If you are working on answering a frequently asked question, please add it to FAQsInProgress.

How do I ...?

• 1.

• /KernelCompilation How do I compile a kernel?

• 2.

• /KernelCrossCompilation How do I cross compile a kernel?

• 3.

• /DisklessImages An Introduction to Diskless Booting.

• 4.

• /HowToApplyAPatch How do I apply a patch?

• 5.

• KernelHackingTools Are there any good IDEs? How do I handle all this code?

• 6.

• /CompileVendorDriver How do I compile a 3rd party device driver ?

• 7.

• /LinuxKernelModuleCompile How can I compile a Linux Kernel Module ?

• 8.

• /LinuxKernelDebug101 Whats the easiest way to debug ?

• 9.

• CareerAdvice How do I get a job as kernel hacker?

• 10.

• UpstreamMerge How do I get my code into the upstream kernel?

Kernelnewbies questions

• 1.

• /VariousKernelTrees What are the various kernel trees for ?

• 2.

• /WhereDoIBegin Where do I begin?

• 3.

• /People on KernelNewBies Who can I find on #kernelnewbies?

• 4.

• /DoINeedToKnowAssembler Do I need to know assembler to hack the kernel?

• 5.

• /DoINeedToKnowHardware Do I need to know a lot about hardware to hack the kernel?

• 6.

• DoesNotWork I built my own kernel, but it does not work. What's the problem?

Kernel hacking

• 1.

• /VariousKernelTrees What are the various kernel trees for ?

• 2.

• /System.map What is the System.map file?

• 3.

• /MajorMinor What major/minor does XXX have ?

• 4.

• /CodingStyle What coding style should I use?

• 5.

• /LikelyUnlikely What means the macros likely() and unlikely() ?

• 6.

• /Preemption What does preemption mean ? Is it available under Linux ?

• 7.

• /LibraryFunctionsInKernel Can I use library functions in the kernel ?

• 8.

• /SyscallTrace How do I intercept system calls ?

• 9.

• /LinkedLists How does the kernel implements linked lists?

• 10.

• /WhyWritingFilesFromKernelIsBad Why reading/writing files from the kernel is bad, and how to do otherwise ?

Linux kernel gotchas

• 1.

• /get current How does get_current() work?

• 2.

• /current How does the current macro helps you access your process-related record?

• 3.

• /ExternAndStaticInlineVariable What's the difference between extern and static inline?

• 4.

• /DoWhile0 Why do a lot of #defines in the kernel use do { ... } while (0)?

• 5.

• /LikelyUnlikely What do the macros likely() and unlikely() mean?

• 6.

• /ContainerOf What is container_of ? How does it work ?

• 7.

• /InitExitMacros What are the init and exit macros ?

• 8.

• /WhereIs bad udelay Now, where is bad_udelay defined?

• 9.

• /asmlinkage What is asmlinkage ?

• 10.

• /down What is that jmp 1b doing out there?

• 11.

• /TestWpBit test_wp_bit magic, or how exception fixups work.

• 12.

• /BUG How does BUG() work?

• 13.

• /StackTrace
  1. Why is there a function on my stack trace that does not get called?
  2. How do I manually get a stack trace?

• 14.

• BootSectorAndKernelImage Why does the kernel no longer directly boot from floppy?

• 15.

• /FastpathAndSlowpath What is the difference between terms: "Fast path" and "Slow path" ?

Hardware Questions

• 1.

• /HyperthreadingDoesNotWork My CPU says it can do hyperthreading. Why do I only see one thread?

• CategoryFAQ