commit 83a1db41e98a687b55d0f074bbf7a46e276646b1
author Gianfranco Valentino <gevalentino@google.com> Mon Apr 12 23:45:31 2021 +0000
committer CQ Bot <commit-bot@chromium.org> Mon Apr 12 23:45:31 2021 +0000
tree 3edc4382363fc13640cfabfd30dfe0716187ff5e
parent 7a6db41b6cfa33efe0f32d108c165a100245fc03

[volume_image]: Introduce MTD Writer.

Small layer on top of ftl-mtd library for writing directly to raw nand
in linux. This combined with block writer added previously adds the
remainig bits for replacing pave.

This test is only meaningful in linux for now, since there are no other
use cases at the moment for paving directly to raw nand.

The test verifies success of the mtd writer. In order to reproduce
outside of CQ users need to create a ram mtd device and grant permission
to users.

Command to generate the mtd device.
sudo modprobe nandsim id_bytes=0x2c,0xdc,0x90,0xa6,0x54,0x0 badblocks=5

Then
chmod u=rw,og=rw /dev/mtd0

Added ftl_io.h which provides an interface 'FtlHandle' to generate
readers and writes to a FTL instance. In order to load a new instance,
the volume in the handle must be flushed, so data is persisted.

Moved the InMemoryNdm and InMemoryRawNand to a shared test header to
test the ftl_io constructs. Then provided a MTD layer, which
instantiates a FTL on top of a MTD device. Added to tests:

1) Verifies that arbitrary content is read back correctly.
2) Write a FVM, then write the same FVM to a file, and do a block by
block comparison of the contents. This is a paranoid use case.

Test: storage-volume-image-test
Change-Id: I5c33ee55934442e334dccf6e0dc6ed16725dae5f
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/512775
Commit-Queue: Gianfranco Valentino <gevalentino@google.com>
Reviewed-by: James Sullivan <jfsulliv@google.com>