Package ghidra.program.model.address

Class SegmentedAddressSpace

  • All Implemented Interfaces:
    AddressSpace, java.lang.Comparable<AddressSpace>
    Direct Known Subclasses:
    ProtectedAddressSpace
    public class SegmentedAddressSpace
extends GenericAddressSpace
    Address Space for dealing with (intel) segmented address spaces. It understands the mapping between the segmented encoding (seg:offset) and the flat address encoding necessary to produce an Address object that can be used by other analyses. This mapping is inherent in protected methods: - getDefaultOffsetFromFlat - getDefaultSegmentFromFlat - getFlatOffset - getOffsetFromFlat - getAddressInSegment These 5 methods can be overridden to get a different mapping. This base class is set up to map as for x86 16-bit real-mode.

    • Field Detail

      • name

        protected java.lang.String name

      • size

        protected int size

      • unitSize

        protected int unitSize

      • type

        protected int type

      • spaceSize

        protected long spaceSize

      • signed

        protected boolean signed

      • minOffset

        protected long minOffset

      • maxOffset

        protected long maxOffset

      • minAddress

        protected Address minAddress

      • maxAddress

        protected Address maxAddress

      • spaceID

        protected int spaceID

    • Constructor Detail

      • SegmentedAddressSpace

        protected SegmentedAddressSpace​(java.lang.String name,
                                int size,
                                int unique)
        Constructor for larger size address spaces (than the real-mode space)
        Parameters:
        name - is the name of the space
        size - is the number of bits in a (flat) address
        unique - is the unique id for the space

      • SegmentedAddressSpace

        public SegmentedAddressSpace​(java.lang.String name,
                             int unique)
        Constructs a new Segmented AddressSpace for x86 real-mode, with 21-bit addresses.
        Parameters:
        name - is the name of the space
        unique - is the unique id for the space.

    • Method Detail

      • getFlatOffset

        protected long getFlatOffset​(int segment,
                             long offset)
        Given a 16-bit segment and an offset, produce the flat address offset
        Parameters:
        segment - is the segment value
        offset - is the 16-bit offset into the segment
        Returns:
        the encoded flat offset

      • getDefaultSegmentFromFlat

        protected int getDefaultSegmentFromFlat​(long flat)
        Given a flat address offset, extract the default 16-bit segment portion
        Parameters:
        flat - is the flat offset
        Returns:
        the segment value

      • getDefaultOffsetFromFlat

        protected long getDefaultOffsetFromFlat​(long flat)
        Given a flat address offset, extract the offset portion assuming the default segment.
        Parameters:
        flat - is the flat offset
        Returns:
        the offset value

      • getOffsetFromFlat

        protected long getOffsetFromFlat​(long flat,
                                 int segment)
        Given a flat address offset, extract a segment offset assuming a specific segment value.
        Parameters:
        flat - is the flat offset
        segment - is the specific segment value
        Returns:
        the segment offset

      • getAddressInSegment

        protected SegmentedAddress getAddressInSegment​(long flat,
                                               int preferredSegment)
        Given a flat address offset and a preferred segment, try to create an address that maps to the offset and is in the segment. For architectures like x86 real-mode, multiple address encodings can map to the same flat address offset. This method tries to select between the different encodings. If the flat offset cannot be encoded with the preferred segment, null is returned.
        Parameters:
        flat - is the flat offset
        preferredSegment - is the 16-bit preferred segment value
        Returns:
        the segment encoded address or null

      • getAddress

        public Address getAddress​(java.lang.String addrString,
                          boolean caseSensitive)
                   throws AddressFormatException
        Description copied from interface: AddressSpace
        Parses the String into an address.
        Specified by:
        getAddress in interface AddressSpace
        Parameters:
        addrString - the string to parse as an address.
        caseSensitive - specifies if addressSpace names must match case.
        Returns:
        an address if the string parsed successfully or null if the AddressSpace specified in the addrString is not this space.
        Throws:
        AddressFormatException - if the string cannot be parsed or the parsed offset is larger than the size for this space.

      • getUncheckedAddress

        protected SegmentedAddress getUncheckedAddress​(long byteOffset)
        Instantiates an address within this space. No offset validation should be performed.
        Overrides:
        getUncheckedAddress in class GenericAddressSpace
        See Also:
        AbstractAddressSpace.getUncheckedAddress(long)

      • getAddress

        public SegmentedAddress getAddress​(int segment,
                                   int segmentOffset)
        Generates a segmented address with the given segment, offset, and overlay id.
        Parameters:
        segment - the segment
        segmentOffset - the offset in the segment
        Returns:
        SegmentedAddress the newly created segmented address.

