The fastboot flash command that writes an image to a partition works in
several steps:
1 - Retrieve the maximum size the device can download through the
"max-download-size" variable
2 - Retrieve the partition type through the "partition-type:%s" variable,
that indicates whether or not the partition needs to be erased (even
though the fastboot client has minimal support for that)
3a - If the image is smaller than what the device can handle, send the image
and flash it.
3b - If the image is larger than what the device can handle, create a
sparse image, and split it in several chunks that would fit. Send the
chunk, flash it, repeat until we have no more data to send.
However, in the 3b case, the subsequent transfers have no particular
identifiers, the protocol just assumes that you would resume the writes
where you left it.
While doing so works well, it also means that flashing two subsequent
images on the same partition (for example because the user made a mistake)
would not work withouth flashing another partition or rebooting the board,
which is not really intuitive.
Since we have always the same pattern, we can however maintain a counter
that will be reset every time the client will retrieve max-download-size,
and incremented after each buffer will be flashed, that will allow us to
tell whether we should simply resume the flashing where we were, or start
back at the beginning of the partition.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
The current sparse image parser relies heavily on the MMC layer, and
doesn't allow any other kind of storage medium to be used.
Rework the parser to support any kind of storage medium, as long as there
is an implementation for it.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
The functions and a few define to generate a fastboot message to be sent
back to the host were so far duplicated among the users.
Move them all to a common place.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
To check the alignment of the image blocks to the storage blocks, the
current code uses a convoluted syntax, while a simple mod also does the
work.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
The chunk parsing code was duplicating a lot of code among the various
chunk types, while all of them could be covered by generic and simple
functions.
Refactor the current code to reuse as much code as possible and hopefully
make the chunk parsing loop more readable and concise.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
The current sparse image format parser is quite tangled, with a lot of
code duplication.
Start refactoring it by moving the header parsing function to a function
of its own.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
CHUNK_TYPE_DONT_CARE should skip over the specified number of blocks, but
currently fails to increment the device block address. This results in
filesystem images getting written incorrectly. Add the missing block
address incrementing.
Cc: Steve Rae <srae@broadcom.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Steve Rae <srae@broadcom.com>
Maxime Ripard
Rob Herring
Steve Rae