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Elf OS 4.1.0 Secondary Boot Loader Procedure

Pre-requisite:  Upgrade to the latest version of Kernel 4.1.0 and install the basetools40.lbr file to update all the commands.  

Warning: Do not try this with earlier versions of the kernel.  Use the ver command to verify the latest version of the kernel is installed before proceeding.


 1) Run the version command with no parameters to verify that kernel version 348 or higher is installed.

   a) ver 

   b)  You should see this output:


       : ver

      4.1.0 Build 348 8/23/2021


c) If the Build number is less than 348,  Stop and install the latest kernel version before proceeding.


2) Create an os directory underneath root.

  a) chdir /

  b) mkdir os


3) Change into the /os directory and create a kernel file

  a)  chdir /os

   b) kread kernel


4) Check the /os directory and verify that the kernel file was created.  Stop if there is no /os/kernel file!  Redo the above instructions.

  a) chdir /os

  b) dir



5) Change into the /bin directory and install the secondary boot program.

  a) chdir /bin

  b) sys boot2.bin


6) The system should now install the new boot loader, and reboot using the kernel file in /os/kernel.

  a) In the future, for any new kernel updates you should copy the new kernel file over /os/kernel rather than using the sys command.


Optional steps:

A) You can hide the /os directory if you wish.

  1) chdir /

  2) chmod +h os


B) You can use setboot2 to only load two sectors when booting.  This makes boot up slightly faster.

  1) setboot2


C) If you wish to undo setboot2 and load all sectors when booting, run the setboot command.

  1) setboot


SUGGESTION : Keep copies of  your previous versions of Elf-OS kernels in /os

If a new kernel has an issue, you can use sedit to rename the kernel names in the /os directory so that the older kernel name becomes kernel again.