1 开发环境搭建

注意: 重要！重要！重要！自己编译后的固件，必须先确认io_domains(4.2章节)后，才可以下载到板子运行，否则可能造成烧坏RK3568的情况。

1.1 更新系统

hale@thinkpad:~$ sudo apt-get update

1.2 安装依赖

hale@thinkpad:~$ sudo apt-get install repo git ssh make gcc libssl-devliblz4-toolexpect g++ patchelf chrpath gawk texinfo chrpathdIFfstatbinfmt-supportqemu-user-static live-build bison flex fakeroot cmakegcc-multilibg++-multilib unzip device-tree-compiler python-piplibncurses5-devbuild-essential vim tree

1.3 解压rk3568_sdk

hale@thinkpad:~$ mkdir rk3568_aybering_Android11.0
hale@thinkpad:~$ cat rk3568_aybering_Android11.0_sdk.tar.gz* | tar -zx -C rk3568_aybering_Android11
hale@thinkpad:~$ cd rk3568_aybering_Android11

1.4 编译sdk

1.4.1 准备编译环境

hale@thinkpad:rk3568_aybering_Android11$ source build/envsetup.sh

1.4.2 选择产品

hale@thinkpad:rk3568_aybering_Android11$ lunch 

You're building on Linux

Lunch menu... pick a combo:
     ...
     50. rk3566_r-user
     51. rk3566_r-userdebug
     52. rk3566_rgo-user
     53. rk3566_rgo-userdebug
     54. rk3568_r-user
     55. rk3568_r-userdebug
     ...

Which would you like? [aosp_arm-eng] 55

============================================
PLATFORM_VERSION_CODENAME=REL
PLATFORM_VERSION=11
TARGET_PRODUCT=rk3568_r
TARGET_BUILD_VARIANT=userdebug
TARGET_BUILD_TYPE=release
TARGET_ARCH=arm64
TARGET_ARCH_VARIANT=armv8-a
TARGET_CPU_VARIANT=cortex-a55
TARGET_2ND_ARCH=arm
TARGET_2ND_ARCH_VARIANT=armv8-2a
TARGET_2ND_CPU_VARIANT=cortex-a55
HOST_ARCH=x86_64
HOST_2ND_ARCH=x86
HOST_OS=linux
HOST_OS_EXTRA=Linux-5.4.0-124-generic-x86_64-Ubuntu-18.04.6-LTS
HOST_CROSS_OS=windows
HOST_CROSS_ARCH=x86
HOST_CROSS_2ND_ARCH=x86_64
HOST_BUILD_TYPE=release
BUILD_ID=RQ3A.210705.001
OUT_DIR=out
============================================
hale@thinkpad:rk3568_aybering_Android11$

1.4.3 GPIO电压配置确认

RK3568 GPIO电压没配置对会导致芯片GPIO烧坏，因此需要根据实际硬件原理图，对IO-Domain GPIO电压配置进行确认。

&pmu_io_domains {
    status = "okay";
    pmuio2-supply = <&vcc3v3_pmu>;
    vccio1-supply = <&vccio_acodec>;
    vccio3-supply = <&vccio_sd>;
    vccio4-supply = <&vcc_1v8>;
    vccio5-supply = <&vcc_3v3>;
    vccio6-supply = <&vcc_1v8>;
    vccio7-supply = <&vcc_3v3>;
};

vccio1-supply为例，首先查看硬件原理图确认vccio1电源域（VCCIO1）的配置如图所示：

在硬件原理图上面搜索 VCCIO1 ，如下图：

从上图找到 VCCIO1 的电源是 vccio_acodec 。
在原理图上搜索 vccio_acodec ，可以找到如下图：

从上图找到 vccio_acodec 是由RK809的LDO4供电。
从软件的DTS里面找到LDO_REG4（LDO4）的配置信息,如下

vccio_acodec: LDO_REG4 {
    regulator-always-on;
    regulator-boot-on;
    regulator-min-microvolt = <3300000>;
    regulator-max-microvolt = <3300000>;
    regulator-name = "vccio_acodec";
    regulator-state-mem {
    regulator-off-in-suspend;
};

将上面的 vccio_acodec 配置到pmu_io_domains节点中的vccio1-supply = <&vccio_acodec>;即可完成vccio1的电压配置

&pmu_io_domains {
    status = "okay";
    pmuio2-supply = <&vcc3v3_pmu>;
    vccio1-supply = <&vccio_acodec>;
    vccio3-supply = <&vccio_sd>;
    vccio4-supply = <&vcc_1v8>;
    vccio5-supply = <&vcc_3v3>;
    vccio6-supply = <&vcc_1v8>;
    vccio7-supply = <&vcc_3v3>;`
};

其他几路按照上面的方式配置即可，其中vccio2是硬件固定电压不需要配置

pmuio2
vccio1
vccio3
vccio5
vccio6
vccio7

GPIO电压按照上面的方式配置即可

1.4.4 开始编译sdk

hale@thinkpad:rk3568_aybering_Android11$  source build/envsetup.sh 
hale@thinkpad:rk3568_aybering_Android11$  lunch rk3568_r-userdebug

============================================
PLATFORM_VERSION_CODENAME=REL
PLATFORM_VERSION=11
TARGET_PRODUCT=rk3568_r
TARGET_BUILD_VARIANT=userdebug
TARGET_BUILD_TYPE=release
TARGET_ARCH=arm64
TARGET_ARCH_VARIANT=armv8-a
TARGET_CPU_VARIANT=cortex-a55
TARGET_2ND_ARCH=arm
TARGET_2ND_ARCH_VARIANT=armv8-2a
TARGET_2ND_CPU_VARIANT=cortex-a55
HOST_ARCH=x86_64
HOST_2ND_ARCH=x86
HOST_OS=linux
HOST_OS_EXTRA=Linux-5.4.0-125-generic-x86_64-Ubuntu-18.04.6-LTS
HOST_CROSS_OS=windows
HOST_CROSS_ARCH=x86
HOST_CROSS_2ND_ARCH=x86_64
HOST_BUILD_TYPE=release
BUILD_ID=RD2A.211001.002
OUT_DIR=out
============================================
hale@thinkpad:rk3568_aybering_Android11$

1.4.5 RK356X kernel编译弹出IO-Domain确认对话框

编译kernel时弹出如下对话框：

弹出这个对话框目的是检查实际硬件原理图和软件dts的GPIO电压是否匹配，需要根据硬件原理图的实际设计电压来选择（对话框中选择的值不会保存到dts中，dts需要手动去修改）。如果你是软件工程师请与你们的硬件工程师一起核对确认，这个很重要。如果GPIO电压配置不对会导致芯片GPIO烧坏。当你正确确认GPIO电压后这个对话框就不会在弹出（输入值和dts配置的值相同），如果dts名字或者dts里面的io-domian发生变化，则会在继续弹出进行确认。

1.4.6 编译完成，生成固件路径

hale@thinkpad:rk3568_aybering_Android11$ ls IMAGE/
RK3568_R_USERDEBUG_RK3568-EVB1-DDR4-V10__20220816.1803

至此，开发环境搭建完成