doc: Update CHANGELOG

Author: fischeti

CHANGELOG.md

@@ -4,6 +4,19 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Added
+
+- Support for source-based routing algorithm in routers, chimnyes and `floogen`. The route is encoded in the header as a `route_t` field, and each router consumes a couple of bits to determine the output ports. In the chimney, a two-stage encoder was added to first determine the destination ID of the request, and then retrive the pre-computed route to that destination from a table. The `floogen` configuration was extended to support the new routing algorithm, and it will also generate the necessary tables for the chimneys.
+
+### Changed
+
+- `floo_route_comp` now supports source-based routing, and can output both destination ID and a route to the destination.
+- The chimneys have an additional port `route_table_i` to receive the pre-computed routing table that is generated by `floogen`.
+- System address map was renamed from `AddrMap` to `Sam`.
+- The destination field in the flit header have a new type `dst_t` which is either set to `route_t` for the new source-based routing algorithm, and `id_t` for all the other routing algorithms.
+
 ## [0.4.0] - 2024-02-07
 
 ### Added