An official release of the set of utilities mmc-utils 1.0 has been announced, catering to low-level storage devices such as EMMC, SD, and SDIO from user space. This release marks the first official release of the project, which has been in development since 2012. The code is written in the language of si and is distributed under the GPLV2 license.
These utilities provide the capability to read CSD registers (card parameters), CID (card identifier), and SCR (card configuration). They also offer features for protection from temporary or permanent data loss, as well as settings for authentication and configuration specific to EMMC devices. These features include sector size configuration, BKOPS, cache control, and hardware reset.
It is important to note that these utilities require a system with a “real” MMCHCI host to operate effectively. Devices such as USB cartriders, which provide access to storage cards in the form of “USB Mass Storage”, are not compatible as they do not support the sending of MMC commands.