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<part id="redboot"><beginpage>
<title>RedBoot&trade; User's Guide</title>
<toc id="Getting-Started-with-Redboot2"></toc>
<chapter id="Getting-Started-with-RedBoot">
<title>Getting Started with RedBoot</title>
<para><indexterm><primary>Red Boot</primary><secondary>getting started</secondary>
</indexterm>RedBoot&trade; is an acronym for "Red Hat Embedded Debug and Bootstrap",
and is the standard embedded system debug/bootstrap environment from Red Hat,
replacing the previous generation of debug firmware: <indexterm><primary>CygMon</primary>
</indexterm>CygMon and <indexterm><primary>GDB stubs</primary></indexterm>GDB
stubs. It provides a complete bootstrap environment for a range of embedded
operating systems, such as embedded Linux&trade; and eCos&trade;, and includes facilities
such as network downloading and debugging. It also provides a simple flash
file system for boot images.</para>
<para>RedBoot provides a wide set of tools for downloading and executing programs
on embedded target systems, as well as tools for manipulating the target system's
environment. It can be used for both product development (debug support) and
for end product deployment (flash and network booting).</para>
<para>Here are some highlights of <indexterm><primary>RedBoot's capabilities
</primary></indexterm>RedBoot&rsquo;s capabilities:  </para>
<itemizedlist>
<listitem><para>Boot scripting support</para>
</listitem>
<listitem><para>Simple command line interface for RedBoot configuration and
management, accessible via serial (terminal) or Ethernet (telnet) </para>
</listitem>
<listitem><para>Integrated GDB stubs for connection to a host-based debugger
via serial or ethernet. (Ethernet connectivity is limited to local network
only)</para>
</listitem>
<listitem><para>Attribute Configuration - user control of aspects such as
system time and date (if applicable), default Flash image to boot from, default
failsafe image, static IP address, etc.</para>
</listitem>
<listitem><para>Configurable and extensible, specifically adapted to the target
environment </para>
</listitem>
<listitem><para>Network bootstrap support including setup and download, via
BOOTP, DHCP and TFTP</para>
</listitem>
<listitem><para>X/YModem support for image download via serial</para>
</listitem>
<listitem><para>Power On Self Test</para>
</listitem>
</itemizedlist>
<para>Although RedBoot is derived from eCos, it may be used as a generalized
system debug and bootstrap control software for any embedded system and any
operating system. For example, with appropriate additions, RedBoot could replace
the commonly used BIOS of PC (and certain other) architectures. Red Hat is
currently installing RedBoot on all embedded platforms as a standard practice,
and RedBoot is now generally included as part of all Red Hat Embedded Linux
and eCos ports. Users who specifically wish to use RedBoot with the eCos operating
system should refer to the <emphasis>Getting Started with eCos</emphasis>
document, which provides information about the portability and extendability
of RedBoot in an eCos environment.</para>
<sect1 id="redboot-on-the-web">
<title>More information about RedBoot on the web</title>
<para>The <ulink url="http://sources.redhat.com/redboot/">RedBoot Net
Distribution web site</ulink> contains downloadable sources and documentation
for all publically released targets, including the latest features and updates.
</para>
</sect1>
<sect1 id="installing-redboot">
<title>Installing RedBoot</title>
<para><indexterm><primary>installing RedBoot</primary><secondary>general procedures
</secondary></indexterm><indexterm><primary>RedBoot installation</primary>
<secondary>general procedures</secondary></indexterm>To install the RedBoot
package, follow the procedures detailed in the accompanying README. </para>
<para>Although there are other possible configurations, RedBoot is usually
run from the target platform&rsquo;s flash boot sector or boot ROM, and is
designed to run when your system is initially powered on. The method used
to install the RedBoot image into non-volatile storage varies from platform
to platform. In general, it requires that the image be programmed into flash
in situ or programmed into the flash or ROM using a device programmer. In
some cases this will be done at manufacturing time; the platform being delivered
with RedBoot already in place. In other cases, you will have to program RedBoot
into the appropriate device(s) yourself. Installing to flash in situ may require
special cabling or interface devices and software provided by the board manufacturer.
