How to upgrade Brainux to Debian 12:

How to Upgrade Brainux to Debian 12

1: Mount the microSD card in VirtualBox

First, make the host recognize the SD card as a block device and pass it to the virtual machine.

(For Linux or macOS hosts)

1. Insert the microSD card into the PC.

2. Check the device name using:

code:check_device

lsblk

3. Register the SD card as a “raw disk” in VirtualBox.

Example (Linux host):

code:linux

VBoxManage internalcommands createrawvmdk -filename ~/sdcard.vmdk -rawdisk /dev/sdX

Example (Windows host):

code:powershell

VBoxManage internalcommands createrawvmdk -filename "C:\Users\YourName\sdcard.vmdk" -rawdisk \\.\PhysicalDriveX

4. Add the created VMDK file to the VM’s storage:

Open VirtualBox Manager

Go to VM Settings → Storage → Add Existing Disk

⚠️ Note:

Requires administrator/root privileges.

Be very careful: misconfiguration can destroy the SD card contents on the host.

Method 2: Use a USB card reader (safer & recommended)

1. Insert the microSD into a USB card reader.

2. In VirtualBox Manager → VM Settings → USB, add a USB device filter for the card reader.

3. Start the VM.

→ The guest OS will directly recognize the microSD as a USB device.

This avoids raw-disk access and is safer.

2: Mount the rootfs and chroot into it

1. Create a mount folder:

code:create mount folder

sudo mkdir /mnt/rootfs

2. Find the rootfs partition on the microSD:

code:check sdcard

lsblk

3. Mount it:

code:mount rootfs

sudo mount /dev/sdb2 /mnt/rootfs

4. Enter the chroot:

code:enter_chroot

sudo chroot /mnt/rootfs /bin/bash

Edit the sources list:

code:edit_sources

sudo nano /etc/apt/sources.list

Replace with the following repositories:

code:sources.list

# --- Debian 12 (Bookworm) Official Repositories ---

# --- Debian 12 Bookworm backports ---

# --- Archive (for older packages) ---

You need to disable validity checks:

code:disable_check

echo 'Acquire::Check-Valid-Until "false";' | sudo tee /etc/apt/apt.conf.d/99ignore-valid-until

4: Perform the Upgrade

code:upgrade

sudo apt update

sudo apt upgrade

sudo apt full-upgrade

Exit the chroot once. Then re-enter and confirm the upgrade with:

code:check_version

lsb_release -a

If it shows bookworm, the upgrade was successful.

5: Clean up old packages

Finally, remove unnecessary packages:

code:remove

sudo apt --purge autoremove

✅ Done — your Brainux system should now be upgraded to Debian 12 (Bookworm).