[tables] Redefine methods for accessing linker tables
Intel's C compiler (icc) chokes on the zero-length arrays that we
currently use as part of the mechanism for accessing linker table
entries. Abstract away the zero-length arrays, to make a port to icc
easier.
Introduce macros such as for_each_table_entry() to simplify the common
case of iterating over all entries in a linker table.
Represent table names as #defined string constants rather than
unquoted literals; this avoids visual confusion between table names
and C variable or type names, and also allows us to force a
compilation error in the event of incorrect table names.
[cmdline] Add setting expansion using ${...} syntax
Allow settings to be expanded in arbitrary commands, such as
kernel http://10.0.0.1/boot.php?uuid=${uuid}
Also add the "echo" command, as being the easiest way to test this
features.
Add "name" field to struct device to allow human-readable hardware device
names.
Add "dev" pointer in struct net_device to tie network interfaces back to a
hardware device.
Force natural alignment of data types in __table() macros. This seems to
prevent gcc from taking the unilateral decision to occasionally increase
their alignment (which screws up the table packing).
Michael Brown