Explore the evolution of SD and eMMC standards, focusing on new speed modes and their implementation in the Linux kernel. Delve into the hardware-level workings of SD and eMMC standards, with particular emphasis on advanced speed modes like SDR12, SDR25, SDR50, SDR104, DDR52, HS200, and HS400. Examine Linux's support for these standards, including developments in the MMC core and new drivers. Gain insights into current limitations and future expectations for Linux support of SD and eMMC technologies. Learn from Gregory Clement, an experienced embedded Linux engineer and trainer, who shares his expertise in porting and integrating various hardware architectures, including his work on Marvell Armada SoCs and mainline contributions to SD/eMMC controller support for high-speed modes.