Source

This document introduces the development environment, download, and compilation methods for the SDK source code.

Development Environment

Hardware Configuration

Recommended configuration:

• CPU: 12th Gen Intel(R) Core(TM) i5 or above
• Memory: 16GB or above
• Disk: SSD, 256GB or above

Operating System

Recommended Ubuntu 20.04 or newer LTS version, other Linux distributions have not been tested.

Install Dependencies

Ubuntu 16.04 and 18.04:

sudo apt-get install git build-essential cpio unzip rsync file bc wget python3 libncurses5-dev libssl-dev dosfstools mtools u-boot-tools flex bison python3-pip
sudo pip3 install pyyaml

Ubuntu 20.04 or higher:

sudo apt-get install git build-essential cpio unzip rsync file bc wget python3 python-is-python3 libncurses5-dev libssl-dev dosfstools mtools u-boot-tools flex bison python3-pip
sudo pip3 install pyyaml

Download

Use repo (version >= 2.41) to download the complete SDK. If you don't have repo, refer to Git Repo Mirror Usage Help for installation.

Bianbu Linux code is hosted on Gitee. Before downloading, refer to this document to set up SSH Keys.

To download the code, for example, to download the bl-v1.0.y branch:

mkdir ~/bianbu-linux
cd ~/bianbu-linux
repo init -u git@gitee.com:bianbu-linux/manifests.git -b main -m bl-v1.0.y.xml
repo sync
repo start bl-v1.0.y --all

Or to download the bl-v2.0.y branch:

mkdir ~/bianbu-linux-2.0
cd ~/bianbu-linux-2.0
repo init -u git@gitee.com:bianbu-linux/manifests.git -b main -m bl-v2.0.y.xml
repo sync
repo start bl-v2.0.y --all

It is recommended to download the third-party software packages required by buildroot in advance and distribute them within the team to avoid network congestion on the main server.

wget -c -r -nv -np -nH -R "index.html*" http://archive.spacemit.com/buildroot/dl

Directory structure

├── bsp-src               # Stores linux kernel、uboot、opensbi source
│   ├── linux-6.1
│   ├── linux-6.6
│   ├── opensbi
│   └── uboot-2022.10
├── buildroot             # buildroot main directory
├── buildroot-ext         # Custom extensions, including board, configs, package, patches subdirectories
├── Makefile              # Top-level Makefile
├── package-src           # Directory for locally expanded application or library source code
│   ├── ai-support
│   ├── drm-test
│   ├── img-gpu-powervr
│   ├── k1x-cam
│   ├── k1x-jpu
│   ├── k1x-vpu-firmware
│   ├── k1x-vpu-test
│   ├── mesa3d
│   ├── mpp
│   └── v2d-test
└── scripts               # Scripts used for compilation

Cross Compilation

First Complete Compilation

For the first compilation, it is recommended to use make envconfig for a complete build.

If you have modified buildroot-ext/configs/spacemit_<solution>_defconfig, use make envconfig to compile.

In other cases, use make to compile.

cd ~/bianbu-linux
make envconfig
Available configs in buildroot-ext/configs/:
  1. spacemit_k1_defconfig
  2. spacemit_k1_minimal_defconfig
  3. spacemit_k1_plt_defconfig
  4. spacemit_k1_v2_defconfig


your choice (1-4): 

To compile Bianbu Linux 1.0 version, enter 1 and press Enter to start compiling.

To compile Bianbu Linux 2.0 version, enter 4.

The compilation process may require downloading some third-party software packages, and the time required depends on the network environment. If you have downloaded the third-party software packages required by buildroot in advance, the recommended hardware configuration compilation time is about 1 hour.

