10.5. Chapter Summary The Memory Technology Devices (MTD) subsystem provides support for memory devices such as Flash memory in the Linux kernel. MTD must be enabled in your Linux kernel configuration. Several figures in this chapter detailed the configuration options. As part of the MTD kernel configuration, the proper Flash driver(s) for your Flash chips must be selected. Figure 10-4 presented the collection of chip drivers supported in a recent Linux kernel snapshot. Your Flash memory device can be managed as a single large device or can be divided into multiple partitions. Several methods are available for communicating the partition information to the Linux kernel. These include Redboot partition information, kernel command-line parameters, and mapping drivers. A mapping driver, together with definitions supplied by your architecture-specific board support, defines your Flash configuration to the kernel. MTD comes with a number of user space utilities to manage the images on your Flash devices. The Journaling Flash File System 2 (JFFS2) is a good companion to the MTD subsystem for small, efficient Flash-based file systems. In this chapter, we built a JFFS2 image and mounted it as root on our target device.
10.5.1. Suggestions for Additional Reading MTD Linux home page www.linux-mtd.infradead.org/ Redboot user documentation http://ecos.sourceware.org/ecos/docs-latest/redboot/redboot-guide.html Common Flash Memory Interface Specification AMD Corporation www.amd.com/us-en/assets/content_type/DownloadableAssets/cfi_r20.pdf |