Samsung EXYNOS--->
--- Samsung EXYNOS
[] SAMSUNG EXYNOS3
SAMSUNG EXYNOS4
[] SAMSUNG EXYNOS5
*** EXYNOS SoCs ***
-*- SAMSUNG EXYNOS4210
SAMSUNG EXYNOS4412
配置调试串口 - 设置为UART2
Kernel hacking--->
Kernel low-level debugging functions (read help!)
Kernel low-level debugging port (Use Samsung S3C UART 2 for low-level debug)--->
开启串口调试驱动
Device Drivers--->
Character devices--->
Serial drivers--->
Samsung SoC serial support
Samsung SoC serial debug
Support for console on Samsung SoC serial port
开启DM96XX网卡驱动
Device Drivers--->
Network device support--->
USB Network Adapters--->
Davicom DM96xx based USB 10/100 ethernet devices
设置内核压缩模式为LZMA(非必须，可减小文件大小)
General setup--->
()Build ID Salt
Kernel compression mode (LZMA)--->
编译内核
~/linux-5.4$ make uImage LOADADDR=0x40008000 -j$(nproc)
...
OBJCOPY arch/arm/boot/zImage
Kernel: arch/arm/boot/zImage is ready
UIMAGEarch/arm/boot/uImage
Image Name: Linux-5.4.47
Created: Sun Jun 21 22:41:40
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 5337464 Bytes = 5212.37 KiB = 5.09 MiB
Load Address: 40008000
Entry Point:40008000
Kernel: arch/arm/boot/uImage is ready
这里需要指定LOADADDR变量，才能生成正确的uImage文件。因为在uboot启动内核时，会先解析uImage中的前64B头信息，定义如下：
3. 修改设备树(以适配开发板)
3.1 说明
在前面的步骤完成后，已经能够编译出可以运行的内核了，但是最后还需要根据板子的差异性，对设备树文件进行调整，以适配目标板。
3.2 修改
屏蔽掉firmware节点(安全相关，不启用，也不知道怎么用…)
修改bus_dmc 节点devfreq-events为devfreq-event
修改regulators 节点参数(参考原理图中的参数)
修改如下：
--- a/arch/arm/boot/dts/exynos4412-itop-scp-core.dtsi
+++ b/arch/arm/boot/dts/exynos4412-itop-scp-core.dtsi
@@ -23,10 +23,12 @@
reg = <0x40000000 0x40000000>;
};
+#if 0
firmware@203f000 {
compatible = "samsung,secure-firmware";
reg = <0x0203F000 0x1000>;
};
+#endif
fixed-rate-clocks {
xxti {
@@ -70,7 +72,7 @@
};
&bus_dmc {
-devfreq-events = , ;
+devfreq-event = , ;
vdd-supply = ;
status = "okay";
};
@@ -167,8 +169,8 @@
regulators {
ldo1_reg: LDO1 {
regulator-name = "VDD_ALIVE";
- regulator-min-microvolt = <1100000>;
- regulator-max-microvolt = <1100000>;
+ regulator-min-microvolt = <1000000>;
+ regulator-max-microvolt = <1000000>;
regulator-always-on;
regulator-boot-on;
op_mode = <1>; /* Normal Mode */
@@ -230,8 +232,8 @@
ldo9_reg: LDO9 {
regulator-name = "VDD33_LCD";
- regulator-min-microvolt = <3300000>;
- regulator-max-microvolt = <3300000>;
+ regulator-min-microvolt = <3000000>;
+ regulator-max-microvolt = <3000000>;
op_mode = <1>; /* Normal Mode */
};
@@ -252,8 +254,8 @@
ldo12_reg: LDO12 {
regulator-name = "VDD33_UOTG";
- regulator-min-microvolt = <3300000>;
- regulator-max-microvolt = <3300000>;
+ regulator-min-microvolt = <3000000>;
+ regulator-max-microvolt = <3000000>;
regulator-always-on;
op_mode = <1>; /* Normal Mode */
};
@@ -300,8 +302,8 @@
/* Used by HSIC */
ldo18_reg: LDO18 {
regulator-name = "VDDIOPERI_28";
- regulator-min-microvolt = <3300000>;
- regulator-max-microvolt = <3300000>;
+ regulator-min-microvolt = <2800000>;
+ regulator-max-microvolt = <2800000>;
regulator-always-on;
op_mode = <1>; /* Normal Mode */
};
@@ -313,15 +315,15 @@
ldo20_reg: LDO20 {
regulator-name = "VDD28_CAM";
- regulator-min-microvolt = <1800000>;
- regulator-max-microvolt = <2800000>;
+ regulator-min-microvolt = <3000000>;
+ regulator-max-microvolt = <3000000>;
op_mode = <1>; /* Normal Mode */
};
ldo21_reg: LDO21 {
regulator-name = "VDD28_AF";
- regulator-min-microvolt = <1800000>;
- regulator-max-microvolt = <2800000>;
+ regulator-min-microvolt = <3000000>;
+ regulator-max-microvolt = <3000000>;
op_mode = <1>; /* Normal Mode */
};
@@ -341,8 +343,8 @@
ldo24_reg: LDO24 {
regulator-name = "VDD33_A31";
- regulator-min-microvolt = <3300000>;
- regulator-max-microvolt = <3300000>;
+ regulator-min-microvolt = <3000000>;
+ regulator-max-microvolt = <3000000>;
op_mode = <1>; /* Normal Mode */
};
@@ -430,8 +432,8 @@
buck7_reg: BUCK7 {
regulator-name = "pvdd_buck7";
- regulator-min-microvolt = <750000>;
- regulator-max-microvolt = <2000000>;
+ regulator-min-microvolt = <2050000>;
+ regulator-max-microvolt = <2050000>;
regulator-boot-on;
regulator-always-on;
op_mode = <1>; /* Normal Mode */
3.3 编译dts
~/linux-5.4$ make dtbs
4. 启动测试
根据另一个专题《Uboot--11移植DM9621网卡专题》移植的支持网络功能的uboot，和移植的ubuntu-base-20.04-base-armhf文件系统(下篇文章更新移植方法)，可以直接tftp测试内核，效果如下：
到这一步，移植工作就完成了，是不是觉得很容易呢~
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