Kernel Compile

This guide details how to compile the kernel for Bianbu Linux (using linux-6.6 as an example). Two compilation methods are supported:

• Cross-compilation – faster build time
• Native compilation – more convenient to operate directly on the target system

Download Kernel Source Code

git clone https://gitee.com/bianbu-linux/linux-6.6 ~/linux-6.6

Cross-Compilation Method

Prepare Cross-Development Environment

1. Refer to Bianbu Linux's Development Environment to set up the cross-compiler.

2. Install required build dependencies with:

   sudo apt-get install debhelper libpfm4-dev libtraceevent-dev asciidoc libelf-dev devscripts

Install Cross-Compiler Toolchain

Please visit Toolchain download link: http://archive.spacemit.com/toolchain/

1. Download a toolchain archive, e.g., spacemit-toolchain-linux-glibc-x86_64-v1.0.0.tar.xz:

2. Extract the toolchain with:

   sudo tar -Jxf /path/to/spacemit-toolchain-linux-glibc-x86_64-v1.0.0.tar.xz -C /opt

3. Set the cross-compiler environment variables with:

   export PATH=/opt/spacemit-toolchain-linux-glibc-x86_64-v1.0.0/bin:$PATH

Cross-Compile the Kernel

Enter the kernel source directory:

cd ~/linux-6.6

Set kernel compilation parameters:

export CROSS_COMPILE=riscv64-unknown-linux-gnu-
export ARCH=riscv
export LOCALVERSION=""

Generate the default configuration:

make k1_defconfig

If you need to build the PREEMPT_RT real-time kernel for the bl-v2.0.y branch, first update the source tree to commit 3ac79a6dd update rt defconfig or any later version. Then apply the RT patch and generate the configuration. If not required, you can skip this step:

patch -p1 < rt-linux/*.patch
make k1_rt_defconfig

Modify the configuration if needed; otherwise, you may skip this step:

make menuconfig

Save the modified configuration:

make savedefconfig
mv defconfig arch/riscv/configs/k1_defconfig

Compile the Debian package:

make -j$(nproc) bindeb-pkg

If you see the following messages, the build has completed successfully.

dpkg-genchanges: info: binary-only upload (no source code included)
 dpkg-source --after-build .
dpkg-buildpackage: info: binary-only upload (no source included)

The resulting .deb packages are located in the parent directory. The key packages are:

• linux-image-6.6.36_6.6.36-*.deb - Kernel Image package.

• linux-tools-6.6.36_6.6.36-*.deb - perf and other tool packages.

Copy the packages to the device, install, and then reboot:

sudo dpkg -i linux-image-6.6.36_6.6.36-*.deb
sudo reboot

Cross Compile Modules

To compile out-of-tree kernel modules, rtl8852bs is the example below, run the command as:

cd /path/to/rtl8852bs
make -j$(nproc) -C ~/linux-6.6 M=/path/to/rtl8852bs modules

• Replace /path/to/rtl8852bs with actual module path

Clean command:

make -j$(nproc) -C ~/linux-6.6 M=/path/to/rtl8852bs clean

Cross Compile Device Tree

To compile the device tree separately:

make -j$(nproc) dtbs

Native Compilation

You can directly compile the kernel on Bianbu, here is the guide.

Local Development Environment

Install the dependencies:

sudo apt-get install flex bison libncurses-dev debhelper libssl-dev u-boot-tools libpfm4-dev libtraceevent-dev asciidoc bc rsync libelf-dev devscripts

Native Compile Kernel

Navigate to the kernel source directory:

cd ~/linux-6.6

Set kernel compilation parameters:

export ARCH=riscv
export LOCALVERSION=""

Generate default configuration:

make k1_defconfig

Modify the configuration if needed; otherwise, you may skip this step:

make menuconfig

To save the modified configuration:

make savedefconfig
mv defconfig arch/riscv/configs/k1_defconfig

Compile the Debian package:

make -j$(nproc) bindeb-pkg

If you see the following messages, the build has completed successfully.

dpkg-genchanges: info: binary-only upload (no source code included)
 dpkg-source --after-build .
dpkg-buildpackage: info: binary-only upload (no source included)

The resulting .deb packages are located in the parent directory. The key packages are:

• linux-image-6.6.36_6.6.36-*.deb - Kernel Image package.

• linux-tools-6.6.36_6.6.36-*.deb - perf and other tool packages.

Install and then reboot:

sudo dpkg -i linux-image-6.6.36_6.6.36-*.deb
sudo reboot

Native Module Compilation

To compile out-of-tree kernel modules locally, you can do it without relying on the kernel source.

First, install linux-headers:

sudo apt-get install linux-headers-`uname -r`

Then compile the module, for example rtl8852bs:

cd /path/to/rtl8852bs
make -j$(nproc) -C /lib/modules/`uname -r`/build M=/path/to/rtl8852bs modules

• Replace /path/to/rtl8852bs with your actual module path

Clean command:

make -j$(nproc) -C /lib/modules/`uname -r`/build M=/path/to/rtl8852bs clean

Build Other Components

u-boot

Download the source code:

git clone https://gitee.com/bianbu-linux/uboot-2022.10 ~/uboot-2022.10

For cross-compilation, configure the following parameters first. Skip for native compilation:

export PATH=/opt/spacemit-toolchain-linux-glibc-x86_64-v1.0.0/bin:$PATH
export CROSS_COMPILE=riscv64-unknown-linux-gnu-
export ARCH=riscv

Compile the Debian package:

cd ~/uboot-2022.10
VERSION=1~`git rev-parse --short HEAD`
dch --create --package u-boot-spacemit -v ${VERSION} --distribution mantic-porting --force-distribution 'Bianbu Test'
dpkg-buildpackage -us -uc -b

The generated Debian package is located in the parent directory. Install it with dpkg and reboot to take effect.

opensbi

Download the source code:

git clone https://gitee.com/bianbu-linux/opensbi ~/opensbi

For cross-compilation, configure the following parameters first. Skip for native compilation:

export PATH=/opt/spacemit-toolchain-linux-glibc-x86_64-v1.0.0/bin:$PATH
export CROSS_COMPILE=riscv64-unknown-linux-gnu-

Compile the Debian package:

cd ~/opensbi
VERSION=1~`git rev-parse --short HEAD`
dch --create --package opensbi-spacemit -v ${VERSION} --distribution mantic-porting --force-distribution 'Bianbu Test'
dpkg-buildpackage -us -uc -b

The generated Debian package is located in the parent directory. Install it with dpkg and reboot to take effect.