u-boot中mmc命令使用
2014 年 2 月 9 日
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div id=”content” contentScore=”249″>[u-boot: v2013.01]
[Author: Bo Shen voice.shen@gmail.com]
mmc命令的帮助信息如下：
U-Boot> mmc
mmc – MMC sub system
Usage:
mmc read addr blk# cnt
mmc write addr blk# cnt
mmc erase blk# cnt
mmc rescan
mmc part – lists available partition on current mmc device
mmc dev [dev] [part] – show or set current mmc device [partition]
mmc list – lists available devices
当系统启动后，系统会将mci0设置为当前设备。使用mmcinfo就可以看到插入到mmc controller 0的sdcard信息。
U-Boot> mmcinfo
Device: mci
Manufacturer ID: 3
OEM: 5344
Name: SD04G
Tran Speed: 25000000
Rd Block Len: 512
SD version 2.0
High Capacity: Yes
Capacity: 3.8 GiB
Bus Width: 4-bit
如果SoC支持多个mmc controller并且使能，使用mmc list来查看使能了几个， 可以通过mmc dev来查看当前是那个设备，或者通过mmc dev 来切换。
像我的系统支持两个mmc controller.
U-Boot> mmc list (显示有几个mmc controller)
mci 0
mci 1
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U-Boot> mmc dev (显示当前是那个device)
mmc1 is current device
U-Boot> mmc dev 0 (设置0为当前设备)
mmc0 is current device
如果，换sdcard，则使用mmc rescan来重新获取sdcard信息
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U-Boot> mmc rescan (重新scan当前设备)
mci: setting clock 257812 Hz, block size 512
mci: setting clock 22000000 Hz, block size 512
mci: setting clock 257812 Hz, block size 512
gen_atmel_mci: CMDR 00001048 ( 8) ARGR 000001aa (SR: 0c100025) Command Failed
mci: setting clock 257812 Hz, block size 512
mci: setting clock 22000000 Hz, block size 512
U-Boot> mmcinfo (列出当前设备的信息)
Device: mci
Manufacturer ID: 1
OEM: 5041
Name: SK512
Tran Speed: 25000000
Rd
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