The NetBook BootStrap Process

Here are some notes on the booting process of the NetBook with regard to being able to boot operating systems other than EPOC.


Types of BootStraps

As there is no actual hard power off mode (other than removing both the main and backup batteries), the NetBook has a number of different bootstrap modes depending upon the state of the NetBook.

  1. Cold BootLoad

    After a "hard" power cycle (both batteries removed), there is nothing left in the DRAM of the NetBook and the Loader (located on the FLASH/DRAM module) has to load an "EPOC ARM ROM" format image.

    Two methods of getting the binary boot image:

    1. Serial Bootstrap
      This is simply a YMODEM transfer of a binary image with the serial settings of 115200 baud, no parity, 8 data bits and 1 stop bit. The unix "sb" command works fine as does a copy of the old DOS telix program. Note that even at 115200, it takes about half a hour to upload the default 12 Mbyte EPOC 5 image.

    2. CF Bootstrap
      Loads a file os.img from a FAT formatted CF card. This is much faster (about 20 sec. vs 30 min.) way to boot large images. The FAT compnetatability seems quite good as reads cards formatted and written from the NetBook itself, my Kodak DC265 Camera, IBM PCDOS 7, Linux mtools and Linux fatfs.

    LCD Control/Status Registers Zeroed () 0x100 header dumped 0xc8000000

  2. Cold Boot With a valid EPOC image in memory,
    1. Press Reset Button.
    2. Hold down both Keys and turn the power on.
    Effects: loses the current time

  3. Warm Boot
    1. Press Reset Button.
    2. Turn the power on.

Craig Newell, 14 Dec. 1999