Debugging
These are very important guides for understanding the debugging process and how applications work.
Mac OS X Debugging Magic Technical Note (TN2124) (link - PDF Mirror)
iOS Debugging Magic Technical Note (TN2239) (link - PDF Mirror)
Understanding and Analyzing iOS Application Crash Reports (TN2151) (link - PDF Mirror)
Malloc Debug Environment Variables (link - PDF Mirror)
Mach-O Binaries
Mac OS X and iOS use Mach-O file format for executable binaries and shared libraries. It supports multiple architectures in one binary file (Universal or fat binaries).
Mach-O Wikipedia (link)
OS X ABI Mach-O File Format Reference (link - PDF - PDF Mirror)
Mach-O Programming Topics (link - PDF - PDF Mirror)
Analysis
Guides and introductory material to binary analysis.
Analyzing Binaries with Hopper (link)
System ABIs
Calling conventions define how functions and subroutines receive the parameters passed to them from the calling function.
ABI Wikipedia (link)
Calling Conventions Wikipedia (link)
Mac OS X ABI (link - PDF - PDF Mirror)
iOS ABI (link - PDF - PDF Mirror)
Dynamic Library Programming Topics (link - PDF - PDF Mirror) (Companion File - Companion File Mirror)
OS X ABI Dynamic Loader Reference (link - PDF - PDF Mirror)
Language Resources
Language specific knowledge is often required to understand what is going on behind the scenes.
Intel x86 Architecture (PDF - PDF Mirror)
Introduction to x64 Assembly (PDF - PDF Mirror)
ARM Architecture for ARMv7 (PDF Mirror)
ARM Architecture for ARM64 (PDF Mirror)
OS X Assembler Reference (link - PDF - PDF Mirror)
Learn C The Hard Way (link)
The C Library Reference Guide (link)
Objective-C Language (link - PDF - PDF Mirror)
Objective-C Runtime (link - PDF - PDF Mirror)
Further Reading
Collection of blogs and reading resources that give deep insight into how many aspects of languages and system functionality.
NSBlog (link)
Reverse Engineering Mac OS X (link)
Landon's Blog (link)
OS X Internals (link)
Greg Parker's Blog (link)
Ridiculous Fish (link)
Snare's Blog (link)
To The Apple's Core (link)
The Objective-C Runtime: Understanding and Abusing (link)
Tools
Mach-O Binary Analyzers:
MachOViewer (Homepage)
Hex Editors:
Hex Fiend (Homepage)
0xED (Homepage)
Synalyze It! (Homepage)
Disassemblers:
Hopper (Homepage)
IDA (Homepage)
otool (man page)
otx (Homepage)
Decompilers:
Hopper (Homepage)
Hex-Rays (Homepage)
classdump (Homepage)
codedump (i386) (Source ZIP)
Debuggers:
GDB (Not shipped on OS X anymore) (Homepage)
LLDB (Homepage - man page)
PonyDebugger (link)
Memory Editors:
Bit Slicer (Homepage - Source)
Various Command Line Tools:
nm (man page)
strings (man page)
dsymutil (man page)
install_name_tool (man page)
ld (man page)
lipo (man page)
codesign (man page)
hexdump (man page)
dyld_shared_cache (link)
vbindiff (link)
binwalk (link)
xpwntool (link)
objdump (link)
Useful Source Repositories:
Apple Source Code (link)
PLCrashReporter (link)
Mike Ash's Github (link)
Landon Fuller's Github (link)
Jonathan Rentzsch's Github (link)
fG!'s Github (link)
