This conference talk explores the challenges of PCIe controller drivers in Linux systems without BIOS configuration, particularly on ARM platforms. Learn why many current controller drivers are sub-optimal and discover better approaches to handling PCIe bus configuration. Explore strategies for eliminating controller drivers entirely through bootloader assistance, or alternatively, how to rewrite them efficiently by leveraging existing infrastructure and avoiding unnecessary address translations (with a focus on ECAM). Gain insights into improving Linux kernel development practices for PCIe controller implementation across non-x86 platforms.