A fully GPL-compliant solution for installing and running a bootable DiskOnChip flash disk in a Linux-based system is now available directly from M-Systems. The solution is offered in binary form (without source), and provides two approaches to incorporating DiskOnChip into the Linux system:

• Compiled as part of the Linux kernel (“built-in”)
  
• Compiled as a loadable kernel module (“loadable… module”)

Secondly, the DiskOnChip can be used in two ways:

• As a supplemental (non-boot) disk
  
• As a boot disk

Typically, if it is required to use the DiskOnChip for a root file system, compiling the driver as part of the kernel is uncomplicated and requires less additional configuration. However, due to the GNU General Public License (GPL) restrictions, a kernel with the M-System driver built into it cannot be distributed (all source code for the kernel must be available, and the M-Systems software contains some pre-compiled software). Therefore, if it is required to distribute a working solution, then the loadable module implementation must be used.

The M-Systems DiskOnChip solution includes detailed step-by-step procedures for all four possibilities listed above. The loadable module approach, which solves the problem of compliance with GPL, consists of a multi-step process which first accesses the DiskOnChip as a read-only device in order to load the Linux kernel, the DiskOnChip loadable module, and other required files into a RAM disk. Thereafter, the system launches the kernel and installs the DiskOnChip's read/write support via the loadable module, and then proceeds to boot the full Linux system into memory using the DiskOnChip as a boot drive.

The M-Systems DiskOnChip GPL-compliant solution is available for download, here. An installation manual is included within the downloaded driver zip file. Free registration is required prior to download.

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