The details of this installation process for a given platform will be found
in Installation and Testing. Once installed, user-specific configuration options
may be applied, using the <command>fconfig</command> command,
providing that persistent data storage in flash is present in the relevant
RedBoot version. See <xref linkend="Configuring-the-RedBoot-Environment">
for details.</para>
</sect1>
<sect1 id="user-interface">
<title>User Interface</title>
<para><indexterm><primary>user interface</primary></indexterm><indexterm>
<primary>ui</primary></indexterm><indexterm><primary>cli</primary></indexterm>RedBoot
provides a command line user interface (CLI). At the minimum, this interface
is normally available on a serial port on the platform. If more than one serial
interface is available, RedBoot is normally configured to try to use any one
of the ports for the CLI. Once command input has been received on one port,
that port is used exclusively until the board is reset or the channel
is manually changed by the
user. If the platform has networking
capabilities, the RedBoot CLI is also accessible using the <computeroutput>
telnet</computeroutput> access protocol. By default, RedBoot runs <computeroutput><indexterm>
<primary>telnet</primary></indexterm>telnet</computeroutput> on port TCP/9000,
but this is configurable and/or settable by the user. </para>
<para>RedBoot also contains a set of <indexterm><primary>GDB stubs</primary>
</indexterm>GDB "stubs", consisting of code which supports the GDB remote
protocol. GDB stub mode is automatically invoked when the '$' character appears
anywhere on a command line unless escaped using the '\' character. 
The platform will remain in GDB
stub mode until explicitly disconnected (via the GDB protocol). The GDB stub
mode is available regardless of the connection method; either serial or network.
Note that if a GDB connection is made via the network, then special care must
be taken to preserve that connection when running user code. eCos contains
special network sharing code to allow for this situation, and can be used
as a model if this methodology is required in other OS environments.</para>
</sect1>

<sect1 id="RedBoot-Editing-Commands">
<title>RedBoot Editing Commands</title>
<para><indexterm><primary>RedBoot</primary><secondary>editing commands</secondary>
</indexterm><indexterm><primary>editing commands</primary></indexterm><indexterm>
<primary>commands</primary><secondary>editing</secondary></indexterm>RedBoot
uses the following line editing commands. 
<note><title>NOTE</title>
<para>
In this description, <guibutton>^A</guibutton> means the character formed
by typing the letter &ldquo;A&rdquo; while holding down the control key.
</para></note>
<itemizedlist>
<listitem><para><guibutton>Delete</guibutton> (0x7F) or 
<guibutton>Backspace</guibutton> (0x08) 
erases the character to the left of the cursor.
</para></listitem>
<listitem><para>
<guibutton>^A</guibutton>
moves the cursor (insertion point) to the beginning of the line.
</para></listitem>
<listitem><para>
<guibutton>^K</guibutton>
erases all characters on the line from the cursor to the end.
</para></listitem>
<listitem><para>
<guibutton>^E</guibutton>
positions the cursor to the end of the line.
</para></listitem>
<listitem><para>
<guibutton>^D</guibutton>
erases the character under the cursor.
</para></listitem>
<listitem><para>
<guibutton>^F</guibutton>
moves the cursor one character to the right.
</para></listitem>
<listitem><para>
<guibutton>^B</guibutton>
moves the cursor one character to the left.
</para></listitem>
<listitem><para>
<guibutton>^P</guibutton>
replaces the current line by a previous line from the history buffer.  
A small number of lines
can be kept as history.  Using ^P (and ^N), the current line can be replaced
by any one of the previously typed lines.
</para></listitem>
<listitem><para>
<guibutton>^N</guibutton>
replaces the current line by the next line from the history buffer.  
</para></listitem>
</itemizedlist></para>
<para>In the case of the <command>fconfig</command>
command, additional editing commands are possible. 
As data are entered for this command, the current/previous value
will be displayed and the cursor placed at the end of that data.
The user may use the editing keys (above) to move around in the data
to modify it as appropriate.
Additionally, when certain
characters are entered at the end of the current value, 
i.e. entered separately, certain behavior is elicited.</para>
<para><itemizedlist>
<listitem>
<para>^ (caret) switch to editing the previous item in the 
<command>fconfig</command> list. If fconfig edits item A, followed by item B,
pressing ^ when changing item B, allows you to change item A. This is similar
to the up arrow.
Note: ^P and ^N do not have the same meaning while editing 
<command>fconfig</command> data and should not be used.
</para>
</listitem>
<listitem><para>. (period) stop editing any further items. This does not change
the current item.</para>
</listitem>
<listitem><para><guibutton>Return</guibutton> leaves the value
for this item unchanged. Currently it is not possible to step through the
value for the start-up script; it must always be retyped.</para>
</listitem>
</itemizedlist></para>
</sect1>

<sect1 id="startup-mode">
<title>RedBoot Startup Mode</title>
<para>
  <indexterm><primary>RedBoot</primary><secondary>mode</secondary></indexterm>
  <indexterm><primary>RedBoot</primary><secondary>startup mode</secondary></indexterm>
</para>