Update hijack boot

Author: ThomasFarstrike

docs/os-development/hijack-boot.md

@@ -2,6 +2,11 @@
 
 You can intercept the boot sequence to drop into a raw REPL shell instead of starting MicroPythonOS — useful for debugging, running custom startup code, or recovering from a broken install.
 
+## How to Hijack the Boot Sequence
+
+Basically, you have to create a file /lib/mpos/main.py
+Any code you place there, will be executed by the built-in main.py
+
 ## The one-liner
 
 ```python
@@ -12,7 +17,9 @@ Copy-paste this into your device's REPL (e.g. over serial) and hit enter. The `o
 
 ## What it does
 
-`/lib/mpos/main.py` is MicroPythonOS's entry point. When the firmware boots, it looks for `main.py` on the filesystem — if found, it runs it first. This one-liner writes a stub that raises an error instead, which means:
+`/lib/mpos/main.py` is MicroPythonOS's entry point, imported by the frozen `internal_filesystem/main.py`.
+
+When the firmware boots, it looks for `main.py` on the filesystem — if found, it runs it first. This one-liner writes a stub that raises an error instead, which means:
 
 1. The device boots into a clean MicroPython REPL.
 2. No MicroPythonOS code (LVGL, apps, frameworks) is loaded.
@@ -34,4 +41,6 @@ To restore normal boot on every power-on, delete the stub:
 
 ```python
 __import__("os").remove("/lib/mpos/main.py")
+import shutil
+shutil.rmtree("/lib/mpos")
 ```

mkdocs.yml

@@ -91,10 +91,10 @@ nav:
       - On MacOS: os-development/macos.md
       - On Windows: os-development/windows.md
       - Installing on ESP32: os-development/installing-on-esp32.md
-      - Hijacking the Boot: os-development/hijack-boot.md
       - Automated Testing: os-development/automated-testing.md
       - Emulated ESP32: os-development/emulating-esp32-on-desktop.md
       - Porting Guide: os-development/porting-guide.md
+      - Hijacking the Boot: os-development/hijack-boot.md
   - Web Port:
       - Using the Web Port: web-port/using.md
       - Developer Info: web-port/developer.md