+++ /dev/null
-<!-- Copyright (C) 2003 Red Hat, Inc. -->
-<!-- This material may be distributed only subject to the terms -->
-<!-- and conditions set forth in the Open Publication License, v1.0 -->
-<!-- or later (the latest version is presently available at -->
-<!-- http://www.opencontent.org/openpub/). -->
-<!-- Distribution of the work or derivative of the work in any -->
-<!-- standard (paper) book form is prohibited unless prior -->
-<!-- permission is obtained from the copyright holder. -->
-<HTML
-><HEAD
-><TITLE
->legal_values</TITLE
-><meta name="MSSmartTagsPreventParsing" content="TRUE">
-<META
-NAME="GENERATOR"
-CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
-"><LINK
-REL="HOME"
-TITLE="The eCos Component Writer's Guide"
-HREF="cdl-guide.html"><LINK
-REL="UP"
-TITLE="CDL Language Specification"
-HREF="reference.html"><LINK
-REL="PREVIOUS"
-TITLE="include_files"
-HREF="ref.include-files.html"><LINK
-REL="NEXT"
-TITLE="library"
-HREF="ref.library.html"></HEAD
-><BODY
-CLASS="REFENTRY"
-BGCOLOR="#FFFFFF"
-TEXT="#000000"
-LINK="#0000FF"
-VLINK="#840084"
-ALINK="#0000FF"
-><DIV
-CLASS="NAVHEADER"
-><TABLE
-SUMMARY="Header navigation table"
-WIDTH="100%"
-BORDER="0"
-CELLPADDING="0"
-CELLSPACING="0"
-><TR
-><TH
-COLSPAN="3"
-ALIGN="center"
->The <SPAN
-CLASS="APPLICATION"
->eCos</SPAN
-> Component Writer's Guide</TH
-></TR
-><TR
-><TD
-WIDTH="10%"
-ALIGN="left"
-VALIGN="bottom"
-><A
-HREF="ref.include-files.html"
-ACCESSKEY="P"
->Prev</A
-></TD
-><TD
-WIDTH="80%"
-ALIGN="center"
-VALIGN="bottom"
-></TD
-><TD
-WIDTH="10%"
-ALIGN="right"
-VALIGN="bottom"
-><A
-HREF="ref.library.html"
-ACCESSKEY="N"
->Next</A
-></TD
-></TR
-></TABLE
-><HR
-ALIGN="LEFT"
-WIDTH="100%"></DIV
-><H1
-><A
-NAME="REF.LEGAL-VALUES"><SPAN
-CLASS="PROPERTY"
->legal_values</SPAN
-></H1
-><DIV
-CLASS="REFNAMEDIV"
-><A
-NAME="AEN4615"
-></A
-><H2
->Name</H2
->Property <SPAN
-CLASS="PROPERTY"
->legal_values</SPAN
-> -- Impose constraints on the possible values for an option.</DIV
-><DIV
-CLASS="REFSYNOPSISDIV"
-><A
-NAME="AEN4619"><H2
->Synopsis</H2
-><TABLE
-BORDER="5"
-BGCOLOR="#E0E0F0"
-WIDTH="70%"
-><TR
-><TD
-><PRE
-CLASS="SYNOPSIS"
->cdl_option <name> {
- legal_values <list expression>
- …
-}</PRE
-></TD
-></TR
-></TABLE
-></DIV
-><DIV
-CLASS="REFSECT1"
-><A
-NAME="AEN4621"
-></A
-><H2
->Description</H2
-><P
->Options with the <TT
-CLASS="LITERAL"
->data</TT
-> or
-<TT
-CLASS="LITERAL"
->booldata</TT
-> flavors can have an arbitrary sequence of
-characters as their data. In nearly all cases some restrictions have
-to be imposed, for example the data should correspond to a number
-within a certain range, or it should be one of a small number of
-constants. The <SPAN
-CLASS="PROPERTY"
->legal_values</SPAN
-> property can be used to impose such
-constraints. The arguments to the property should be a <SPAN
-CLASS="APPLICATION"
->CDL</SPAN
-> list
-expression, see <A
-HREF="language.values.html#LANGUAGE.LIST-EXPRESSION"
->the Section called <I
->List Expressions</I
-> in Chapter 3</A
-> for the
-syntactic details. Common examples include:</P
-><TABLE
-BORDER="5"
-BGCOLOR="#E0E0F0"
-WIDTH="70%"
-><TR
-><TD
-><PRE
-CLASS="PROGRAMLISTING"
-> legal_values 0 to 0x7fff
- legal_values 9600 19200 38400
- legal_values { "RAM" "ROM" }</PRE
-></TD
-></TR
-></TABLE
-><P
->The <SPAN
-CLASS="PROPERTY"
->legal_values</SPAN
-> property can only be used for options with the
-<TT
-CLASS="LITERAL"
->data</TT
-> or <TT
-CLASS="LITERAL"
->booldata</TT
-> flavors, since
-it makes little sense to further constrain the legal values of a
-boolean option. An option can have at most one <SPAN
-CLASS="PROPERTY"
->legal_values</SPAN
->
-property.</P
-><DIV
-CLASS="TIP"
-><BLOCKQUOTE
-CLASS="TIP"
-><P
-><B
->Tip: </B
->If the first entry in a <SPAN
-CLASS="PROPERTY"
->legal_values</SPAN
-> list expression is a negative
-number, for example
-<TT
-CLASS="LITERAL"
->legal_values -1 to 1</TT
-> then this can
-be misinterpreted as an option instead of as part of the expression.
