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.