haiku/docs/develop/drivers/disk/ioctls.txt
Adrien Destugues cef80a1fb7 devfs: translate partition offsets in B_TRIM_DEVICE
Fixes bfs part of #10336. Untested on SATA (don't have a testing drive
to sacrifice) but working fine on SD/MMC.

This requires moving the copy from kernel to userland into the devfs. As
a result the code in the disk drivers becomes a bit simpler.

Also add some documentation for the common ioctls to implement for a
disk device.

Change-Id: Ie84b6a1d293828d33902a64b3c9d4b19aa6eacb1
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3640
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
2021-01-23 12:20:59 +00:00

43 lines
1.3 KiB
Plaintext

Here is a list of ioctls usually implemented by disk devices.
B_GET_DEVICE_SIZE
The parameter is a size_t and is filled with the disk size in bytes.
This is limited to 4GB and not very useful. B_GET_GEOMETRY is used instead.
B_GET_GEOMETRY
The parameter is a device_geometry structure to be filled with the device geometry.
B_GET_ICON_NAME
Deprecated. Get the name of an icon to use. The icons are hardcoded in Tracker.
B_GET_VECTOR_ICON
The parameter is a device_icon structure to be populated with the icon data in HVIF format.
This icon is then used to show the disk in Tracker, for example.
B_EJECT_DEVICE
Eject the device (for removable devices).
B_LOAD_MEDIA
Load the device (reverse of eject) if possible.
B_FLUSH_DRIVE_CACHE
Make sure all data is stored on persistent storage and not in caches (including any caching inside
the device)
B_TRIM_DEVICE
The parameter is an fs_trim_data structure. It is guaranteed to be in kernel memory because
the partition manager pre-processes requests coming from userland and makes sure no sectors
are outside the partition range for a specific partition device.
Mark the listed areas on disk as unused, allowing future reads to these areas to return
random data or read errors. Flash memory devices (SSD, MMC, ...) may use this information
to optimize their internal storage.