Linux4.9.9内核SD卡移植（适配fs4412平台）

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本文适配fs4412开发板，使用的内核为linux4.9.9。
1.修改设备树

vi arch/arm/boot/dts/exynos4412-liebao.dts

修改：

&sdhci_2 {
   bus-width = <4>;                                                                                                                                              
     pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_bus4 &sd2_cd>;
     pinctrl-names = "default";
     vmmc-supply = <&mmc_reg>;
    status = "okay";
};
为：
&sdhci_2 {
    bus-width = <4>;                                                                                                                                              
          pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_bus4>;
cd-gpios = <&gpx0 7 0>;
cd-inverted = <0>;
      pinctrl-names = "default";
     // vmmc-supply = <&mmc_reg>;
     status = "okay";
};

2.配置内核

make menuconfig

2.1 配置SD卡驱动

Device Drivers --->
<*> MMC/SD/SDIO card support --->
<*> Secure Digital Host Controller Interface support
<*> SDHCI support on Samsung S3C SoC

2.2 文件系统的支持

File systems --->
DOS/FAT/NT Filesystems --->
<*> MSDOS fs support
<*> VFAT (Windows-95) fs support
(437) Default codepage for FAT
(iso8859-1) Default iocharset for FAT

2.3 本地语言编码支持

-*- Native language support --->
<*> Codepage 437 (United States, Canada)
<*> Simplified Chinese charset (CP936, GB2312)
<*> ASCII (United States)
<*> NLS ISO 8859-1 (Latin 1; Western European Languages)
<*> NLS UTF-8

3.编译内核和设备树

 make uImage -j2 LOADADDR=0X40008000
make dtbs

4 .测试
拷贝内核和设备树文件到/tftpboot 目录下

cp arch/arm/boot/uImage /tftpboot
cp arch/arm/boot/dts/exynos4412-liebao.dtb /tftpboot/

启动开发板:
将SD卡插入开发板，关注终端打印信息。

[  499.301302] mmc0: new high speed SDHC card at address 1234
[  499.305842] mmcblk0: mmc0:1234 SA04G 3.71 GiB
[  499.312642]  mmcblk0: p1

挂载， 注意不要挂在 C EMMC 的分区

$ mount -t vfat /dev/mmcblk0p1 /mnt

查看/mnt/目录即可看到 sd 卡中内容

注：有关linux4.9.9内核的移植见《移植最新的linux4.9.9内核（适配fs4412平台）》：
http://blog.csdn.net/liebao_han/article/details/79436819

文章内容持续更新。