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