MeatySkeleton linking libc libraries

[MuchLearning]

I've been stepping through the MeatySkeleton Tutorial trying to understand each piece. I think I've got most of it down but I don't understand how the functions included in libc get linked when compiling the kernel.

I'm trying to recreate my own version of MeatySkeleton and when compiling the kernel I get 'undefined reference to ...' for anything from the libc directory.

[iansjack]

As the tutorial explains, if you want to use kind functions you need to create your own kind.

[MuchLearning]

I have written headers and sources for the functions I am trying to use. With all headers installed my sysroot looks something like

Code: Select all

sysroot/
    usr/
        include/
            stdio.h
            terminal.h
        lib/
            libk.a

And the function I'm attempting to use, printf, comes from stdio.h. Does this mean libk.a is not getting created correctly? Is that where the sources are being linked from?

*Edit*: the libk.a archive does contain printf.libk.o so I'm not sure what is happening.

[StudlyCaps]

Do you have -lk in your $LIBS variable in kernel/Makefile?

edit: Or more precisely, when you build the kernel, is gcc being passed -lk.

[MuchLearning]

Do you have -lk in your $LIBS variable in kernel/Makefile?

StudlyCaps you indeed have the studliest of caps. I must have missed this flag.

What does it do? I can't find anything about what it does anywhere.

[iansjack]

It specifies that you want to link libk. You don't need to specify -lc as it is assumed.

In general, if you want to link libfoo you need -lfoo.

[StudlyCaps]

You know I do

It tells the linker to link against a library named libk.

edit: beaten!