Beyond PCs and general-purpose embedded systems lie platforms where the Linux boot process has been specialized to an extreme degree. In this installment, we explore three of these unique environments: the security-focused world of Android, the legacy-rich domain of IBM Z mainframes, and the software-defined flexibility of QEMU/KVM virtualization.
The Android boot process is a masterclass in vertical integration, engineered for security and reliability at a massive consumer scale.
Booting Linux on an IBM Z mainframe follows a unique paradigm shaped by decades of mainframe design principles.
In a virtualized environment like QEMU/KVM, the hardware is software-defined, making the boot process a highly configurable abstraction.
Despite their profound differences, these platforms all face common challenges in securing the boot chain and ensuring system updates are reliable. In our final article, we will explore the cross-platform themes of Secure Boot and atomic updates.
This article provides a deep dive into the major scheduler classes, their unique design goals, and the management utilities powering the system.
sched_ext is not a scheduler; it’s a framework that securely connects custom BPF programs to the core kernel. Its architecture consists of four distinct layers that separate responsibilities cleanly.
For decades, general-purpose schedulers like CFS and EEVDF, powered everything from phones to supercomputers. But with complex hardware and specialized software, the “one-size-fits-all” scheduling model began to crack. This tension set the stage for sched_ext.
In this final installment of our series, we synthesize our exploration of diverse Linux boot processes by examining two critical, cross-platform themes: securing the chain of trust and ensuring system resiliency through atomic updates