      • getNextOpenSegment

        public int getNextOpenSegment​(Address addr)
        Get the segment index for the first segment whose start address comes after the given address
        Parameters:
        addr - is the given address
        Returns:
        the segment index

      • getSize

        public int getSize()
        Description copied from interface: AddressSpace
        Returns the number of bits that are used to form the address. Thus the maximum offset for this address space will be 2^size-1.
        Specified by:
        getSize in interface AddressSpace
        See Also:
        AddressSpace.getSize()

      • getAddressableUnitSize

        public int getAddressableUnitSize()
        Description copied from interface: AddressSpace
        Returns the number of data bytes which correspond to each addressable location within this space (i.e., word-size in bytes). NOTE: When transforming a byte-offset to an addressable word offset the method AddressSpace.getAddressableWordOffset(long) should be used instead of simple division. When transforming an addressable word-offset to a byte-offset simple multiplication may be used. Neither of these transformations perform address space bounds checking. 
           byteOffset = wordOffset * addressUnitSize
   wordOffset = getAddressableWordOffset(byteOffset)
        Specified by:
        getAddressableUnitSize in interface AddressSpace
        See Also:
        AddressSpace.getAddressableUnitSize()

      • getAddressableWordOffset

        public long getAddressableWordOffset​(long byteOffset)
        Description copied from interface: AddressSpace
        Get the addressable memory word offset which corresponds to the specified memory byte offset. This method handles some of the issues of unsigned math when stuck using Java's signed long primitives. No space bounds checking is performed.
        Specified by:
        getAddressableWordOffset in interface AddressSpace
        Parameters:
        byteOffset - memory byte offset
        Returns:
        addressable memory word offset

      • getUnique

        public int getUnique()
        Returns the unique id value for this space.
        Specified by:
        getUnique in interface AddressSpace

      • getAddress

        public Address getAddress​(long offset,
                          boolean isAddressableWordOffset)
                   throws AddressOutOfBoundsException
        Description copied from interface: AddressSpace
        Returns a new address in this space with the given offset. NOTE: for those spaces with an addressable unit size other than 1, the address returned may not correspond to an addressable unit/word boundary if a byte-offset is specified.
        Specified by:
        getAddress in interface AddressSpace
        Parameters:
        offset - the offset for the new address.
        isAddressableWordOffset - if true the specified offset is an addressable unit/word offset, otherwise offset is a byte offset. See AddressSpace.getAddressableUnitSize() to understand the distinction (i.e., wordOffset = byteOffset * addressableUnitSize).
        Returns:
        address with given offset
        Throws:
        AddressOutOfBoundsException - if the offset is less than 0 or greater than the max offset allowed for this space.

      • getTruncatedAddress

        public Address getTruncatedAddress​(long offset,
                                   boolean isAddressableWordOffset)
        Description copied from interface: AddressSpace
        Returns a new address in this space with the given offset. The specified offset will be truncated within the space and will not throw an exception. NOTE: for those spaces with an addressable unit size other than 1, the address returned may not correspond to a word boundary (addressable unit) if a byte-offset is specified.
        Specified by:
        getTruncatedAddress in interface AddressSpace
        Parameters:
        offset - the offset for the new address.
        isAddressableWordOffset - if true the specified offset is an addressable unit/word offset, otherwise offset is a byte offset. See AddressSpace.getAddressableUnitSize() to understand the distinction (i.e., wordOffset = byteOffset * addressableUnitSize).
        Returns:
        address with given byte offset truncated to the physical space size

      • subtractWrap

        public Address subtractWrap​(Address addr,
                            long displacement)
        Description copied from interface: AddressSpace
        Creates a new address by subtracting displacement from addr's offset.
        Specified by:
        subtractWrap in interface AddressSpace
        Parameters:
        addr - the original address. The new address will wrap in a manner that depends on the address space. For a generic address space this will wrap at the extents of the address space. For a segmented address space it will wrap at the extents of the segment.
        displacement - the displacement to subtract.
        Returns:
        a new address created by subtracting the displacement from addr.offset.
        See Also:
        AddressSpace.subtractWrap(ghidra.program.model.address.Address, long)

      • subtractWrapSpace

        public Address subtractWrapSpace​(Address addr,
                                 long displacement)
        Description copied from interface: AddressSpace
        Creates a new address by subtracting the displacement from the given address. If the offset is greater than the max offset of the address space, the high order bits are masked off, making the address wrap. For non-segmented addresses this will be the same as subtractWrap(). For segmented addresses, the address will wrap when the 20 bit (oxfffff) offset is exceeded, as opposed to when the segment offset is exceeded.
        Specified by:
        subtractWrapSpace in interface AddressSpace
        Parameters:
        addr - the address to subtract the displacement from.
        displacement - the displacement to subtract.
        Returns:
        The new Address formed by subtracting the displacement from the specified address.
        See Also:
        AddressSpace.subtractWrapSpace(ghidra.program.model.address.Address, long)

      • addWrap

        public Address addWrap​(Address addr,
                       long displacement)
        Description copied from interface: AddressSpace
        Creates a new address by adding displacement to the given address. The resulting address may wrap. The new address will wrap in a manner that depends on the address space. For a generic address space this will wrap at the extents of the address space. For a segmented address space it will wrap at the extents of the segment.
        Specified by:
        addWrap in interface AddressSpace
        Parameters:
        addr - the original address.
        displacement - the displacement to add.
        Returns:
        the new address created by adding displacement to addr.offset.
        See Also:
        AddressSpace.addWrap(ghidra.program.model.address.Address, long)

