6 Modify file system details in menuconfig to boot from NAND Flash

  1. Enter the following command to modify the configurations:

    $ make menuconfig

    The configuration window opens.

  2. From the menu, select Filesystem images and press Enter.
    1. In the Filesystem images window, ensure the ubi image containing an ubifs root filesystem checkbox is enabled. If not, select it and press ‘Y’ to enable.
    2. In the Filesystem images window, select physical eraseblock size and press Enter.
    3. Update the physical eraseblock size to 0x40000 and press Enter. The physical erase block size is the NAND Flash block size in bytes.
    4. In the Filesystem images window, select sub-page size and press Enter.
    5. Update the sub-page size to 4096 and press Enter. Some NAND Flash devices support sub-pages,and some do not. Those that do not must be updated with the actual page size as the sub-page size.
    6. In the Filesystem images window, ensure ubifs root filesystem is enabled. If not, select it and press ‘Y’ to enable.
    7. In the Filesystem images window, select logical eraseblock size and press Enter.
    8. Update the logical eraseblock size to 0x3E000 and press Enter. The logical eraseblock size is calculated by subtracting two pages from the physical eraseblock size (LEB = PEB – 8192). Each of the two pages contains an EC header and a VID header.
      Note: This calculation is applicable only for a NAND Flash which does not support sub-pages. For a NAND Flash supporting sub-pages, the calculation varies with the sub-page size.
    9. In the Filesystem images window, select minimum I/O unit size and press Enter.
    10. Update the minimum I/O unit size to 0x1000 and press Enter. The minimum I/O unit size is equivalent to the NAND Flash device page size.
    11. In the Filesystem images window, select maximum logical eraseblock count and press Enter.
    12. Update the maximum logical eraseblock count to 2048 and press Enter. The maximum logical eraseblock count is the total number of blocks of the NAND Flash device.

    13. Press ESC twice to exit the menu.
  3. Select Exit and press Enter.
    1. Click Yes.