tree 03133e406371e92ce12b03b50c61a82637eea827
parent dc7dc27211808db34f8f24c56a3f9808d7a41298
parent 3215268af977d6dbf8a59771fb175228b5179ba1
author Tom Rini <trini@konsulko.com> 1680735587 -0400
committer Tom Rini <trini@konsulko.com> 1680735587 -0400

Merge branch '2023-04-05-blkmap-composable-virtual-block-devices'

To quote the author:
Block maps are a way of looking at various sources of data through the
lens of a regular block device. It lets you treat devices that are not
block devices, like RAM, as if they were. It also lets you export a
slice of an existing block device, which does not have to correspond to
a partition boundary, as a new block device.

This is primarily useful because U-Boot's filesystem drivers only
operate on block devices, so a block map lets you access filesystems
wherever they might be located.

The implementation is loosely modeled on Linux's "Device Mapper"
subsystem, see the kernel documentation [1] for more information.

The primary use-cases are to access filesystem images stored in RAM, and
within FIT images stored on disk. See doc/usage/blkmap.rst for more
details.

The architecture is pluggable, so adding other types of mappings should
be quite easy.

[1]: https://docs.kernel.org/admin-guide/device-mapper/index.html