Portability is a big issue for this document.

Debian 2.2 ships with perl 5.0 patchlevel 5 subversion 3.
This version does not support:
+ use constant
+ [:xdigit:]

On FreeBSD/alpha the ELF base address is a 64-bit address above 4GB.
At least one such machine runs a perl with 32-bit integer arithmetic.
Thus we must handle the value as a string, not a number.

Hexadecimal values are output without leading '0x' to enable
echo "ibase=16; ELF_BASE" | bc
