这个就是往一个地址空间里面写对应数据的测试命令。

你可以参考着这个：http://processors.wiki.ti.com/index.php/DM816x_C6A816x_AM389x_DDR3_Init#Run_mtest

Run mtest

Simple memory test can be run from the U-Boot prompt using the mtest command. The syntax of the command mtest command is given below:

 mtest <start-address> <end-address> <test pattern> <# of iterations>

This command incrementally writes the test pattern to the memory range specified and then reads it back. Running the memory test with a few patterns should be sufficient for checking out the memory.

Run the memory test over the DDR address space of the EMIFs one by one:

 TI8168_EVM# mtest 0x80000000 0xA0000000 0xaa55aa55 3 (referred as Test A)
 TI8168_EVM# mtest 0xA0000000 0xC0000000 0xaa55aa55 3 (referred as Test B)

You can try different patterns (say all 0s, then all Fs and so on) to be sure of the memory reliability.