Introduction

Introduction

Currently, the eCos USB-Mass Storage Device (MSD) slave package provides support only for the SCSI transparent command set. The package flexibility allows future extension for other sub-class, .i.e. RBC, UFI etc.. The package requires the actual storage media to use the eCos disk interface. Disk sector size is assumed 512 bytes.

The USB-MSD package is not tied to any specific hardware. It requires the presence of USB hardware on the target and a suitable device driver to make endpoints available for this code to use. The configuration system cannot load the eCos package automatically for specific targets, in the way that a USB device driver or an ethernet driver can be loaded automatically. Instead, the package has to be added explicitly. When using the command line tools this will involve an operation like the following:

        $ ecosconfig add usbs_msd
      

Typically, this will automatically cause the USB device driver to become active. The USB-Mass Storage Device driver runs as a thread, therefore requires the kernel package to be active. To start the MSD interface, user must call the usbs_msd_start() function. No other user intervention is required. The MSD driver will interact directly with the storage media. Care should be taken not to mount/use the filesystem present on the media while used as a mass storage. This could potentially damage the filesystem.