Banana pie bpi-m5 toss record (2) -- compile u-boot

The process of tossing the development board is usually to burn the official release Mirror image , Then I was thinking about compiling myself kernal Making mirrors , Before that, you need to compile u-boot,u-boot It is mainly used to boot and load the kernel ,u-boot The compilation process is recorded as follows .

1 install toolchain

To look at first kernal and u-boot Supported by toolchain edition ：

[email protected]:~/code/BPI5/BSP/BPI-M5-bsp$ find . -name "compiler-gcc*"
./linux-aml/include/linux/compiler-gcc.h
./linux-aml/tools/include/linux/compiler-gcc.h
./u-boot-aml/include/linux/compiler-gcc4.h
./u-boot-aml/include/linux/compiler-gcc3.h
./u-boot-aml/include/linux/compiler-gcc.h
[email protected]:~/code/BPI5/BSP/BPI-M5-bsp$ 

You can see that the supported versions are 3、4, So choose toolchain The version is 4.8, Download link ：

https://releases.linaro.org/archive/13.11/components/toolchain/binaries/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux.tar.xz
https://releases.linaro.org/archive/14.04/components/toolchain/binaries/gcc-linaro-arm-none-eabi-4.8-2014.04_linux.tar.xz

establish toolchain Path and unzip ：

sudo mkdir -p /opt/toolchains
sudo tar xvf gcc-linaro-aarch64-none-elf-4.8-2013.11_linux.tar.xz -C /opt/toolchains/
sudo tar xvf gcc-linaro-arm-none-eabi-4.8-2014.04_linux.tar.xz -C /opt/toolchains/

take toolchain Path to the environment variable ：

sudo vim ~/.bashrc

Add the following at the end of the file ：

export ARCH=arm64
export CROSS_COMPILE=aarch64-none-elf-
export PATH=/opt/toolchains/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin:/opt/toolchains/gcc-linaro-arm-none-eabi-4.8-2014.04_linux/bin:$PATH

Carry out orders , Make the environment variable change take effect immediately ：

source ~/.bashrc

Execute the following command , Test for successful installation ：

aarch64-none-elf-gcc -v

If there are the following similar outputs, the installation is successful ：

Using built-in specs.
COLLECT_GCC=aarch64-none-elf-gcc
COLLECT_LTO_WRAPPER=/opt/toolchains/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux/bin/../libexec/gcc/aarch64-none-elf/4.8.3/lto-wrapper
Target: aarch64-none-elf
......
Thread model: single
gcc version 4.8.3 20131111 (prerelease) (crosstool-NG linaro-1.13.1-4.8-2013.11 - Linaro GCC 2013.10) 

2 u-boot

download souce code:

git clone https://github.com/BPI-SINOVOIP/BPI-M5-bsp
cd BPI-M5-bsp
git submodule update --init --recursive

This process takes a long time to download ,,code It contains kernal and u-boot, Only compile this time uboot, Execute the compile script ：

./build.sh

give the result as follows ：

[email protected]:~/code/BPI5/BSP/BPI-M5-bsp$ ./build.sh 
This tool support following building mode(s):
--------------------------------------------------------------------------------
	1. Build all, uboot and kernel and pack to download images.
	2. Build uboot only.
	3. Build kernel only.
	4. kernel configure.
	5. Pack the builds to target download image, this step must execute after u-boot,
	   kernel and rootfs build out
	6. Update local build to SD with BPI Image flashed
	7. Clean all build.
--------------------------------------------------------------------------------
Please choose a mode(1-7): 

You can see that there is 7 Compile options , compile u-boot Input 2 that will do , Or directly execute the following command to compile u-boot：

./build.sh 2

It will be compiled in BPI-M5-bsp/u-boot-aml/sd_fuse Directory generation u-boot.bin, Prepare a SD card , Execution of the following command will u-boot Burn writing SD card ：

sudo dd if=u-boot.bin of=/dev/mmcblk0 conv=fsync,notrunc bs=512 seek=1
sync

Connect the serial port ,SD Insert the card into the development board , Power up the development board , You can see that the serial port has the startup information printed ：

As soon as the power is on, press the Enter key continuously to enter uboot Command mode , Can output help Command view supported commands ：

thus u-boot Compilation and burning are finished , The process is quite simple .