IDA SDK - Interactive Disassembler Module SDK
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This SDK should be used with IDA kernel version 4.8 Build 847
This package allows you to write:
- processor modules
- input file loader modules
- plugin modules (including the
processor module extension plugins)
Please read read through whole file before continuing!
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What you need:
To create 32bit or 64bit Win32 modules: Borland C++ Builder v4.0
or free BCC v5.5
or Visual C++ >= v6.0
or GNU C++ compiler
To create 32bit or 64bit Linux modules: GNU C++ compiler
The Visual C++ users should refer to install_visual.txt for the explanations
how to install.
The CBuilder visual environment users should refer to install_cb.txt for the
explanations how to install (only for the development of plugins using the
visual components).
For installation under Linux, please refer to install_linux.txt
All others should refer to install_make.txt.
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A quick tour on header files:
AREA HPP class 'area'. This class is a base class for
'segment_t' and 'srarea_t' (segment register) classes.
This class keeps information about various areas
of the disassembled file.
AUTO HPP auto-analysis related functions
BYTES HPP Functions and definitions which describe each byte
of the disassembled program: is it an instruction,
data, operand types etc.
DBG HPP Debugger API for debugger users
DISKIO HPP file i/o functions
See file pro.h and fpro.h for additional system functions
ENTRY HPP List of entry points to the program being
disassembled.
ENUM HPP Enumeration types in the disassembled program
EXPR HPP IDC language functions.
FIXUP HPP information about relocation table of the program.
FPRO H Alternative set of system-indenendent file i/o
functions. These functions do check errors but never
exit even if an error occurs. They return extended
error code in qerrno variable.
You must use these functions, not functions from
stdio.h
FRAME HPP Local variables, stack trace
FUNCS HPP Functions in the disassembled program
HELP H Help subsystem. This subsystem is not used in
IDP files. I put it just in case.
IDA HPP the 'main' header file of IDA project.
This file should be included in all source files.
In this file the 'inf' structure is
defined: it keeps all parameters of the disassembled
file.
IDD HPP Debugger plugin API for debugger module writers
IDP HPP the 'main' header file of IDP modules.
2 structures are described here:
processor_t - description of processor
asm_t - description of assembler
Each IDP has one processor_t and several asm_t structures
IEEE H IEEE floating point functions
INTEL HPP header file from the ibm pc module.
for information only, it will not compile
because it contains references to internal files!
INTS HPP predefined comments
KERNWIN HPP various functions to interact with the user.
Also, some functions to process strings are kept in
this header.
LINES HPP generation of source (assembler) lines and long
comment lines. variables controlling the exact time
and place to generate xrefs, indented comments etc.
shouldn't be used in simple IDP modules.
You must use these function instead of functions
from stdlib.h
NALT HPP some predefined netnode array indexes used by the
kernel. these functions should not be used directly
since they are very low level.
NAME HPP names: rename, unname bytes etc.
NETNODE HPP the lowest level of access to the database. Modules
can use this level to keep some private inforation
in the database. Here is a short description of
the concept:
the database consists of 'netnodes'.
The netnodes are numbered by 32-bit integers
and may have:
- a name (max length is MAXNAMESIZE-1)
- a value (a string)
- sparse arrays of values:
Each sparse array has a 8-bit tag. Therefore,
we can have 256 sparse arrays in one netnode.
Only non-zero elements of the arrays are stored in
the database. Arrays are indexed by 32-bit or 8-bit
indexes. You can keep any type of information in
an array element. The size of an element is limited
by MAXSPECSIZE. For example, you could have an
array of addresses that have been patched by the user:
:
The array is empty at the start and will
grow as the user patches the input file.
There are 2 predefined arrays:
- strings (supval)
- longs (altval)
The arrays don't need to be declared or created
specially. They implicitly exist at each node.
To save something into an array simply write
to the array element (altset or supset functions)
There are no limitations on the size or number of
netnode arrays.
OFFSET HPP functions that work with offsets.
PRO H compiler related stuff and some system-independent functions
QUEUE HPP queue of problems.
SEGMENT HPP program segmentation
SRAREA HPP segment registers. If your processor doesn't have
segment registers, you don't need this file.
STRUCT HPP Structure types in the disassembled program
TYPEINF HPP Type information in the program
UA HPP This header file describes insn_t structure called
cmd: this structure keeps a disassembled instruction
in the internal form. Also, you will find here
helper functions to create output lines etc.
VA HPP Virtual array. Used by other parts of IDA.
IDP module don't use it directly.
VM HPP Virtual memory. Used by other parts of IDA.
