• FAQ

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?

1. • 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?

1. • /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 ?

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

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

3. • /BUG How does BUG() work?

4. • /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?

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

6. • /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