[inet6][tftp] eth_send and friends return zx_status_t

Use a zx_status_t for the return value from eth_send(), udp6_send(),
and icmp6_send(), to help distinguish between failure cases.

Change-Id: I27b7b3224cf2ae5464f8a764dcd0e82f35a4c2aa

[zx] Magenta -> Zircon

The Great Renaming is here!

Change-Id: I3229bdeb2a3d0e40fb4db6fec8ca7d971fbffb94

[libtftp] Allow client settings to override host's

In a WRQ packet, when an option is suffixed with a '!' don't attempt
to override it. This allows us two levels of overrides. For normal
write requests, any overrides set by the server take precendence.
For "forceful" write requests, the server will respect the client's
request. This strategy replaces the previous min/max values behavior.

A client sets its default options with tftp_set_options() and any
"forceful" options in tftp_push_file().

A server sets its overrides with tftp_set_options().

Change-Id: I23267138bfafdeeb0d5ba2054abe83d40e181fff

[bootloader] Force window size on Acers

Force the tftp window size to 8 on "INSYDE Corp." firmware.

Change-Id: Ieff27734eef4742a41c0426b71f50f5ba876111f

[bootloader][bootserver][netsvc] Add file prefix

When bootserver sends files, use a prefix so that they are
not confused with files sent by netcp.

Change-Id: I9623dc822bfdf08b342b4b3c5dd481c7758954a4

[bootloader][netsvc][libtftp] Add timeout support

Add libtftp support for timeout handing as per TFTP RFC. Also,
sets a limit for the number of consecutive timeouts before a
connection is terminated (configurable using
tftp_set_max_timeouts()).

Change-Id: I9a31605d6f926275afdc32fbd8dbcab141ccc993

[bootloader] Fix tftp transfers for small files

Fixes a divide-by-zero error when sending files (or command lines)
< 100 bytes in length.

Change-Id: Icaebba7f7ca1273402756d9f4e9d64fc43307d93

[bootloader] Add tftp support

Allow TFTP connections for transmitting boot files.
Adds an EFI library module type to the make logic, to support
building an EFI version of libtftp.

Change-Id: Iaa2a5efd005b5d1ad52557d9a7759554ad6ebef2

[bootloader] Increase buffer size in advertise()

Related to MG-756.

Change-Id: Ie83289536c9260daab3dcf8f2295fa13fce54d90

[bootloader] Add QUERY (netls) support.

Change-Id: I3bcaa4f05351f03528390200506f41e1d79b37af

[bootserver][gigaboot] complain about non-matching bootloader versions

- pass multiple parameters in the advertising data, including version
- check version and warn if it's not the expected one

Change-Id: Id77b44ec767fdcd4ce6b1c2d82318f8c78962104

[boot] migrate boot data and protocol headers to magenta/boot

This tidies up the top level magenta includes a bit and more
importantly moves multiboot.h somewhere where gigaboot can
find it.

Change-Id: I5c746fdce836e266d207b9bdfac6e940ce9ca294

[bootloader] Unique device id.

- Generate a unique device ID based on the MAC Address and the EFF Short
Diceware word list.
- Display using large font device ID prominently.

Change-Id: I81231aa7ca36084e34ba07c724669528bd9075e8

[bootloader] add nodename to advertisement packet

Defaults to "magenta", unless overridden by magenta.nodename
in the commandline.

Change-Id: If99cdd00d1fd86165530e5de0489e43f4dbcda07

[bootloader] squelch some bootloader spew if needing to retransmit packets

This seems to help if retransmits are needed, since printfing to the
screen can be extremely slow which just causes a cascade of missing
packets.

Change-Id: I1886f34881c630ff760f4ea698737e37af3d12dc

[bootserver][bootloader] Faster netboot

Requires updating bootloader on devices

Change-Id: I084e737d7255348f6cf4bcf7ecf1721c632fd689

[bootloader][bootserver] Add version to advertise message

Introduce version number in advertise message.

Change-Id: I5ea7e10948c23f11ef068a647ac7f80306a86901

[bootloader][bootserver] Dynamic allocation of ramdisk

- Send size of file in NB_FILE message in nbmsg.arg.
- Dynamically allocate ramdisk in bootloader based on the size sent. If
size is 0 (older bootserver) then allocate default (raised to 512MB
though not efficient for smaller ramdisk it will fit the current size of
fuchsia system image).
- Changed progress display of bootserver to show percentage instead of #
per 32kb.
- Tweak payload size to maximize UDP traffic.

Change-Id: I47a95c98061384959006af1248d639b6624a8fcc

[bootloader] Use magenta's netboot.h

Change-Id: Ibbda54d2ca9a402a4a357629f2abd871cacbe8d3

[bootloader] Initial import of gigaboot

Original source:
https://fuchsia.googlesource.com/gigaboot20x6/
Upstream commit:
80eef665f1e248eafe48f9b430fdae702ece20c1

Change-Id: I1be9ad20831e0d790937446febc28755943884a5