After the compilation is complete, you will see:

Images successfully packed into /home/username/bianbu-linux/output/k1/images/bianbu-linux-k1.zip


Generating sdcard.img...................................
INFO: cmd: "mkdir -p "/home/username/bianbu-linux/output/k1/build/genimage.tmp"" (stderr):
INFO: cmd: "rm -rf "/home/username/bianbu-linux/output/k1/build/genimage.tmp"/*" (stderr):
INFO: cmd: "mkdir -p "/home/username/bianbu-linux/output/k1/images"" (stderr):
INFO: hdimage(sdcard.img): adding partition 'bootinfo' from 'factory/bootinfo_sd.bin' ...
INFO: hdimage(sdcard.img): adding partition 'fsbl' (in MBR) from 'factory/FSBL.bin' ...
INFO: hdimage(sdcard.img): adding partition 'env' (in MBR) from 'env.bin' ...
INFO: hdimage(sdcard.img): adding partition 'opensbi' (in MBR) from 'opensbi.itb' ...
INFO: hdimage(sdcard.img): adding partition 'uboot' (in MBR) from 'u-boot.itb' ...
INFO: hdimage(sdcard.img): adding partition 'bootfs' (in MBR) from 'bootfs.img' ...
INFO: hdimage(sdcard.img): adding partition 'rootfs' (in MBR) from 'rootfs.ext4' ...
INFO: hdimage(sdcard.img): adding partition '[MBR]' ...
INFO: hdimage(sdcard.img): adding partition '[GPT header]' ...
INFO: hdimage(sdcard.img): adding partition '[GPT array]' ...
INFO: hdimage(sdcard.img): adding partition '[GPT backup]' ...
INFO: hdimage(sdcard.img): writing GPT
INFO: hdimage(sdcard.img): writing protective MBR
INFO: hdimage(sdcard.img): writing MBR
Successfully generated at /home/username/work/bianbu-linux/output/k1/images/bianbu-linux-k1-sdcard.img

Among them, bianbu-linux-k1.zip is suitable for Titan Flasher, or you can unzip it and use fastboot to flash; bianbu-linux-k1-sdcard.img is the sdcard firmware, which can be written to the sdcard using the dd command or balenaEtcher after unzipping.

Titan Flasher User Guide: Flashing Tool User Guide

The default username for the firmware is root, and the password is bianbu.

Configuration

buildroot

Config:

make menuconfig

Save the configuration, which is saved by default to buildroot-ext/configs/spacemit_k1_defconfig:

make savedefconfig

linux

Config:

make linux-menuconfig

Save the configuration, which is saved by default to bsp-src/linux-6.1/arch/riscv/configs/k1_defconfig:

make linux-update-defconfig

u-boot

Config:

make uboot-menuconfig

Save the configuration, which is saved by default to bsp-src/uboot-2022.10/configs/k1_defconfig:

make uboot-update-defconfig

Recompile Completely

If you have already compiled completely using make envconfig, you can directly use make to recompile completely.

Compile Specific Packages

buildroot supports compiling specific packages. You can view the guide with make help.

Common commands:

• Delete the build directory of <pkg>: make <pkg>-dirclean
• Compile <pkg>: make <pkg>

To compile the kernel:

make linux-rebuild

To compile u-boot:

make uboot-rebuild

After compiling the specified package, you can download it to the device for verification or compile it into the firmware:

make

Standalone Compilation

The cross-compiler download URL is http://archive.spacemit.com/toolchain/, and it can be used after decompression.

Such as spacemit-toolchain-linux-glibc-x86_64-v1.0.0.tar.xz:

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

Set environment variables:

export PATH=/opt/spacemit-toolchain-linux-glibc-x86_64-v0.3.3/bin:$PATH
export CROSS_COMPILE=riscv64-unknown-linux-gnu-
export ARCH=riscv

Compile opensbi

cd /path/to/opensbi
make -j$(nproc) PLATFORM_DEFCONFIG=k1_defconfig PLATFORM=generic

The compilation will finally generate platform/generic/firmware/fw_dynamic.itb.

Compile u-boot

cd /path/to/uboot-2022.10
make k1_defconfig
make -j$(nproc)

The compilation will generate u-boot-env-default.bin based on board/spacemit/k1-x/k1-x.env, which corresponds to the image of the env partition in the partition table, and will also generate FSBL.bin and u-boot.itb.

Compile linux

cd /path/to/linux-6.1
make k1_defconfig
LOCALVERSION="" make -j$(nproc)