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Linux Kernel
3.7.1
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Linux Kernel
3.7.1
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#include <ubi.h>
Data Fields | |
| int | ubi_num |
| int | leb_size |
| int | leb_start |
| int | min_io_size |
| int | max_write_size |
| int | ro_mode |
| dev_t | cdev |
struct ubi_device_info - UBI device description data structure. : ubi device number : logical eraseblock size on this UBI device : starting offset of logical eraseblocks within physical eraseblocks : minimal I/O unit size : maximum amount of bytes the underlying flash can write at a time (MTD write buffer size) : if this device is in read-only mode : UBI character device major and minor numbers
Note, is the logical eraseblock size offered by the UBI device. Volumes of this UBI device may have smaller logical eraseblock size if their alignment is not equivalent to %1.
The field describes flash write maximum write unit. For example, NOR flash allows for changing individual bytes, so is %1. However, it does not mean than NOR flash has to write data byte-by-byte. Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when writing large chunks of data, they write 64-bytes at a time. Obviously, this improves write throughput.
Also, the MTD device may have N interleaved (striped) flash chips underneath, in which case can be physical min. I/O size of single flash chip, while can be N * .
The field is always greater or equivalent to . E.g., some NOR flashes may have ( = 1, = 64). In contrast, NAND flashes usually have = = NAND page size.
1.8.2