Nintendo Entertainment System (NES) loader module
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Copyright 2006, Dennis Elser (
dennis@backtrace.de)
IDA Pro loader module for Nintendo Enternainment System
(NES) ROM images in iNES file format.
You need IDA Pro 4.9 at least in order to be able to
use this loader. For installation instructions, please
read below.
This loader tells IDA Pro how to correctly load
iNES ROM images. The disassembly is done by the
M6502 processor module coming along with IDA Pro,
which is compatible with the slightly modified
cpu of the NES.
Please note that the real NES hardware memory area
ends after 0xFFFF as it can address 16bit only.
The NES uses several page/bank swapping techniques in
order to load additional ROM banks. However, this
loader reads at most two 16k PRG ROM banks into the
IDA database, because it takes care of the original
memory layout.
This significantly improves the disassembly, but currently
doesn't allow to reassemble the disassembly.
By the way: if you want the IDA wizard to show up
the NES loader under the "Consoles" tab, you can edit
the following files:
file: %idadir%/cfg/templates.xml
add the following lines below under the "Consoles" category:
<template idc:icon="I_ROM" extensions="ROM_NES" loader="nes" processor="m6502">
<xi:include xpointer="xpointer(/ida/templates/wizard[@X='default_w'])"/>
</template>
file: %idadir%/cfg/idagui.cfg
add the following line below under "FILE_EXTENSIONS":
ROM_NES, ".nes Nintendo NES ROM Images", "*.nes"
Copy compiled loader to %idadir%/loaders/nes.ldw
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Note to programmers:
The whole file is stored within the IDA Pro database
by the loader. You can access all parts of the original
file using netnodes.
Example:
The original iNES header is stored in a netnode
(INES_HDR_NODE). You can access the header from a
plugin by reading the netnode's blob as shown below.
Example code:
#include "nes.h"
netnode node(INES_HDR_NODE);
ines_hdr hdr;
node.getblob(&hdr, &INES_HDR_SIZE, 0, 'I');
(c) 2006, Dennis Elser
