FoundryOS/docs/Debugging/DEBUGGING.md

Debugging the Kernel

Here we will add some helpful tips on debugging the kernel.

Disassembling a public function

To disassemble a public function, first we need a symbol in the public symbol table, so start by making the function fully public (including any parent modules). Do this as though you are trying to make a public function for a library crate (this includes the kernel crate). Simply mark the function and any parent modules as public, up until the point of lib.rs (kernel link).

Then, we need to find the specific demangled symbol to disassemble, because the default objdump output can be very verbose.

# Change as required, I pipe to less and /SEARCH FOR FUNCTION HERE.
nm --demangle ./build/target/x86_64-kernel/debug/kernel | less
# Now just paste the symbol where it says YOUR_SYMBOL_HERE and profit. Use -Mintel for Intel assembly syntax.
objdump -Matt --source --line-numbers --visualize-jumps ./build/target/x86_64-kernel/debug/kernel --demangle=rust --disassemble="YOUR_SYMBOL_HERE"