上一篇《x210項目重新回顧之三.....》只是基礎部分移動（包含兩階段，重定位），這節移植mmc，細節可看朱老師課程https://edu.51cto.com//center/course/lesson/index?id=85183。
直接拷貝三星官方uboot裏的mmc驅動，做修改
代碼鏈接：https://github.com/jimingkang/news5pv210/tree/master/u-boot-2013.10
代碼變動如下：
>git status
1.修改 : board/samsung/goni/Makefile
增加 COBJS-y := goni.o setup_hsmmc.o
2. 修改: board/samsung/goni/goni.c
直接修改int board_mmc_init(bd_t *bis)函數內容：
{
#ifdef CONFIG_S3C_HSMMC
setup_hsmmc_clock();
setup_hsmmc_cfg_gpio();
return smdk_s3c_hsmmc_init();
#else
return 0;
#endif
}
3.直接替換: common/cmd_mmc.c
4.修改: drivers/mmc/Makefile
添加：COBJS-$(CONFIG_S3C_HSMMC) += s3c_hsmmc.o
註釋#COBJS-$(CONFIG_GENERIC_MMC) += mmc_write.o
5.直接替換: drivers/mmc/mmc.c
6.修改: include/configs/s5p_goni.h
/* MMC */
#define CONFIG_GENERIC_MMC
#define CONFIG_MMC
//#define CONFIG_SDHCI
//#define CONFIG_S5P_SDHCI
//jimmy add for mmc
#define CONFIG_S3C_HSMMC // 添加這一行添加上新的移植過來的驅動文件
/* IROM specific data */
#define SDMMC_BLK_SIZE (0xD003A500)
#define COPY_SDMMC_TO_MEM (0xD003E008)
/* The macro for MMC channel 0 is defined by default and can't be undefined */
#define USE_MMC0
#define USE_MMC2
#define MMC_MAX_CHANNEL 4
7. 直接替換: include/mmc.h
8.（新增）
board/samsung/goni/setup_hsmmc.c
drivers/mmc/s3c_hsmmc.c
include/s3c_hsmmc.h
燒些後，輸出：
-------------------------------------------------
CPU: S5PC110@400MHz
Board: Goni
I2C: ready
DRAM: 464 MiB
Board PMIC init
MMC: 3776MB (顯示了卡槽2的sd大小)
In: serial
Out: serial
Err: serial
Net: Net Initialization Skipped
No ethernet found.
Hit any key to stop autoboot: 0
Goni # mmc
Usage:
MMC sub system
Goni # mmc read 300000000 1# 1
MMC Device 300000000 not found
Goni # mmc read 1 300000000 1# 1
MMC read: dev # 1, block # 1, count 1 ...1 blocks read: OK
Goni # print
baudrate=115200
bootargs=root=/dev/nfs rw nfsroot=172.16.96.215:/arm-nfs,proto=tcp,nfsvers=3,nolock ip=172.16.96.253:172.16.96.215:172.16.96.1:255.255.254.0::eth0:off console=ttySAC2,115200 init=/linuxrc
bootcmd=movi read kernel 30008000; movi read rootfs 30B00000 300000; bootm 30008000 30B00000
bootdelay=3
ethaddr=00:40:5c:26:0a:5b
gatewayip=172.16.96.215
ipaddr=172.16.96.253
mtdpart=80000 400000 3000000
netmask=255.255.254.0
serverip=172.16.96.215
Environment size: 476/16380 bytes
Goni # movi
Unknown command 'movi' - try 'help'
Goni # md 300000000 4
00000000: ea00002a eafffffe eafffffe eafffffe *...............
Goni # mmc help
Goni # mmc read 1 30000000 1# 1
MMC read: dev # 1, block # 1, count 1 ...1 blocks read: OK
Goni # md 30000000
30000000: 00002000 00000000 000d8a67 00000000 . ......g.......
Goni # mmc list
S3C_HSMMC0_dev0
S3C_HSMMC2_dev1（這個就是卡槽2的卡，也就是我們燒寫用的）
Goni # help mmc
mmc - MMC sub system
Usage:
mmc read <device num> addr blk# cnt
mmc write <device num> addr blk# cnt
mmc rescan <device num>
mmc list - list available devices
Goni # md 31000000 （顯示內存31000000處內容）
31000000: a4251c3d 90a83015 0c254e2c 904a1206 =.%..0..,N%...J.
Goni # mw.l 31000000 12345678 （修改內存31000000處內容）
Goni # md 31000000
31000000: 12345678 90a83015 0c254e2c 904a1206 xV4..0..,N%...J.
Goni # mmc write 1 31000000 1# 1 （把修改的內存31000000處內容，寫入卡槽2的sd中，覆蓋了uboot，下次啓動出錯）
MMC write: dev # 1, block # 1, count 1 ... 1 blocks written: OK
Goni # mmc read 1 33000000 1# 1 （再把卡槽2的sd中1扇區的內容讀到33000000處）
Goni # md 33000000 （顯示內存33000000處內容）
33000000: 12345678 90a83015 0c254e2c 904a1206 xV4..0..,N%...J.