Board File Syntax

The board-file can be a user-written XML file to describe a non-standard board. The Sourcery G++ Debug Sprite searches for board files in the arm-none-eabi/lib/boards directory in the installation. Refer to the files in that directory for examples.

The file's DTD is:

<!-- Board description files

     Copyright 2007, 2008 CodeSourcery.  All rights reserved.

     This file is licensed only for use with Sourcery G++.  No other use is
     permitted.
     -->

<!ELEMENT board
	(properties?, feature?, initialize?, memory-map?)>

<!ELEMENT properties
	(description?, property*)>

<!ELEMENT initialize
	(write-register | write-memory | delay
	 | wait-until-memory-equal | wait-until-memory-not-equal)* >
<!ELEMENT write-register EMPTY>
<!ATTLIST write-register
		        address CDATA   #REQUIRED
                        value   CDATA   #REQUIRED
                        bits    CDATA   #IMPLIED>
<!ELEMENT write-memory EMPTY>
<!ATTLIST write-memory
		        address CDATA   #REQUIRED
                        value   CDATA   #REQUIRED
                        bits    CDATA   #IMPLIED>
<!ELEMENT delay EMPTY>
<!ATTLIST delay
		        time CDATA   #REQUIRED>
<!ELEMENT wait-until-memory-equal EMPTY>
<!ATTLIST wait-until-memory-equal
		        address CDATA   #REQUIRED
                        value   CDATA   #REQUIRED
                        timeout CDATA   #IMPLIED
                        bits    CDATA   #IMPLIED>
<!ELEMENT wait-until-memory-not-equal EMPTY>
<!ATTLIST wait-until-memory-not-equal
		        address CDATA   #REQUIRED
                        value   CDATA   #REQUIRED
                        timeout CDATA   #IMPLIED
                        bits    CDATA   #IMPLIED>

<!ELEMENT memory-map (memory-device)*>
<!ELEMENT memory-device (property*,  description?)>
<!ATTLIST memory-device
                        address CDATA   #REQUIRED
		        size    CDATA   #REQUIRED
		        type    CDATA   #REQUIRED
                        device  CDATA   #IMPLIED>

<!ELEMENT description (#PCDATA)>
<!ELEMENT property (#PCDATA)>
<!ATTLIST property name CDATA #REQUIRED>

<!ENTITY % gdbtarget SYSTEM "gdb-target.dtd">
%gdbtarget;

All values can be provided in decimal, hex (with a 0x prefix) or octal (with a 0 prefix). Addresses and memory sizes can use a K, KB, M, MB, G or GB suffix to denote a unit of memory. Times must use a ms or us suffix.

The following elements are available:

<board>

This top level element encapsulates the entire description of the board. It can contain <properties>, <features>, <initialize> and <memory-map> elements.

<properties>

The <properties> element specifies specific properties of the target system. This element can occur at most once. It can contain a <description> element. It can also contain the following <property> elements:

<banked-regs>

The <banked-regs> element specifies that the CPU of the target board has banked registers for different processor modes (supervisor, IRQ, etc.).

<has-vfp>

The <has-vfp> element specifies that the CPU of the target board has VFP registers.

<system-v6-m>

The <system-v6-m> element specifies that the CPU of the target board has ARMv6-M architecture system registers.

<system-v7-m>

The <system-v7-m> element specifies that the CPU of the target board has ARMv7-M architecture system registers.

<initialize>

The <initialize> element allows board devices to be initialized before any attempt is made to download a program to it. It can contain <write-register>, <write-memory> and <delay> elements.

<feature>

This element is used to inform GDB about additional registers and peripherals available on the board. It is passed directly to GDB; see the GDB manual for further details.

<memory-map>

This element describes the memory map of the target board. It is used by GDB to determine where software breakpoints may be used and when flash programming sequences must be used. This element can occur at most once. It can contain <memory-device> elements.

<memory-device>

This element specifies a region of memory. It has four attributes: address, size, type and device. The address and size attributes specify the location of the memory device. The type attribute specifies that device as ram, rom or flash. The device attribute is required for flash regions; it specifies the flash device type. The <memory-device> element can contain a <description> element.

<write-register>

This element writes a value to a control register. It has three attributes: address, value and bits. The bits attribute is optional and defaults to 32.

<write-memory>

This element writes a value to a memory location. It has three attributes: address, value and bits. The bits attribute is optional and defaults to 32. Bit widths of 8, 16 and 32 bits are supported. The address written to must be naturally aligned for the size of the write being done.

<delay>

This element introduces a delay. It has one attribute, time, which specifies the number of milliseconds, or microseconds to delay by.

<description>

This element encapsulates a human-readable description of its enclosing element.

<property>

The <property> element allows additional name/value pairs to be specified. The property name is specified in a name attribute. The property value is the body of the <property> element.