（一）TF-A移植步骤
基于 Arm 的可信固件 Trusted Firmware-A，简称 TF-A。它是一个开源软件，运行在一个硬件隔离的安全环境中并提供安全服务。（ARMV7后才引入这种方式引导内核启动，以前都是spl的方式）。
2.1》导入源码
1）打开系统源码，进入TF-A的源码目录下,该目录下以 patch 结尾的文件为 ST 官方提供的补丁文件；tf-a-stm32mp-2.2.r1-r0.tar.gz 为标准 tf-a 源码包。
/home/linux/fs_mp157a/kernel/stm32mp1-openstlinux-5.4-dunfell-mp1-20-06-24/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-2.2.r1-r0
2）解压源码包，并且进入解压后的源码目录下
tar -xvf tf-a-stm32mp-2.2.r1-r0.tar.gz
cd tf-a-stm32mp-2.2.r1/
******注意：接下来所有的操作都将在此目录下，不要走错了地方。
3）将 ST 官方补丁文件打到 tf-a 源码中：
for p in ls -1 ../*.patch; do patch -p1 < $p; done
4）导入交叉编译工具链
source /opt/st/stm32mp1/3.1-openstlinux-5.4-dunfell-mp1-20-06-24/environment-setup-cortexa7t2hf-neon-vfpv4-ostl-linux-gnueabi
$CC --version
2.2》增加板级相关文件
1）添加设备树文件
cp fdts/stm32mp15xx-dkx.dtsi fdts/stm32mp15xx-fsmp1x.dtsi
cp fdts/stm32mp157a-dk1.dts fdts/stm32mp157a-fsmp1a.dts
2）修改上层目录下的 Makefile.sdk 编译脚本在 TFA_DEVICETREE 配置项中添加 stm32mp1 57a-fsmp1a
vim …/Makefile.sdk
添加的内容：
TFA_DEVICETREE ?= stm32mp157a-fsmp1a stm32mp157a-dk1 stm32mp157d-dk1 stm32m p157c-dk2 stm32mp157f-dk2 stm32mp157c-ed1 stm32mp157f-ed1 stm32mp157a-ev1 stm32mp 157c-ev1 stm32mp157d-ev1 stm32mp157f-ev1
1）修改 fdts/stm32mp157a-fsmp1a.dts 将 #include “stm32mp15xx-dkx.dtsi” 修改为 #include “stm32mp15xx-fsmp1x.dtsi”
vim fdts/stm32mp157a-fsmp1a.dts
2）编译源码
make -f $PWD/…/Makefile.sdk TFA_DEVICETREE=stm32mp157a-fsmp1a TF_A_CONFIG=trusted ELF_DEBUG_ENABLE=‘1’ all
3）编译完成后会在上级 build/trusted 目录得到如下文件：
ls …/build/trusted/
tf-a-stm32mp157a-fsmp1a-trusted.stm32 就是编译生成的TF-A镜像
2.3》烧录TF-A镜像和u-boot镜像
1）插入SD卡，连接到ubuntu
2）查看分区
ls /dev/sd*
3）进入TF-A的镜像目录
/home/linux/fs_mp157a/kernel/stm32mp1-openstlinux-5.4-dunfell-mp1-20-06-24/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-2.2.r1-r0/build/trusted
4）执行烧录指令，这里只烧录TF-A部分
sudo dd if=tf-a-stm32mp157a-fsmp1a-trusted.stm32 of=/dev/sdb1 conv=fdatasync
sudo dd if=tf-a-stm32mp157a-fsmp1a-trusted.stm32 of=/dev/sdb2 conv=fdatasync
5）进入u-boot的镜像目录
/home/linux/fs_mp157a/kernel/stm32mp1-openstlinux-5.4-dunfell-mp1-20-06-24/sources/arm-ostl-linux-gnueabi/u-boot-stm32mp-2020.01-r0/build-trusted
6）执行烧录指令，这里只烧录u-boot部分
sudo dd if=u-boot-stm32mp157a-fsmp1a-trusted.stm32 of=/dev/sdb3 conv=fdatasync
7）启动开发板 。
将拨码开关设置为 SD 卡启动方式，将SD卡插入开发板卡槽。连接J-link工具，打开Xshell。重新上电。
这个错误产生的原因是电源初始化错误，需重新调整电源相关配置
2.4》调整设备树电源
1）回到TF-A源码目录：
/home/linux/fs_mp157a/kernel/stm32mp1-openstlinux-5.4-dunfell-mp1-20-06-24/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-2.2.r1-r0/tf-a-stm32mp-2.2.r1
2）去掉原有电源管理内容，修改 fdts/stm32mp15xx-fsmp1x.dtsi 文件
vim fdts/stm32mp15xx-fsmp1x.dtsi
将文件中 i2c4 节点相关内容整体删除，删除内容如下：
&i2c4 {
pinctrl-names = “default”, “sleep”;
pinctrl-0 = <&i2c4_pins_a>;
pinctrl-1 = <&i2c4_pins_sleep_a>;
i2c-scl-rising-time-ns = <185>;
i2c-scl-falling-time-ns = <20>;
clock-frequency = <400000>;
status = “disabled”;
/内容太长此处省略/
watchdog {
compatible = “st,stpmic1-wdt”;
status = “disabled”;
};
};
};
3）修改 fdts/stm32mp15xx-fsmp1x.dtsi 文件，删除如下内容：
vim fdts/stm32mp15xx-fsmp1x.dtsi
删除内容如下：
&cpu0{
cpu-supply = <&vddcore>;
};
&cpu1{
cpu-supply = <&vddcore>;
};
