Update 'IDEs Support' section in README

README.md

@@ -678,15 +678,46 @@ Now we can proceed as with Spike, debugging works in a similar way:
 
 Further information about GDB debugging is available [here](https://sourceware.org/gdb/onlinedocs/gdb/) and [here](https://sourceware.org/gdb/onlinedocs/gdb/Remote-Debugging.html#Remote-Debugging).
 
-## <a name="ide"></a> Building Rocket Chip with an IDE
+## <a name="ide"></a> IDEs Support
 
 The Rocket Chip Scala build uses [mill](https://github.com/com-lihaoyi/mill) as build tool.
-IDEs like [IntelliJ](https://www.jetbrains.com/idea/) and [VSCode](https://code.visualstudio.com/)
-are popular in the Scala community and work with Rocket Chip. Use:
-```
-mill mill.bsp.BSP/install
-```
-to use one of these IDEs, there is one minor peculiarity of the Rocket Chip build that must be addressed.
+
+IDEs like [IntelliJ](https://www.jetbrains.com/idea/) and [VSCode](https://code.visualstudio.com/) are popular in the Scala community and work with Rocket Chip.
+
+The Rocket Chip currently uses `nix` to configure the build and/or development environment, you need to install it first depending on your OS distro.
+
+Then follow the steps:
+
+1. Generate BSP config by running:
+
+   ```
+   mill mill.bsp.BSP/install
+   ```
+
+2. Patch the `argv` in `.bsp/mill-bsp.json`, from
+
+   ```json
+   {"name":"mill-bsp","argv":["/usr/bin/mill","--bsp","--disable-ticker","--color","false","--jobs","1"],"millVersion":"0.10.9","bspVersion":"2.0.0","languages":["scala","java"]}
+   ```
+
+   to
+
+   ```json
+   {"name":"mill-bsp","argv":["/usr/bin/nix","develop","-c","mill","--bsp","--disable-ticker","--color","false","--jobs","1"],"millVersion":"0.10.9","bspVersion":"2.0.0","languages":["scala","java"]}
+   ```
+
+### For IntelliJ users
+
+3. Install and configure [Scala](https://plugins.jetbrains.com/plugin/1347-scala) plugin.
+
+4. BSP should be automatically run.
+   If it doesn't, click `bsp` on the right bar, then right-click on your project to reload.
+
+### For VSCode users
+
+3. Install and configure [Metals](https://marketplace.visualstudio.com/items?itemName=scalameta.metals) extension.
+
+4. Execute VSCode command `Metals: Import build`.
 
 ## <a name="contributors"></a> Contributors