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(multiboot.info)Header address fields

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The address fields of Multiboot header
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   All of the address fields enabled by flag bit 16 are physical
addresses.  The meaning of each is as follows:

`header_addr'
     Contains the address corresponding to the beginning of the
     Multiboot header -- the physical memory location at which the
     magic value is supposed to be loaded. This field serves to
     "synchronize" the mapping between OS image offsets and physical
     memory addresses.

`load_addr'
     Contains the physical address of the beginning of the text
     segment. The offset in the OS image file at which to start loading
     is defined by the offset at which the header was found, minus
     (header_addr - load_addr). load_addr must be less than or equal to
     header_addr.

`load_end_addr'
     Contains the physical address of the end of the data segment.
     (load_end_addr - load_addr) specifies how much data to load.  This
     implies that the text and data segments must be consecutive in the
     OS image; this is true for existing a.out executable formats.

`bss_end_addr'
     Contains the physical address of the end of the bss segment. The
     boot loader initializes this area to zero, and reserves the memory
     it occupies to avoid placing boot modules and other data relevant
     to the operating system in that area.

`entry_addr'
     The physical address to which the boot loader should jump in order
     to start running the operating system.