June 2017
Intermediate to advanced
478 pages
13h 14m
English
Content preview from Mastering Embedded Linux Programming - Second Edition
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The block drivers: /sys/block
There is one more view of the device model that is important to this discussion: the block driver view that you will find in /sys/block. There is a subdirectory for each block device. This example is taken from a BeagleBone Black:
# ls /sys/blockloop0 loop4 mmcblk0 ram0 ram12 ram2 ram6 loop1 loop5 mmcblk1 ram1 ram13 ram3 ram7 loop2 loop6 mmcblk1boot0 ram10 ram14 ram4 ram8 loop3 loop7 mmcblk1boot1 ram11 ram15 ram5 ram9
If you look into mmcblk1, which is the eMMC chip on this board, you can see the attributes of the interface and the partitions within it:
# ls /sys/block/mmcblk1 alignment_offset ext_range mmcblk1p1 ro bdi force_ro mmcblk1p2 size capability holders power slaves dev inflight queue stat device ...
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