Include a Troubleshooting chapter

Fixes #39
Fixes #45
Fixes #48

src/SUMMARY.md

@@ -23,4 +23,5 @@
 - [A simple VGA driver]()
 - [Keyboard input]()
 -----------
-[Appendix A: Numeral Systems](appendix/numeral-systems.md)
+[Appendix A: Troubleshooting](appendix/troubleshooting.md)
+[Appendix B: Numeral Systems](appendix/numeral-systems.md)

src/appendix/troubleshooting.md

@@ -0,0 +1,71 @@
+# Appendix A: Troubleshooting
+
+In this appendix, we will cover common errors and their solutions for
+various chapters of the book.
+
+## Chapter 3
+
+Here are various solutions to issues you may run into in Chapter 3:
+
+### Error: no multiboot header found
+
+When booting up your kernel, QEMU may print out a message like this:
+
+```text
+error: no multiboot header found
+error: you need to load the kernel first
+```
+
+This can happen for a number of reasons, but is often caused by typo-ing
+something. Double check your code against the examples and make sure that
+they’re _identical_, especially things like magic numbers. They’re easy to
+mis-type.
+
+### Could not read from CDROM (code 0009)
+
+On a system that uses EFI to boot, you may see an error like this:
+
+```text
+$ qemu-system-x86_64 -cdrom os.iso
+Could not read from CDROM (code 0009)
+```
+
+The solution may be to install the `grub-pc-bin` package:
+
+```bash
+$ sudo apt-get install grub-pc-bin
+```
+
+### xorriso : FAILURE : Cannot find path ‘/efi.img’ in loaded ISO image
+
+When building the ISO, you may see a message like this:
+
+```text
+xorriso : FAILURE : Cannot find path ‘/efi.img’ in loaded ISO image
+```
+
+The solution may be to install the `mtools` package:
+
+```bash
+$ sudo apt-get install mtools
+```
+
+### Could not initialize SDL(No available video device) - exiting
+
+When booting your kernel in QEMU, you may see an error like this:
+
+```text
+Could not initialize SDL(No available video device) - exiting
+```
+
+You can pass an extra flag to QEMU to not use SDL, `-curses`:
+
+```bash
+$ qemu-system-x86_64 -curses -cdrom os.iso
+```
+
+Or, try installing SDL and its development headers:
+
+```bash
+$ sudo apt-get install libsdl2-dev
+```