A Sector Map Parameter Table contains a sequence of the following
descriptors:
* (Optional) configuration detection command descriptors, one for
each command to run to determine the current configuration. This
exists only if the flash layout is configurable.
* Sector map descriptors, one for each possible configuration. On
a flash device with a non-configurable layout, there is only one
such descriptor.
Previously we only supported the non-configurable case with a single
descriptor. This commit adds support for multiple configurations.
The SFDP functions parse SFDP data which is fetched by a callback
called `sfdp_reader` provided by {SPIF,QSPIF,OSPIF}BlockDevice.
Currently, this callback interface only takes a read address and an RX
buffer to store output data. This has been enough, because other SPI
parameters are always the same when fetching the SFDP table only -
they are just hardcoded in each reader.
But in the future we will add support for flash devices with multiple
configurations (in a subsequent commit), and to detect which
configuration is enabled, we will need to send detection commands
which require device-dependent SPI parameters:
* address size
* instruction
* dummy cycles
This commit
* turns the above SPI parameters from predefined/hardcoded values
into parameters of the callback
* lets the SFDP functions pass the above parameters to the callback
(Note: To read the SFDP table itself, those values are constants
defined by the standard, not tied to any particular device, so they
can be known to the SFDP functions)
* updates the callbacks implemented by {SPIF,QSPIF,OSPIF}BlockDevice
* updates the mock callback for unit tests and expectations
When passing an allocation size directly to `std::make_unique`,
`std::nothrow` is unavailable, so any failed allocation results in
an exception which we cannot catch because Mbed OS is compiled with
`-fno-exceptions`. To fix this, chain `std::make_unique` with
`new (std::nothrow)`, and the allocated `unique_ptr` retains the
`nullptr` property.
A flash device with no sector map table has uniform sectors, and we
treat the whole flash as one region. In this case the function
`sfdp_parse_sector_map_table()` sets the single region's size and high
boundary accordingly, but it lacks setting of region count to 1, so
users of the SFDP parser may not get the correct number of regions.
This commit fixes the issue.
When a flash chip's SFDP table has no sector map, we treat the whole
flash as a single region. As an optimization, this should only be
done if there is indeed no sector map.
Lingkai Dong