Advanced Operating Systems

This is the home page for the "Advanced OS" course. Here, you will find (in a badly-organised form) all the material, slides, and information needed to attend the course

For the previous editions of the course, check the old websites (2018, 2019, 2020, and 2022).

Lessons:

• First lesson: 2025/03/06, PC room, 9:30 -> 11:30
  • Introduction to the course
  • Introduction to real-time operating systems
• Second lesson: 2025/03/10, PC room, 9:30 -> 11:30
  • Quick summary about computer architectures and Operating Systems
  • On kernel latencies, again
• Third lesson: 2025/03/13, PC room, 9:30 -> 11:30
• Fourth lesson: 2025/03/24, PC room, 9:30 -> 11:30
• Fifth lesson: 2025/03/27, PC room, 9:30 -> 11:30
• Sixth lesson: 2025/03/31, PC room, 9:30 -> 11:30
• Seventh lesson: 2025/04/02, PC room, 9:30 -> 11:30
• Eighth lesson: 2025/04/07, PC room, 9:30 -> 11:30
• Nineth lesson: 2025/04/10, PC room, 9:30 -> 11:30
• Tenth lesson: 2025/04/14, PC room, 9:30 -> 11:30

Project Ideas

Here are some ideas for possible projects for the exam. Remember to contact me when you chose one.

References:

• List of references to scientific papers
• Some standards about executable formats (useful to implement a loader / ELF parser in a hypervisor or microkernel)
• The Intel CPU manuals, useful to implement bare-metal hypervisors, kernels, and to use Intel's hardware-assisted virtualization technologies

Examples:

• Examples about periodic timers
• Some tests with Xenomai
• Example about using l4re. Follow these instructions to use it.
• Very simple example about trap and emulate, also showing an issue with the x86 ISA not respecting Popek & Goldberg requirements (the instruction to read the "Machine Status Word" register is sensitive but not privileged)
  • Same example, with the guest code separated in a different executable file (as a reference, see how GRUB loads Xen and its Dom0 kernel or how l4re loads its servers)
  • Same example again, this time parsing the ELF format of the guest to load it. Notice how this bare-metal hypervisor has to implement memory management and other functionalities needed by the ELF parser
Simple example about using Intel's VT-x (as a hosted hypervisor or as a bare-metal hypervisor)
• Execution of the hosted hypervisor
• Execution of the bare-metal hypervisor
-->
• Example with KVM
  • Small improvement of the KVM example, separating the guest code in a different executable
  • Patch showing how to handle I/O

Useful Links:

• The Linux kernel
• The Preempt-RT patchset
  • Notes about developing real-time applications
• Dual-kernel systems: Xenomai, EVL, RTAI
• Microkernels: l4re, sel4, Genode, GNU Hurd (based on Mach), Google Zircon (note: "handles" are similar to capabilities), ...
• Hypervisors: Xen, ACRN, Jailhouse, ...
• Some lightweight VMs / VMMs using KVM (see also QEMU's microvm): the Intel cloud hypervisor, Amazon's FireCracker, ...
  • To see a reference simple VMM based on KVM, check TinyEMU or kvmtool
• The Rump Kernels, useful for example to build unikernels based on openbsd source code. Notice that the rumpkernel.org site seems to be down