Writing a Kernel in C. So far, your only experience in operating system writing might have been writing a boot loader in assembly. If you wrote it from scratch it might have taken you several weeks (at least), and you might be wishing there was an easier way. Well: there is, particularly if you are already familiar with the C programming language. Even if you’re not familiar with C (and you already know some other high-level language), it’s well worth learning it, because it’s trivial to start coding your kernel in C. It’s a matter of getting a few details correct and having the. | Writing a Kernel in C Writing a Kernel in C Tim Robinson @ http Introduction So far your only experience in operating system writing might have been writing a boot loader in assembly. If you wrote it from scratch it might have taken you several weeks at least and you might be wishing there was an easier way. Well there is particularly if you are already familiar with the C programming language. Even if you re not familiar with C and you already know some other high-level language it s well worth learning it because it s trivial to start coding your kernel in C. It s a matter of getting a few details correct and having the right tools. The C Programming Language C was originally designed as a low-level HLL Unix kernels have traditionally been written in C and its main advantages are its portability and its closeness to the machine. It s easy to write non-portable programs in C but given some knowledge of the language it s possible to code with portability in mind. There s nothing special about compiled C code that makes it different to assembly - in fact your assembler is nothing more than a low-level compiler one in which statements translate directly into machine opcodes. Like any other high-level language C makes the code more abstract and separates you from the machine more however C doesn t place too many restrictions on the code you write. Tools There are two main software components involved in generating machine-executable code from C source code a compiler and a linker. The compiler does most of the work and is responsible for turning C source code into object files that is files which contain machine code and data but don t constitute a full program on their own. Many C compilers have an option where they generate an executable file directly from the source code but in this case the compiler probably just invokes the linker internally. The linker bundles all the object files together patches the references .
