Linux下，如何验证SD/EMMC卡？
Linux下mmc_test测试工具使用很多朋友也都有疑问，如何在Linux下，测试emmc/sd模块呢？
当然，mmc core提供了mmc_test.c来作为mmc driver的测试文件。
如何使用mmc_test.c测试文件测试mmc 驱动呢？
1、将mmc_test.c编译到内核默认情况下，mmc_test.c是独立的文件，并没有编译到内核中，需要我们到menuconfig中手动打开。
打开的配置有：CONFIG_MMC_TEST、CONFIG_MMC_DEBUG、CONFIG_DEBUG_FS三个配置。
注意：CONFIG_MMC_TEST，该选项可以选择M和*，分别对应为：编译成模块或者直接编译到内核
这里我们选择*
2、mmc_test绑定默认情况下，我们一般都已经加载了mmc driver，那么要想使用mmc_test工具测试，需要将mmc设备绑定到该mmc_test驱动上。
2.1、查看驱动编号通过下面命令，查询对应的mmc编号，如下：mmc0:0001，忽略掉\
代码语言：javascript复制ls /sys/bus/mmc/drivers/mmcblk/mmc0\:0001/
2.2、解绑mmc原驱动代码语言：javascript复制echo mmc0:0001 > /sys/bus/mmc/drivers/mmcblk/unbind
2.3、绑定mmc_test驱动代码语言：javascript复制echo mmc0:0001 > /sys/bus/mmc/drivers/mmc_test/bind
2.4、debugfs挂载代码语言：javascript复制mount -t debugfs none /sys/kernel/debug
2.5、查看测试列表代码语言：javascript复制cd /sys/kernel/debug/mmc0/mmc0\:0001/
cat testlist
代码语言：javascript复制0: Run all tests
1: Basic write (no data verification)
2: Basic read (no data verification)
3: Basic write (with data verification)
4: Basic read (with data verification)
5: Multi-block write
6: Multi-block read
7: Power of two block writes
8: Power of two block reads
9: Weird sized block writes
10: Weird sized block reads
11: Badly aligned write
12: Badly aligned read
13: Badly aligned multi-block write
14: Badly aligned multi-block read
15: Correct xfer_size at write (start failure)
16: Correct xfer_size at read (start failure)
17: Correct xfer_size at write (midway failure)
18: Correct xfer_size at read (midway failure)
19: Highmem write
20: Highmem read
21: Multi-block highmem write
22: Multi-block highmem read
23: Best-case read performance
24: Best-case write performance
25: Best-case read performance into scattered pages
26: Best-case write performance from scattered pages
27: Single read performance by transfer size
28: Single write performance by transfer size
29: Single trim performance by transfer size
30: Consecutive read performance by transfer size
31: Consecutive write performance by transfer size
32: Consecutive trim performance by transfer size
33: Random read performance by transfer size
34: Random write performance by transfer size
35: Large sequential read into scattered pages
36: Large sequential write from scattered pages
37: Write performance with blocking req 4k to 4MB
38: Write performance with non-blocking req 4k to 4MB
39: Read performance with blocking req 4k to 4MB
40: Read performance with non-blocking req 4k to 4MB
41: Write performance blocking req 1 to 512 sg elems
42: Write performance non-blocking req 1 to 512 sg elems
43: Read performance blocking req 1 to 512 sg elems
44: Read performance non-blocking req 1 to 512 sg elems
45: Reset test
46: Commands during read - no Set Block Count (CMD23)
47: Commands during write - no Set Block Count (CMD23)
48: Commands during read - use Set Block Count (CMD23)
49: Commands during write - use Set Block Count (CMD23)
50: Commands during non-blocking read - use Set Block Count (CMD23)
51: Commands during non-blocking write - use Set Block Count (CMD23)
2.6、测试指定命令代码语言：javascript复制echo number > test
number：是上面的测试序号。
如：echo 1 > test
代码语言：javascript复制mmc0: Starting tests of card mmc0:0001...
mmc0: Test case 1. Basic write (no data verification)...
mmc0: Result: OK
这个工具可以尽可能的帮助我们测试SD/EMMC卡，使用起来吧！