Is a block device driver a file system driver (FAL + FMD )?

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Is a block device driver a file system driver (FAL + FMD?

FAL, FMD, file system, device, Driver

This post was last edited by aggio
You are confused.
Is the block device driver a file system driver (FAL + FMD?
No, but I don't know what the difference is.

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Sorry, I went to happy weekend. I didn't come up yet.
A block device driver is a stream device driver that reads data in blocks.
Because it belongs to the category of stream drivers, it is also the interface form of xxx_init xxx_read xxx_write xxx_iocontorl.
However, this kind of driver is often used for storage devices, so it is usually prefix with DSK _, and it has a fixed iclass = {..........}, you just need to find a sample. All block device drivers will be stored and discovered by the Device Manager. Because the local iclasswill allow device.exe filesys.exe to work, the latter notifies the subordinate Storage Manager to load the file system specified by the block device driver and mount the partitions on the storage device.
Iocontorl driven by Block devices usually contains fixed read and write ioctlcode. The upper-layer file system or other middleware can use these two interfaces to access data. The minimum unit of access is block, the default value is 512 bytes. Thanks to the block-driven fixed interface model, the system can achieve maximum platform portability when designing upper-level file systems and other middleware. For example, although the SD card and the NAND drive are different, but because the interfaces provided externally are block device interfaces, the file system can recognize and load them. Even if you switch to another SOC platform, the file system and storage management do not need to be changed. The upper layer of the block device can also be a file system. For example, when the device is used as the massstorage client, the USB client driver will directly access the block Device Driver Interface, the data access service provided to the USB Host section.
In Ce, the block device driver has its own exclusive category (iclass). CE will differentiate the drive of the iclass with the block device driver from that of the general device driver. For example, in power management, the driver of a block device must enter the power saving status at the end of the suspend process, while in resume, the first driver enters the power recovery status, to ensure the normal operation of the system (because file systems similar to binfs are built on the basis of block device drivers, the upper-layer architecture will be suspended after the foundation cannot work)
Your question is, is FAL + FMD a block device driver?
The answer is block device driver. FAL + FMD is Microsoft's NAND drive architecture. Similar to MDD + PDD, FAL + FMD implements a complete block device driver, of course, according to Microsoft's habits, the external stream interface and the platform-independent logic layer will be implemented on the MDD layer, that is, the FAL layer, the driver of the Controller related to the hardware platform is FMD.