Package ghidra.app.plugin.assembler

Class AssemblyBuffer

java.lang.Object
ghidra.app.plugin.assembler.AssemblyBuffer
public class AssemblyBuffer extends Object
A convenience for accumulating bytes output by an Assembler

This is most useful when there is not a Program available for assembly. If a program is available, consider using Assembler.assemble(Address, String...) and reading the bytes from the program. If not, or the program should not be modified, then the pattern of use is generally: 

 Address start = space.getAdddress(0x00400000);
 Assembler asm = Assemblers.getAssembler(...);
 AssemblyBuffer buffer = new AssemblyBuffer(asm, start);
 
 buffer.assemble("PUSH R15");
 buffer.assemble("PUSH R14");
 buffer.assemble("PUSH R13");
 ...
 byte[] bytes = buffer.getBytes();
 state.setVar(start, bytes.length, true, bytes);

  • Constructor Details

    • AssemblyBuffer

      public AssemblyBuffer(Assembler asm, Address entry)
      Create a buffer with the given assembler starting at the given entry
      Parameters:
      asm - the assembler
      entry - the starting address where the resulting code will be located

  • Method Details

    • getNext

      public Address getNext()
      Get the address of the "cursor" where the next instruction will be assembled
      Returns:
      the address

    • assemble

      public byte[] assemble(String line) throws AssemblySyntaxException, AssemblySemanticException, IOException
      Assemble a line and append it to the buffer
      Parameters:
      line - the line
      Returns:
      the resulting bytes for the assembled instruction
      Throws:
      AssemblySyntaxException - if the instruction cannot be parsed
      AssemblySemanticException - if the instruction cannot be encoded
      IOException - if the buffer cannot be written

    • emit

      public byte[] emit(byte[] bytes) throws IOException
      Append arbitrary bytes to the buffer
      Parameters:
      bytes - the bytes to append
      Returns:
      bytes
      Throws:
      IOException - if the bufgfer cannot be written

    • getBytes

      public byte[] getBytes()
      Get the complete buffer of bytes

      However used, the bytes should be placed at the entry given at construction, unless the client is certain the code is position independent.

      Returns:
      the bytes