-Currently the <SPAN
-CLASS="PROPERTY"
->legal_values</SPAN
-> property does not take any options, but
-this may change in future. Option processing halts at the sequence
-<TT
-CLASS="LITERAL"
->--</TT
->, so the desired range can be expressed safely
-using <TT
-CLASS="LITERAL"
->legal_values -- -1 to 1</TT
-></P
-></BLOCKQUOTE
-></DIV
-><DIV
-CLASS="NOTE"
-><BLOCKQUOTE
-CLASS="NOTE"
-><P
-><B
->Note: </B
->Architectural HAL packages should provide constants which can be used
-in <SPAN
-CLASS="PROPERTY"
->legal_values</SPAN
-> list expressions. For example it should be possible
-to specify a numeric range such as
-<TT
-CLASS="LITERAL"
->0 to CYGARC_MAXINT</TT
->, rather than
-hard-wiring numbers such as <TT
-CLASS="LITERAL"
->0x7fffffff</TT
-> which may
-not be valid on all targets. Current HAL packages do not define such
-constants. </P
-></BLOCKQUOTE
-></DIV
-><DIV
-CLASS="NOTE"
-><BLOCKQUOTE
-CLASS="NOTE"
-><P
-><B
->Note: </B
->The <SPAN
-CLASS="PROPERTY"
->legal_values</SPAN
-> property is restricted mainly to numerical ranges
-and simple enumerations, and cannot cope with more complicated data
-items. Future versions of the configuration system will provide
-additional data validation facilities, for example a
-<TT
-CLASS="LITERAL"
->check_proc</TT
-> property which specifies a Tcl script
-that can be used to perform the validation.</P
-></BLOCKQUOTE
-></DIV
-></DIV
-><DIV
-CLASS="REFSECT1"
-><A
-NAME="AEN4651"
-></A
-><H2
->Example</H2
-><TABLE
-BORDER="5"
-BGCOLOR="#E0E0F0"
-WIDTH="70%"
-><TR
-><TD
-><PRE
-CLASS="PROGRAMLISTING"
->cdl_option CYGNUM_LIBC_TIME_STD_DEFAULT_OFFSET {
- display "Default Standard Time offset"
- flavor data
- legal_values -- -90000 to 90000
- default_value -- 0
- description "
- This option controls the offset from UTC in
- seconds when in local Standard Time. This
- value can be positive or negative. It
- can also be set at run time using the
- cyg_libc_time_setzoneoffsets() function."
-}</PRE
-></TD
-></TR
-></TABLE
-></DIV
-><DIV
-CLASS="REFSECT1"
-><A
-NAME="AEN4654"
-></A
-><H2
->See Also</H2
-><P
->Properties <A
-HREF="ref.calculated.html"
-><SPAN
-CLASS="PROPERTY"
->calculated</SPAN
-></A
->,
-<A
-HREF="ref.default-value.html"
-><SPAN
-CLASS="PROPERTY"
->default_value</SPAN
-></A
->, and
-<A
-HREF="ref.flavor.html"
-><SPAN
-CLASS="PROPERTY"
->flavor</SPAN
-></A
->.</P
-></DIV
-><DIV
-CLASS="NAVFOOTER"
-><HR
-ALIGN="LEFT"
-WIDTH="100%"><TABLE
-SUMMARY="Footer navigation table"
-WIDTH="100%"
-BORDER="0"
-CELLPADDING="0"
-CELLSPACING="0"
-><TR
-><TD
-WIDTH="33%"
-ALIGN="left"
-VALIGN="top"
-><A
-HREF="ref.include-files.html"
-ACCESSKEY="P"
->Prev</A
-></TD
-><TD
-WIDTH="34%"
-ALIGN="center"
-VALIGN="top"
-><A
-HREF="cdl-guide.html"
-ACCESSKEY="H"
->Home</A
-></TD
-><TD
-WIDTH="33%"
-ALIGN="right"
-VALIGN="top"
-><A
-HREF="ref.library.html"
-ACCESSKEY="N"
->Next</A
-></TD
-></TR
-><TR
-><TD
-WIDTH="33%"
-ALIGN="left"
-VALIGN="top"
-><SPAN
-CLASS="PROPERTY"
->include_files</SPAN
-></TD
-><TD
-WIDTH="34%"
-ALIGN="center"
-VALIGN="top"
-><A
-HREF="reference.html"
-ACCESSKEY="U"
->Up</A
-></TD
-><TD
-WIDTH="33%"
-ALIGN="right"
-VALIGN="top"
-><SPAN
-CLASS="PROPERTY"
->library</SPAN
-></TD
-></TR
-></TABLE
-></DIV
-></BODY
-></HTML
->
\ No newline at end of file
projects / karo-tx-redboot.git / blobdiff