PSX MND/SYM parser in Golang

Parse Playstation 1 symbol files (*.SYM files with MND\1 header).

Installation

go get -u github.com/mefistotelis/psx_mnd_sym/cmd/sym_dump

Usage

The default output of sym_dump is in Psy-Q format and is identical to the DUMPSYM.EXE tool of the Psy-Q SDK.

sym_dump DIABPSX.SYM
# Output:
#
# Header : MND version 1
# Target unit 0
# 000008: $800b031c overlay length $000009e4 id $4
# 000015: $800b031c overlay length $00000004 id $5
# 000022: $80139bf8 overlay length $00023234 id $b
# 00002f: $80139bf8 overlay length $00029dcc id $c
# 00003c: $80139bf8 overlay length $0002a228 id $d
# 000049: $80139bf8 overlay length $0001ec70 id $e
# 000056: $00000000 94 Def class TPDEF type UCHAR size 0 name u_char

The tool can also dump C headers with type definitions, variable and function declarations.

sym_dump -c DIABPSX.SYM

IDA Python scripts can be created as well.

sym_dump -ida DIABPSX.SYM

More options can be discovered by triggering help screen.

sym_dump --help

Preparing IDA Pro project

One of the most prominent features of this tool is the support for IDA Pro scripts. Here is a tutorial on how to get IDA project with all the debug data loaded.

1. Open the PSX executable

Open the SL* binary in IDA Pro. Since IDA knows the format, it should propose the correct MIPS processor:

MIPS little endian, for Playstation 1
MIPS R5900 little endian, for Playstation 2

If there are multiple binary overlays used by your application, you should use File -> Load file -> Another binary file to load the .BIN files as well. Unless you want to have a separate IDA project for each overlay, that's fine as well.

2. Setup the compiler

IDA has no special entry for the Sony SDK compiler; in Options -> Compiler..., you can select either Visual C++ or GNU C++, as the important values are identical in these two.

3. Load type definitions

Now that IDA knows sizes of basic types and alignment from compiler options, you can load the header file with type definitions. Use File -> Load file -> Parse C header file....

Often the generated types.h will have some ordering issues - you can edit it by hand, reordering structs and unions until IDA is happy to load all the types.

4. Load symbol names and types

Now as types are loaded, you can ask IDA to execute the Python scripts. Use File -> Script file.... The order you load them should not matter. There are 3 files to load:

make_psx.py sets names of all known symbols
set_funcs.py sets function signatures
set_vars.py sets types of global variables

5. Start your analysis

After you load all the files, you are ready to start analyzing the code. If some functions or globals are not named correctly at this point, they were probably not included in the .SYM file (ie. precompiled libraries compiled into your executable). But you may compare the addresses with SYMDUMP.EXE output to make sure - that output contains everything the .SYM file had, in the same order, without much interpretation.

mefistotelis / psx_mnd_sym