Lecture explaining trap handling mechanisms for system calls, interrupts, and faults; kernel vs user mode execution; trap instructions and IDT; kernel stacks; and context switching mechanism including saving/restoring process contexts and OS scheduler operations.

Lecture on memory allocation system calls including sbrk/brk for heap expansion, mmap for memory mapping (anonymous and file-backed), malloc implementation, heap allocators (variable-sized, segregated lists, slab allocators, buddy allocation), and free list management.

Lecture on Unix process management system calls including fork() for process creation, exec() for running executables, exit() for termination, wait() for reaping zombie children, and shell command execution using these system calls with examples.

Introduction to OS memory management covering virtual addressing, address spaces, MMU address translation, base and bounds, segmentation, paging with page tables, TLB for caching translations, and the role of OS versus hardware in memory management.

Lecture covering Linux network stack including interrupt handling (top/bottom half), device drivers, NIC DMA operations, NAPI polling, and fast I/O techniques like kernel bypass (DPDK), eBPF/XDP for high-performance packet processing and network optimization.