This text is a practical guide to writing your own x86 operating system. It is designed to give enough help with the technical details while at the same time not reveal too much with samples and code excerpts. We\u2019ve tried to collect parts of the vast (and often excellent) expanse of material and tutorials available, on the web and otherwise, and add our own insights into the problems we encountered and struggled with.<\/p>\n
This book is not about the theory behind operating systems, or how any specific operating system (OS) works. For OS theory we recommend the book\u00a0Modern Operating Systems<\/em>\u00a0by Andrew Tanenbaum\u00a0[1]<\/span>. Lists and details on current operating systems are available on the Internet.<\/p>\n The starting chapters are quite detailed and explicit, to quickly get you into coding. Later chapters give more of an outline of what is needed, as more and more of the implementation and design becomes up to the reader, who should now be more familiar with the world of kernel development. At the end of some chapters there are links for further reading, which might be interesting and give a deeper understanding of the topics covered.<\/p>\n In\u00a0chapter 2<\/a>\u00a0and\u00a03<\/a>\u00a0we set up our development environment and boot up our OS kernel in a virtual machine, eventually starting to write code in C. We continue in\u00a0chapter 4<\/a>\u00a0with writing to the screen and the serial port, and then we dive into segmentation in\u00a0chapter 5<\/a>\u00a0and interrupts and input in\u00a0chapter 6<\/a>.<\/p>\n After this we have a quite functional but bare-bones OS kernel. In\u00a0chapter 7<\/a>\u00a0we start the road to user mode applications, with virtual memory through paging (chapter 8<\/a>\u00a0and\u00a09<\/a>), memory allocation (chapter 10<\/a>), and finally running a user application in\u00a0chapter 11<\/a>.<\/p>\n In the last three chapters we discuss the more advanced topics of file systems (chapter 12<\/a>), system calls (chapter 13<\/a>), and multitasking (chapter 14<\/a>).<\/p>\n","protected":false},"excerpt":{"rendered":"