JOS is a teaching OS using by MIT/Stanford/UCLA OS course. There are several hands-on exercises in it.

The code in this git repo comes from UCLA OS course website: http://www.cs.ucla.edu/~kohler/class/06f-aos/index.html

JOS-vmx(JOS Virtual Machine eXtensions) is another hands-on exercise, which aims at turning JOS into a hypervisor by utilizing hardware assisted virtualization(ex. Intel-vt).

• Have read the Chapter 19 INTRODUCTION TO VIRTUAL-MACHINE EXTENSIONS of Intel Software Developer's Manual Volume 3B System Programming Guide, Part 2(3B in brief).
• Have finished JOS Lab2.
• Have known what is the Matrix.
• Have EPT and Unrestricted guest features present in the CPU. This is not necessary if you use bochs emulator instead.

• Step1: > make
• Step2: > make install-grub
• Step3: Add a JOS entry in system grub list
• Step4: Reboot your computer
• Step5: Enter JOS in grub

alternative:

• Step1: Download bochs-2.4.5
• Step2: ./configure --enable-debugger --enable-vmx=2 --enable-x86-64 --prefix=/usr
• Step3: make & make install
• Following process is just the same as what we did in JOS lab.

"When you have learned to snatch the error code from the trap frame, it will be time for you to leave." --- 《The Tao Of Programming》

"When you have learned to create the MATRIX, it will be time for you to leave." --- Jules Wang

It's easier on everyone if all authors working on a shared code base are consistent in the way they write their programs. We have the following conventions in our code:

• No space after the name of a function in a call For example, printf("hello") not printf ("hello").

• One space after keywords "if", "for", "while", "switch". For example, if (x) not if(x).

• Space before braces. For example, if (x) { not if (x){.

• Function names are all lower-case separated by underscores.

• Beginning-of-line indentation via tabs, not spaces.

• Preprocessor macros are always UPPERCASE. There are a few grandfathered exceptions: assert, panic, static_assert, offsetof.

• Pointer types have spaces: (uint16_t *) not (uint16_t*).

• Multi-word names are lower_case_with_underscores.

• Comments in imported code are usually C /* ... */ comments. Comments in new code are C++ style //.

• In a function definition, the function name starts a new line. Then you can grep -n '^foo' /.c to find the definition of foo.

• Functions that take no arguments are declared f(void) not f().