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Diffstat (limited to 'doc/arch/sandbox/block_impl.rst')
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diff --git a/doc/arch/sandbox/block_impl.rst b/doc/arch/sandbox/block_impl.rst new file mode 100644 index 0000000000..344c74f718 --- /dev/null +++ b/doc/arch/sandbox/block_impl.rst @@ -0,0 +1,39 @@ +.. SPDX-License-Identifier: GPL-2.0+ */ +.. Copyright (c) 2014 The Chromium OS Authors. +.. sectionauthor:: Simon Glass <sjg@chromium.org> + +Sandbox block devices (implementation) +====================================== + +(See :ref:`sandbox_blk` for operation) + +Sandbox block devices are implemented using the `UCLASS_HOST` uclass. Only one +driver is provided (`host_sb_drv`) so all devices in the uclass use the same +driver. + +The uclass has a simple API allowing files to be attached and detached. +Attaching a file results in it appearing as a block device in sandbox. This +allows filesystems and whole disk images to be accessed from U-Boot. This is +particularly useful for tests. + +Devices are created using `host_create_device()`. This sets up a new +`UCLASS_HOST`. + +The device can then be attached to a file with `host_attach_file()`. This +creates the child block device (and bootdev device). + +The host device's block device must be probed before use, as normal. + +To destroy a device, call host_destroy_device(). This removes the device (and +its children of course), then closes any attached file, then unbinds the device. + +There is no arbitrary limit to the number of host devices that can be created. + + +Uclass API +---------- + +This is incomplete as it isn't clear how to make Sphinx do the right thing for +struct host_ops. See `include/sandbox_host.h` for full details. + +.. kernel-doc:: include/sandbox_host.h |