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D.12 Memory Map Format

To be able to write into flash memory, gdb needs to obtain a memory map from the target. This section describes the format of the memory map.

The memory map is obtained using the `qXfer:memory-map:read' (see qXfer memory map read) packet and is an XML document that lists memory regions. The top-level structure of the document is shown below:

     <?xml version="1.0"?>
     <!DOCTYPE memory-map
               PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN"
                      "http://sourceware.org/gdb/gdb-memory-map.dtd">
     <memory-map>
         region...
     </memory-map>

Each region can be either:

Regions must not overlap. gdb assumes that areas of memory not covered by the memory map are RAM, and uses the ordinary `M' and `X' packets to write to addresses in such ranges.

The formal DTD for memory map format is given below:

     <!-- ................................................... -->
     <!-- Memory Map XML DTD ................................ -->
     <!-- File: memory-map.dtd .............................. -->
     <!-- .................................... .............. -->
     <!-- memory-map.dtd -->
     <!-- memory-map: Root element with versioning -->
     <!ELEMENT memory-map (memory | property)>
     <!ATTLIST memory-map    version CDATA   #FIXED  "1.0.0">
     <!ELEMENT memory (property)>
     <!-- memory: Specifies a memory region,
                  and its type, or device. -->
     <!ATTLIST memory        type    CDATA   #REQUIRED
                             start   CDATA   #REQUIRED
                             length  CDATA   #REQUIRED
                             device  CDATA   #IMPLIED>
     <!-- property: Generic attribute tag -->
     <!ELEMENT property (#PCDATA | property)*>
     <!ATTLIST property      name    CDATA   #REQUIRED>