IDP module don't use it directly.
XREF HPP cross-references.
All functions usable in the modules are marked by the "ida_export" keyword.
There are some exported functions that should be not used except very cautiously
like setFlags() and many functions from nalt.hpp, for example.
In general, try to find a high-level counterpart of the function in these cases.
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Libraries
IDA LIB - import library with all functions exported from the kernel
There are several different versions of this file, one for each platform.
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Description of the processor module example
The module disassembles an instruction in several steps:
- analysis (decoding) file ana.cpp
- emulation file amu.cpp
- output file out.cpp
The analyser (ana.cpp) should be fast and simple: just decode an
instruction and fill the 'cmd' structure. The analyser will always be called
before calling emulator and output functions. If the current address
can't contain an instruction, it should return 0. Otherwise, it returns
the length of the instruction in bytes.
The emulator and outputter should use the contents of the 'cmd' array.
The emulator performs the following tasks:
- creates cross-references
- plans to disassemble subsequent instructions
- create stack variables (optional)
- tries to keep track of register contents (optional)
- provides better analysis method for the kernel (optional)
- etc
The outputter produces a line (or lines) that will be displayed on
the screen.
It generates only essential part of the line: line prefix, comments,
cross-references will be generated by the kernel itself.
To generate a line, MakeLine() or printf_line() should be used.
MAKEFILE - makefile for a processor module
The DESCRIPTION line
should contain names of processors handled by this IDP
module, separated by colons. The first name is description
of whole module (not a processor name).
STUB - MSDOS stub for the module
ANA CPP - analysis of an instruction: fills the cmd structure.
EMU CPP - emulation: creates xrefs, plans to analyse subsequent
instructions
INS CPP - table of instructions.
OUT CPP - generate source lines.
REG CPP - description of processor, assemblers, and notify() function.
This function is called when certain events occur. You
may want to have some additional processing of those events.
IDP DEF - the module description for the linker.
I51 HPP - local header file. you may have another header file for
you module.
INS HPP - list of instructions.
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And finally:
I recommend to study the samples, compile and run them.
Limitations on the modules:
- for the dynamic memory allocation: please use qalloc/qfree()
while you are free to use any other means, these functions
are provided by the kernel and everything allocated by the
kernel should be deleted using qfree()
- for the file i/o: never use functions from stdio.h.
Use functions from fpro.h instead.
If you still want to use the standard functions, never pass
FILE* pointer obtained from the standard functions to the kernel
and vice versa.
- the exported descriptor names are fixed:
processor module LPH
loader module LDSC
plugin module PLUGIN
Usually I write a new processor module in the following way:
- copy the sample module files to a new directory
- first I edit INS.CPP and INS.HPP files
- write the analyser ana.cpp
- then outputter
- and emulator (you can start with an almost empty emulator)
- and describe the processor & assembler, write the notify() function
Naturally, it is easier to copy and to modify example files than to write
your own files from the scratch.
Debugging:
You can use the following debug print functions:
deb() - display a line in the messages window if -z command
line switch is specified. You may use debug one of:
IDA_DEBUG_IDP, IDA_DEBUG_LDR, IDA_DEBUG_PLUGIN
msg() - display a line in the messages window
warning() - display a dialog box with the message
To stop in the debugger when the module is loaded, you may use the
__emit__(0xCC) construct in the module initialization code.
(__asm _emit 0xCC; for Visual C++)
BTW, you can save all lines appearing in the messages window to a file.
Just set an enviroment variable:
set IDALOG=ida.log
I always have this variable set, it is great help in the development.
The SDK support is not included in the IDA Pro purchase but
you can subscribe for the extended SDK support:
http://www.datarescue.com/idabase/idaorder.htm
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Information on the compilers
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Borland:
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BCC 5.5 (free)
download from www.borland.com/bcppbuilder/freecompiler/
Borland C++ Builder v4.0, v5.0 (commercial)
Microsoft:
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.NET framework SDK (free, for CL.EXE, LINK.EXE)
+ .NET framework (free, only to install .NET framework SDK)
+ Platform SDK (free, for NMAKE.EXE):
Core SDK - build environment (for NMAKE.EXE and C headers)
downloads at:
www.microsoft.com/italy/msdn/download/frameworksdk.asp
www.microsoft.com/msdownload/platformsdk/sdkupdate/
Visual C++ v6.0 (commercial)
GNU:
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MinGW (free) + MSYS (free, needed for GNU MAKE)
download at http://www.mingw.org/
CYGWIN (free)
download at http://www.cygwin.com/