1.5 Conventions Used in this Document

This document uses typographic and illustrative conventions described below.

1.5.1 Data Structure Descriptions

Intel(R) processors based on 32 bit Intel(R) architecture (IA 32) are "little endian" machines. This distinction means that the low-order byte of a multi byte data item in memory is at the lowest address, while the high-order byte is at the highest address.

Processors of the Intel(R) Itanium(R) processor family may be configured for both "little endian" and "big endian" operation. All implementations designed to conform to this specification will use "little endian" operation.

In some memory layout descriptions, certain fields are marked reserved. Software must initialize such fields to zero and ignore them when read. On an update operation, software must preserve any reserved field.

The data structures described in this document generally have the following format:

STRUCTURE_NAME

The formal name of the data structure.

Summary

A brief description of the data structure.

Prototype

An EBNF-type declaration for the data structure..

Example

Sample data structure using the prototype.

Description

A description of the functionality provided by the data structure, including any limitations and caveats of which the caller must be aware.

The type declarations and constants that are used only by this data structure.

1.5.2 Pseudo-Code Conventions

Pseudo code is presented to describe algorithms in a more concise form. None of the algorithms in this document are intended to be compiled directly. The code is presented at a level corresponding to the surrounding text.

In describing variables, a list is an unordered collection of homogeneous objects. A queue is an ordered list of homogeneous objects. Unless otherwise noted, the ordering is assumed to be FIFO.

Pseudo code is presented in a C-like format, using C conventions where appropriate. The coding style, particularly the indentation style, is used for readability and does not necessarily comply with an implementation of the Extensible Firmware Specification.

1.5.3 Typographic Conventions

This document uses the typographic and illustrative conventions described below:

Typographic Convention Typographic convention description
Plain text The normal text typeface is used for the vast majority of the descriptive text in a specification.
Plain text (blue) Any plain text that is underlined and in blue indicates an active link to the crossreference. Click on the word to follow the hyperlink.
Bold In text, a Bold typeface identifies a processor register name. In other instances, a Bold typeface can be used as a running head within a paragraph.
Italic In text, an Italic typeface can be used as emphasis to introduce a new term or to indicate a manual or specification name.
BOLD Monospace Computer code, example code segments, and all prototype code segments use a BOLD Monospace typeface with a dark red color. These code listings normally appear in one or more separate paragraphs, though words or segments can also be embedded in a normal text paragraph.
Bold Monospace Words in a Bold Monospace typeface that is underlined and in blue indicate an active hyper link to the code definition for that function or type definition. Click on the word to follow the hyper link.
$(VAR) This symbol VAR defined by the utility or input files.
Italic Bold In code or in text, words in Italic Bold indicate placeholder names for variable information that must be supplied (i.e., arguments).

Note: Due to management and file size considerations, only the first occurrence of the reference on each page is an active link. Subsequent references on the same page will not be actively linked to the definition and will use the standard, non-underlined BOLD Monospace typeface. Find the first instance of the name (in the underlined Bold Monospace typeface) on the page and click on the word to jump to the function or type definition.

The following typographic conventions are used in this document to illustrate the Extended Backus-Naur Form.

Typographic Convention Typographic convention description
[item] Square brackets denote the enclosed item is optional.
{item} Curly braces denote a choice or selection item, only one of which may occur on a given line.
<item> Angle brackets denote a name for an item.
(range-range) Parenthesis with characters and dash characters denote ranges of values, for example, (a-zA-Z0-9) indicates a single alphanumeric character, while (0-9) indicates a single digit.
"item" Characters within quotation marks are the exact content of an item, as they must appear in the output text file.
? The question mark denotes zero or one occurrences of an item.
* The star character denotes zero or more occurrences of an item.
+ The plus character denotes one or more occurrences of an item.
item{n} A superscript number, n, is the number occurrences of the item that must be used. Example: (0-9)8 indicates that there must be exactly eight digits, so 01234567 is valid, while 1234567 is not valid.
item{n,} A superscript number, n, within curly braces followed by a comma "," indicates the minimum number of occurrences of the item, with no maximum number of occurrences.
item{,n} A superscript number, n, within curly brackets, preceded by a comma ","indicates a maximum number of occurrences of the item.
item{n,m} A super script number, n, followed by a comma "," and a number, m, indicates that the number of occurrences can be from n to m occurrences of the item, inclusive.