Raspberry Pi

We support the following platforms:

• QEMU
• Raspberry Pi model B rev 2.0

Running on QEMU

In order to emulate the Raspberry Pi on QEMU you need a patched version of the emulator that supports the RPi machine. This patched version has been developed by Torlus and can be downloaded and installed with the following commands:

    git clone -b rpi https://github.com/embox/qemu.git
    cd qemu
    git submodule update --init pixman
    ./configure --target-list=arm-softmmu --disable-werror 
    make

Of course, you are free to use configure options to install QEMU wherever you want in your filesystem. PS you can use git submodule update --init dtc for some reason

More information on the patched version of QEMU for emulating RPi can be found at the following links:

• QEMU patches for RPi emulation - Initial release
• QEMU branches - rpi (Raspberry Pi) - firebee
• Raspberry Pi Bare Bones - Testing your operating system (QEMU)

Building Embox for QEMU

There is a special configuration template for Raspberry Pi. So first of all, preload it with:

    make confload-platform/raspberry_pi/rpi1-qemu

After that build the kernel using the following command:

    make

Running Embox on QEMU

Once you have built the kernel you are ready to run it on QEMU. Just type on the command line:

    <qemu-built-dir>/arm-softmmu/qemu-system-arm -kernel build/base/bin/embox  -M raspi -m 256 -no-reboot -serial stdio

Running on Raspberry Pi Model B rev 2.0 (Rpi1)

1. We will use a micro SD card to boot, so let's get the bootloader first.

   • Download Raspbian Lite here https://downloads.raspberrypi.org/raspbian_lite_latest. It is useful because you then can choose what to boot - Linux or Embox.
   • Install to SD card - dd bs=4M if=2020-02-13-raspbian-buster-lite.img of=/dev/sdX conv=fsync. More information about how to write the image to your SD card is available here.

2. Compile Embox.

   make confload-platform/raspberry_pi/rpi1-model-b
   

   And build the kernel using the following command:

   make
   

3. To boot Embox just copy the binary to SD card:

   • Mount SD boot partition - sudo mount /dev/sdX1 /mnt (so if your SD card is /dev/sdb then it should be sudo mount /dev/sdb1 /mnt)
   • Copy Embox kernel sudo cp build/base/bin/embox.bin /mnt/kernel.img
   • Umount SD card sudo umount /mnt

   Or like a script:

   #!/bin/sh
   set -xe
   RPI_BOOT=/dev/sdb1
   sudo mount $RPI_BOOT /mnt
   sudo cp build/base/bin/embox.bin /mnt/kernel.img
   sudo umount /mnt
   

4. Now you can insert SD card to your board and power on. Embox will be loaded and fb_direct_access command will paint the rectangle on the screen.

UART (optional)

To see Embox output on the serial port you have to connect UART-to-USB adapter to the board first. We use RDC1-USB-UART adapter.

You can find pinout here - https://elinux.org/RPi_Low-level_peripherals#P1_Header. Let's power the adapter from usb, and power RaPi from the adapter then. Connect the adapter pins:

RDC1      Rapi

GND <---> GND
5V  <---> 5V
RX  <---> TXD0/GPIO14
TX  <---> RXD0/GPIO15

Now you can plug your USB cable into RDC1 adapter and then plug in into your PC.

Connect using minicom:

sudo minicom -d /dev/ttyUSB0

You will see Embox output:

Embox kernel start
        unit: initializing embox.kernel.task.task_resource: done
        unit: initializing embox.kernel.task.task_table: done
 ***
Default IO device[ttyS0]
>export PWD=/
>export HOME=/
>fb_direct_access
>tish
root@embox:/#

Useful information Building an Operating System for the Raspberry Pi