rpi4-os

Build Instructions

This project uses a sh to automate the build process and generate the kernel8.img file. Follow the steps below to successfully compile the project:

Prerequisites

1. GCC Toolchain: The Makefile uses the aarch64-elf cross-compiler. Ensure that this toolchain is installed.

   • You can download the toolchain from the official Arm website.

2. ARMGNU Variable: The Makefile defines the cross-compiler prefix with the ARMGNU variable. If your toolchain has a different prefix, adjust the ARMGNU variable in the Makefile:

   ARMGNU ?= aarch64-elf

By following these steps and adjusting the Makefile variables and paths as necessary, you should be able to compile and build your project successfully.

Build Command

To build the project, run the following command:

./build.sh

UART Setup for Raspberry Pi 4

To enable UART communication on your Raspberry Pi 4, follow these steps to correctly connect the TTL-to-USB adapter to the Pi’s GPIO pins.

1. Pin Connections:

Use the following GPIO pins on the Raspberry Pi 4 for UART:

• TX (Transmit): GPIO 14 (Pin 8)
• RX (Receive): GPIO 15 (Pin 10)
• GND (Ground): Pin 6

Now, connect the TTL-to-USB adapter cables as follows:

• Adapter TX (usually an green wire) → Raspberry Pi RX (GPIO 15, Pin 10)
• Adapter RX (usually a white wire) → Raspberry Pi TX (GPIO 14, Pin 8)
• Adapter GND (usually a black wire) → Raspberry Pi GND (Pin 6)

2. Enable UART on the Raspberry Pi 4:

To enable UART on the Pi, follow these steps:

1. Edit the config.txt file on the sd card:

2. Add the following lines to enable UART:

   enable_uart=1
   enable_gic=1
   hdmi_group=1
   hdmi_mode=16
   core_freq_min=500

3. Use a Terminal Application:

Once connected, you can use a terminal application (like Putty on Windows or minicom on Linux) to interface with the Raspberry Pi via the UART connection. Ensure you set the baud rate to 115200.