add devp2p page, update devguide + mobile

content/docs/developers/dapp-developer/mobile.md

@@ -336,11 +336,6 @@ let tx    = GethNewTransaction(1, to, GethNewBigInt(0), GethNewBigInt(0), GethNe
 let chain = GethNewBigInt(1) // Chain identifier of the main net
 ```
 
-*Although Swift usually rewrites `NSError` returns to throws, this particular
-instance seems to have been missed for some reason (possibly due to it being a
-constructor). It will be fixed in a later version of the iOS bindings when the appropriate
-fixes are implemented upstream in the `gomobile` project.*
-
 The transaction `tx` can now be signed using the authorization methods described above:
 
 ```swift

content/docs/developers/geth-developer/devguide.md

@@ -1,5 +1,5 @@
 ---
-title: Developer Guide
+title: Getting Started
 sort_key: A
 ---
 
@@ -8,7 +8,7 @@ Developers are people who are interested to build, develop, debug, submit
 a bug report or pull request or otherwise contribute to the Geth source code.
 
 Please see [Contributing](/content/docs/developers/contributing.md) for the
-GHeth contribution guidelines.
+Geth contribution guidelines.
 
 ## Building and Testing
 
@@ -60,9 +60,9 @@ go test -v -bench . -run BenchmarkJoin
 
 For more information, see the [go test flags][testflag] documentation.
 
-### Getting Stack Traces
+### Stack Traces
 
-If `geth` is started with the `--pprof` option, a debugging HTTP server is made available
+If Geth is started with the `--pprof` option, a debugging HTTP server is made available
 on port 6060. Navigating to <http://localhost:6060/debug/pprof> displays the heap,
 running routines etc. By clicking "full goroutine stack dump" a trace can be generated
 that is useful for debugging.

