12

Next: Load optional RAM file system (initrd)   Previous: Prepare parameters for OS loading   Contents: Index


Loads OS Image

After the bootloadr knows what OS Image (Kernel) to load, it loads the Image to RAM This usually must be done to a specific address the specific address is either hard coded into the bootloader or is read from the kernel image file.

The bootloader needs to be able to read and understand the object format of the OS kernel. It will extract the actual memory image from the object file and place it to memory according to the header of the object format and then jump to the entry point (also given in the object header).

In case of Linux which uses MMU the base address is usually virtual address and the bootloader needs to translate it to physical address, this is why we usually can't load linux using a bootloader written for other OS's that don't use MMU such as vxWorks.


Next:
Previous:
Contents:
Load optional RAM file system (initrd)
Prepare parameters for OS loading
Index
Prepared by Ori Idan Helicon technologies