4）添加固定电源配置
修改 fdts/：stm32mp15xx-fsmp1x.dtsi
vim fdts/stm32mp15xx-fsmp1x.dtsi
固定电源配置通常添加在根节点下，在根节点末尾位置添加如下内容(红色字体为需要添加的内容)：
vin: vin {
compatible = “regulator-fixed”;
regulator-name = “vin”;
regulator-min-microvolt = <5000000>;
regulator-max-microvolt = <5000000>;
regulator-always-on;
};
v3v3: regulator-3p3v {
compatible = “regulator-fixed”;
regulator-name = “v3v3”;
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
regulator-always-on;
regulator-boot-on;
};
v1v8_audio: regulator-v1v8-audio {
compatible = “regulator-fixed”;
regulator-name = “v1v8_audio”;
regulator-min-microvolt = <1800000>;
regulator-max-microvolt = <1800000>;
regulator-always-on;
regulator-boot-on;
};
v3v3_hdmi: regulator-v3v3-hdmi {
compatible = “regulator-fixed”;
regulator-name = “v3v3_hdmi”;
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
regulator-always-on;
regulator-boot-on;
};
v1v2_hdmi: regulator-v1v2-hdmi {
compatible = "regulator-fixed";
regulator-name = "v1v2_hdmi";
regulator-min-microvolt = <1200000>;
regulator-max-microvolt = <1200000>;
regulator-always-on;
regulator-boot-on;
};
vdd: regulator-vdd {
compatible = "regulator-fixed";
regulator-name = "vdd";
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
regulator-always-on;
regulator-boot-on;
};
vdd_usb: regulator-vdd-usb {
compatible = "regulator-fixed";
regulator-name = "vdd_usb";
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
regulator-always-on;
regulator-boot-on;
};
};
5）重新编译源码
make -f $PWD/…/Makefile.sdk TFA_DEVICETREE=stm32mp157a-fsmp1a TF_A_CONFIG=trusted ELF_DEBUG_ENABLE=‘1’ all
6）烧写后，再启动。u-boot不用重新烧录了，只需要重新烧录TF-A
进入TF-A的镜像目录
/home/linux/fs_mp157a/kernel/stm32mp1-openstlinux-5.4-dunfell-mp1-20-06-24/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-2.2.r1-r0/build/trusted
执行烧录指令，这里只烧录TF-A部分
sudo dd if=tf-a-stm32mp157a-fsmp1a-trusted.stm32 of=/dev/sdb1 conv=fdatasync
sudo dd if=tf-a-stm32mp157a-fsmp1a-trusted.stm32 of=/dev/sdb2 conv=fdatasync
7）启动开发板
2.5》eMMC移植
参考原理图可知 eMMC 使用的是 SDMMC2 总线，当前所使用的设备树文件中没有 SDMMC2 的支持，所以需要增加相关内容才能正常驱动 eMMC。
1）回到TF-A源码目录：
/home/linux/fs_mp157a/kernel/stm32mp1-openstlinux-5.4-dunfell-mp1-20-06-24/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-2.2.r1-r0/tf-a-stm32mp-2.2.r1
2）增加 SDMMC2 节点信息
修改 fdts/stm32mp15xx-fsmp1x.dtsi 增加 SDMMC2 的信息
vim fdts/stm32mp15xx-fsmp1x.dtsi
在原有 sdmmc1 节点下增加 sdmmc2 的内容
&sdmmc2 {
pinctrl-names = “default”;
pinctrl-0 = <&sdmmc2_b4_pins_a &sdmmc2_d47_pins_a>;
non-removable;
st,neg-edge;
bus-width = <8>;
vmmc-supply = <&v3v3>;
vqmmc-supply = <&v3v3>;
status = “okay”;
};
1）测试
重新编译
make -f $PWD/…/Makefile.sdk TFA_DEVICETREE=stm32mp157a-fsmp1a TF_A_CONFIG=trusted ELF_DEBUG_ENABLE=‘1’ all
烧写后，再启动。u-boot不用重新烧录了，只需要重新烧录TF-A
进入TF-A的镜像目录
/home/linux/fs_mp157a/kernel/stm32mp1-openstlinux-5.4-dunfell-mp1-20-06-24/sources/arm-ostl-linux-gnueabi/tf-a-stm32mp-2.2.r1-r0/build/trusted
执行烧录指令，这里只烧录TF-A部分
sudo dd if=tf-a-stm32mp157a-fsmp1a-trusted.stm32 of=/dev/sdb1 conv=fdatasync
sudo dd if=tf-a-stm32mp157a-fsmp1a-trusted.stm32 of=/dev/sdb2 conv=fdatasync
4）启动开发板------多了MMC：1
