u-boot/doc/usage/cmd/host.rst
Simon Glass 2851cc94f3 dm: Add documentation for host command and implementation
Document the 'host' command and also the internals of how it is
implemented.

Signed-off-by: Simon Glass <sjg@chromium.org>
2022-11-07 16:24:30 -07:00

116 lines
2.2 KiB
ReStructuredText

.. SPDX-License-Identifier: GPL-2.0+
host command
============
Synopis
-------
::
host bind [-r] <label> [<filename>]
host unbind <label|seq>
host info [<label|seq>]
host dev [<label|seq>]
Description
-----------
The host command provides a way to attach disk images on the host to U-Boot
sandbox. This can be useful for testing U-Boot's filesystem implementations.
Common arguments:
<label|seq>
This is used to specify a host device. It can either be a label (a string)
or the sequence number of the device. An invalid value causes the command
to fail.
host bind
~~~~~~~~~
This creates a new host device and binds a file to it.
Arguments:
label
Label to use to identify this binding. This can be any string.
filename:
Host filename to bind to
Flags:
-r
Mark the device as removable
host unbind
~~~~~~~~~~~
This unbinds a host device that was previously bound. The sequence numbers of
other devices remain unchanged.
host info
~~~~~~~~~
Provides information about a particular host binding, or all of them.
host dev
~~~~~~~~
Allowing selecting a particular device, or (with no arguments) seeing which one
is selected.
Example
-------
Initially there are no devices::
=> host info
dev blocks label path
Bind a device::
=> host bind -r test2 2MB.ext2.img
=> host bind fat 1MB.fat32.img
=> host info
dev blocks label path
0 4096 test2 2MB.ext2.img
1 2048 fat 1MB.fat32.img
Select a device by label or sequence number::
=> host dev fat
Current host device: 1: fat
=> host dev 0
Current host device: 0: test2
Write a file::
=> ext4write host 0 0 /dump 1e00
File System is consistent
7680 bytes written in 3 ms (2.4 MiB/s)
=> ext4ls host 0
<DIR> 4096 .
<DIR> 4096 ..
<DIR> 16384 lost+found
4096 testing
7680 dump
Unbind a device::
=> host unbind test2
=> host info
dev blocks label path
1 2048 fat 1MB.fat32.img
Return value
------------
The return value $? indicates whether the command succeeded.