e is one special section, the '.MMIX.reg_contents' section.
Contents in this section is assumed to correspond to that of global
registers, and symbols referring to it are translated to special
symbols, equal to registers.  In a final link, the start address of the
'.MMIX.reg_contents' section corresponds to the first allocated global
register multiplied by 8.  Register '$255' is not included in this
section; it is always set to the program entry, which is at the symbol
'Main' for 'mmo' files.

   Global symbols with the prefix '__.MMIX.start.', for example
'__.MMIX.start..text' and '__.MMIX.start..data' are special.  The
default linker script uses these to set the default start address of a
section.

   Initial and trailing multiples of zero-valued 32-bit words in a
section, are left out from an mmo file.