private long getPreLinkImageBase() {
		if (preLinkImageBase != null) {
			return preLinkImageBase;
		}
		preLinkImageBase = -1L;
		try {
			long fileLength = reader.getByteProvider().length();

			// not enough bytes
			if (fileLength < 8) {
				return -1;
			}
			int preLinkImageBaseInt = reader.readInt(fileLength - 8);
			String preLinkMagicString = reader.readAsciiString(fileLength - 4, 4).trim();

			if (preLinkMagicString.equals("PRE")) {
				preLinkImageBase = Integer.toUnsignedLong(preLinkImageBaseInt);
			}
		}
		catch (IOException e) {
			Msg.error(this, "Elf prelink read failure", e);
		}
		return preLinkImageBase;
	}
Some elfs can get pre-linked to an OS.
    At the very end a "PRE " string is appended with the image base load address
    set.  Try there if none of the images told us where to load.
@return -1 - if the imagebase is not a pre-link image base.
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/elf/ElfHeader.java