifies how many lines to display during screen-at-a-time display. See the more command.
inalpha hex [hex symbol] This variable selects whether strings starting with the ASCII characters a, b, c, d, e, and f are interpreted as symbols or hexadecimal numbers. See expressions.
inbase 16 [auto 8 10 16] This variable selects the default input base for numeric values. Users can input octal, decimal, or hexadecimal numbers by changing this variable. See expressions.
datasize -b [-b -h -w -d] This variable controls whether data is displayed in byte, half-word, word or quad groups. See the d command.
rptcmd trace [off on trace] When set to "on," the previous command is repeated when the user enters an empty line. When set to "trace" only trace commands will be repeated. See the sh command.
trabort ^K <char> This variable selects the character that terminates transparent mode and returns to command mode. See the tr command.
TZ <none> <string> When set to GMT+-<n> the time displayed by the date command will be adjusted accordingly.


The following variables affect networking behavior:

Variable Default Constraints Description
ethaddr as set by mfg. ethernet addr This variable is used to specify the hardware Ethernet address on platforms which does not provide a way to store this value with the actual HW function. It should not be used for any other purpose. It is not used or available on platforms not having need for it. See the section on Ethernet specifics for further information.
ifconfig <none> <interface configuration string> This variable is used to automatically configure any network interfaces during bootup. The variable is set to ';' separated strings, one for each interface, that should be configured. The first interface set up will get the default route. For information about how to set up the string see the ifaddr command.
localdomain <none> This variable should be set to the name of the local domain when using a nameserver.
nameserver <none> This variable is set to a whitespace separated list of nameserver ip addresses to enable the nameserver lookup function.

Booting & dumping

The following variables affect booting:

Variable Default Constraints Description
autoboot <none> <max string> This is the command which will be executed to autoboot a system. If this variable is set PMON will execute it after the number of seconds specified in bootdelay have elapsed. If the variable is not set, PMON2000 will enter the command shell.
bootdelay <none> <integer> Specifies the delay in seconds before autoboot is executed.
bootfile <none> <pathname> If no filename is given to the boot command the value set to this variable, if set, will be used as the filename.
dlproto EtxAck [none EtxAck XonXoff] Specifies the download protocol used when loading via serial port.
hostport tty0 <loadable port> This variable will be used to select the port to be used when downloading is done using the oload command.
dlecho off [off on lfeed] This variable controls whether the target board echoes on downloads. An entire line can be echoed, a single linefeed character can be echoed, or there can be no echo at all. See the load command and the section on flow control.
ulcr cr [cr lf crlf] This variable defines whether there is a carriage return or both a carriage return and a linefeed character at the end of the line during dumps. See the dump command.
uleof % <max string> This variable specifies a string that is sent to the host after a dump to the target has completed. See the dump command.


The following variables affect debugging:

Variable Default Constraints Description
brkcmd l -r @cpc 1 <max string> This variable specifies a sequence of commands that are executed when a breakpoint halts program execution. See the b command.
regstyle sw [hw sw] This variable defines whether hardware or software names are displayed in the l command. See the l command.
showsym yes [no yes] Show or don't show symbols when doing trace and disassembly.
validpc _ftext etext <low high> This variable specifies the range of valid PC values during program tracing. See the trace command.
regsize 32 [32 64] Register display size. Only valid on architectures with 64 bit registers.

Misc. variables

The following variables are not actually used by PMON itself but are set up accordingly and passed to a downloaded program in the environment when started:

Variable Description
busclock Normally set to the clock speed of the processors external bus.
cpuclock Normally set to the internal pipeline clock speed of the processor.
memsize Set to the number of megabytes of memory.
systype Set to a unique name that identifies the target platform model.
l3cache This variable will be set to the size of the Level3 cache on systems with this feature. On other platforms it is not available.
vxWorks This string variable maintained by PMON2000 is used by vxWorks. It is stored in non volatile memory in a location known by the vxWorks BSP for the target platform. The string is also copied to ram in the same way as the vxWorks boot do it. See Wind River documentation for details.
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