      • addWrapSpace

        public Address addWrapSpace​(Address addr,
                            long displacement)
        Description copied from interface: AddressSpace
        Creates a new address by adding the displacement to the given address. If the offset is greater than the max offset of the address space, the high order bits are masked off, making the address wrap. For non-segmented addresses this will be the same as addWrap(). For segmented addresses, the address will wrap when the 20 bit (oxfffff) offset is exceeded, as opposed to when the segment offset is exceeded.
        Specified by:
        addWrapSpace in interface AddressSpace
        Parameters:
        addr - the address to add the displacement to.
        displacement - the displacement to add.
        Returns:
        The new Address formed by adding the displacement to the specified addresst.
        See Also:
        AddressSpace.addWrapSpace(ghidra.program.model.address.Address, long)

      • addNoWrap

        public Address addNoWrap​(GenericAddress addr,
                         java.math.BigInteger displacement)
                  throws AddressOverflowException
        Description copied from interface: AddressSpace
        Creates a new address by adding displacement to the given address. The new address will NOT wrap!
        Specified by:
        addNoWrap in interface AddressSpace
        Parameters:
        addr - the original address.
        displacement - the displacement to add.
        Returns:
        The new address created by adding displacement to addr.offset.
        Throws:
        AddressOverflowException - if the addition would cause a wrap,

      • isValidRange

        public boolean isValidRange​(long byteOffset,
                            long length)
        Description copied from interface: AddressSpace
        Check the specified address range for validity within this space. Segmented spaces will restrict a range to a single segment.
        Specified by:
        isValidRange in interface AddressSpace
        Returns:
        true if range is valid for this space

      • compareTo

        public int compareTo​(AddressSpace space)
        Specified by:
        compareTo in interface java.lang.Comparable<AddressSpace>
        See Also:
        Comparable.compareTo(java.lang.Object)

      • equals

        public boolean equals​(java.lang.Object obj)
        Overrides:
        equals in class java.lang.Object
        See Also:
        Object.equals(java.lang.Object)

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object
        See Also:
        Object.hashCode()

      • testAddressSpace

        protected void testAddressSpace​(Address addr)

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
        See Also:
        Object.toString()

      • truncateOffset

        public long truncateOffset​(long offset)
        Description copied from interface: AddressSpace
        Truncate the specified byte offset within this space to produce a valid offset.
        Specified by:
        truncateOffset in interface AddressSpace
        Parameters:
        offset - any byte offset
        Returns:
        truncated byte offset
        See Also:
        AddressSpace.truncateOffset(long)

      • truncateAddressableWordOffset

        public long truncateAddressableWordOffset​(long wordOffset)
        Description copied from interface: AddressSpace
        Truncate the specified addressable unit/word offset within this space to produce a valid offset.
        Specified by:
        truncateAddressableWordOffset in interface AddressSpace
        Parameters:
        wordOffset - any addressable unit/word offset
        Returns:
        truncated word offset
        See Also:
        AddressSpace.truncateOffset(long)

      • isMemorySpace

        public boolean isMemorySpace()
        Description copied from interface: AddressSpace
        Returns true if this space represents a memory address. NOTE: It is important to make the distinction between Loaded and Non-Loaded memory addresses. Program importers may create memory blocks associated with Non-Loaded file content which are not associated with processor defined memory regions. While Loaded file content is placed into memory blocks which are associated with specific memory address spaces defined by the processor language specification.
        Specified by:
        isMemorySpace in interface AddressSpace
        See Also:
        AddressSpace.isMemorySpace()

      • isLoadedMemorySpace

        public boolean isLoadedMemorySpace()
        Description copied from interface: AddressSpace
        Returns true if this space represents represents a Loaded Memory region (e.g., processor RAM).
        Specified by:
        isLoadedMemorySpace in interface AddressSpace

      • isNonLoadedMemorySpace

        public boolean isNonLoadedMemorySpace()
        Description copied from interface: AddressSpace
        Returns true if this space represents represents a Non-Loaded storage region for retaining non-loaded file data (e.g., OTHER)
        Specified by:
        isNonLoadedMemorySpace in interface AddressSpace

      • setShowSpaceName

        public void setShowSpaceName​(boolean b)

      • hasMappedRegisters

        public boolean hasMappedRegisters()
        Description copied from interface: AddressSpace
        Returns true if this space has registers that are mapped into it. This means that registers could actually have pointers to them.
        Specified by:
        hasMappedRegisters in interface AddressSpace
        Returns:
        true if this space has any registers mapped in it.
        See Also:
        AddressSpace.hasMappedRegisters()

      • setHasMappedRegisters

        public void setHasMappedRegisters​(boolean hasRegisters)
        Tag this memory space as having memory mapped registers
        Parameters:
        hasRegisters - true if it has registers, false otherwise