how to generate bitcode?

hello,

1-Can you please guide me on how to generate LLVM IR for the Linux kernel step by step?
is this the command which you used?
```
sudo make CC="clang -S -emit-llvm" HOSTCC="clang -S -emit-llvm" defconfig
sudo make CC="clang -S -emit-llvm" HOSTCC="clang -S -emit-llvm"  
```
2- how can i merge these files to one with `llvm-link`?

Thank you