content/docs/tools/devp2p/index.md

@@ -0,0 +1,171 @@
+---
+title: devp2p
+---
+
+[DevP2P](https://github.com/ethereum/devp2p) is a set of network protocols that form the 
+Ethereum peer-to-peer network. The DevP2P specifications define precisely how nodes
+should find each other and communicate. Geth implements the DevP2P specifications in Go.
+
+The DevP2P stack includes the low-level peer-to-peer protocols that define discovery and
+secure sessions between nodes such as:
+
+[Ethereum Node Records](https://github.com/ethereum/devp2p/blob/master/enr.md): A standard format for connectivity information for a node
+[Discovery protocol](https://github.com/ethereum/devp2p/blob/master/discv4.md): Defines how nodes find each other.
+[RLPx protocol](https://github.com/ethereum/devp2p/blob/master/rlpx.md): Defines a TCP based transport system for communication between nodes.
+
+DevP2P also includes the RLPx-based application level protocols including: 
+
+[Ethereum Wire Protocol](https://github.com/ethereum/devp2p/blob/master/caps/eth.md): facilitates exchange of blockchain data between peers
+[Ethereum Snapshot Protocol](https://github.com/ethereum/devp2p/blob/master/caps/snap.md): enables exchange of snapshots between peers
+[Light Ethereum Subprotocol](https://github.com/ethereum/devp2p/blob/master/caps/les.md): protocol used by light clients
+
+To debug and develop these networking components, Geth includes a command line tool called `devp2p`.
+
+This page will outline some of `devp2p`s built-in tools.
+
+### ENR Decoding
+
+Ethereum Node Records can be decoded, verified and displayed to the terminal using `enrdump`. It takes the ENR in its encoded form, which
+is the base64 encoding of its RLP representation. A decoded human-readable text representation is displayed.
+
+Use `devp2p enrdump <base64>` to verify and display an Ethereum Node Record.
+
+Read more on [Ethereum Node Records](https://ethereum.org/en/developers/docs/networking-layer/network-addresses/#enr) or browse the [specs](https://github.com/ethereum/devp2p/blob/591edbd36eb57280384d07373a818c00bddf3b31/enr.md).
+
+### Node Key Management
+
+The `devp2p key ...` command family deals with node key files.
+
+Run `devp2p key generate mynode.key` to create a new node key in the `mynode.key` file.
+
+Run `devp2p key to-enode mynode.key -ip 127.0.0.1 -tcp 30303` to create an enode:// URL
+corresponding to the given node key and address information.
+
+### Maintaining DNS Discovery Node Lists
+
+The devp2p command can create and publish DNS discovery node lists.
+
+Run `devp2p dns sign <directory>` to update the signature of a DNS discovery tree.
+
+Run `devp2p dns sync <enrtree-URL>` to download a complete DNS discovery tree.
+
+Run `devp2p dns to-cloudflare <directory>` to publish a tree to CloudFlare DNS.
+
+Run `devp2p dns to-route53 <directory>` to publish a tree to Amazon Route53.
+
+More information about these commands can be found in the [DNS Discovery Setup Guide][dns-tutorial].
+
+### Node Set Utilities
+
+There are several commands for working with JSON node set files. These files are generated
+by the discovery crawlers and DNS client commands. Node sets also used as the input of the
+DNS deployer commands.
+
+Run `devp2p nodeset info <nodes.json>` to display statistics of a node set.
+
+Run `devp2p nodeset filter <nodes.json> <filter flags...>` to write a new, filtered node
+set to standard output. The following filters are supported:
+
+- `-limit <N>` limits the output set to N entries, taking the top N nodes by score
+- `-ip <CIDR>` filters nodes by IP subnet
+- `-min-age <duration>` filters nodes by 'first seen' time
+- `-eth-network <mainnet/rinkeby/goerli/ropsten>` filters nodes by "eth" ENR entry
+- `-les-server` filters nodes by LES server support
+- `-snap` filters nodes by snap protocol support
+
+For example, given a node set in `nodes.json`, you could create a filtered set containing
+up to 20 eth mainnet nodes which also support snap sync using this command:
+
+```sh
+devp2p nodeset filter nodes.json -eth-network mainnet -snap -limit 20
+```
+
+### Discovery v4 Utilities
+
+The `devp2p discv4 ...` command family deals with the [Node Discovery v4][discv4]
+protocol.
+
+Run `devp2p discv4 ping <enode/ENR>` to ping a node.
+
+Run `devp2p discv4 resolve <enode/ENR>` to find the most recent node record of a node in
+the DHT.
+
+Run `devp2p discv4 crawl <nodes.json path>` to create or update a JSON node set.
+
+### Discovery v5 Utilities
+
+The `devp2p discv5 ...` command family deals with the [Node Discovery v5][discv5]
+protocol. This protocol is currently under active development.
+
+Run `devp2p discv5 ping <ENR>` to ping a node.
+
+Run `devp2p discv5 resolve <ENR>` to find the most recent node record of a node in
+the discv5 DHT.
+
+Run `devp2p discv5 listen` to run a Discovery v5 node.
+
+Run `devp2p discv5 crawl <nodes.json path>` to create or update a JSON node set containing
+discv5 nodes.
+
+### Discovery Test Suites
+
+The devp2p command also contains interactive test suites for Discovery v4 and Discovery
+v5. To run these tests a networking environment must be set up with two separate UDP listening 
+addresses are available on the same machine. The two listening addresses must also be routed such 
+that they are able to reach the node you want to test.
+
+For example, to run the test on the local host when the node under test is
+also on the local host, assign two IP addresses (or a larger range) to the
+loopback interface. On macOS, this can be done by executing the following command:
+
+```sh
+sudo ifconfig lo0 add 127.0.0.2
+```
+
+Either test suite can then be run as follows: 
+
+1. Start the node under test first, ensuring that it won't talk to the Internet (i.e. disable bootstrapping). An easy way to prevent
+unintended connections to the global DHT is listening on `127.0.0.1`.
+
+2. Get the ENR of the node and store it in the `NODE` environment variable.
+
+3. Start the test by running `devp2p discv5 test -listen1 127.0.0.1 -listen2 127.0.0.2 $NODE`.
+
+### Eth Protocol Test Suite
+
+The Eth Protocol test suite is a conformance test suite for the [eth protocol][eth].
+
+To run the eth protocol test suite, the node needs to be initialized as follows:
+
+1. initialize the geth node with the `genesis.json` file contained in the `testdata` directory
+   
+2. import the `halfchain.rlp` file in the `testdata` directory
+   
+3. run geth with the following flags:
+
+```sh
+geth --datadir <datadir> --nodiscover --nat=none --networkid 19763 --verbosity 5
+```
+
+Then, run the following command, replacing `<enode>` with the enode of the geth node:
+
+```sh
+devp2p rlpx eth-test <enode> cmd/devp2p/internal/ethtest/testdata/chain.rlp cmd/devp2p/internal/ethtest/testdata/genesis.json
+```
+
+Repeat the above process (re-initialising the node) in order to run the Eth Protocol test suite again.
+
+#### Eth66 Test Suite
+
+The Eth66 test suite is also a conformance test suite for the eth 66 protocol version specifically.
+To run the eth66 protocol test suite, initialize a geth node as described above and run the following command,
+replacing `<enode>` with the enode of the geth node:
+
+```sh
+devp2p rlpx eth66-test <enode> cmd/devp2p/internal/ethtest/testdata/chain.rlp cmd/devp2p/internal/ethtest/testdata/genesis.json
+```
+
+[eth]: https://github.com/ethereum/devp2p/blob/master/caps/eth.md
+[dns-tutorial]: https://geth.ethereum.org/docs/developers/dns-discovery-setup
+[discv4]: https://github.com/ethereum/devp2p/tree/master/discv4.md
+[discv5]: https://github.com/ethereum/devp2p/tree/master/discv5/discv5.md