Ignore doxygen builds temporay object database

Update doxyfile_options that has settings used by developer.mbed.org ...

Should be kept in sync with doxygen_options.json which is used for
building the doxygen which is used by docs.mbed.com It is intended
only generate doxygen for specific directories which present the
public APIs for mbed OS

Fix doxygen warnings.

Fix doxygen warnings.

Fix doxygen warnings.

Merge pull request #4365 from LMESTM/fix_i2C_pcf_F1F2F4L1 ...

Fix i2c communication with pcf8574 on stm32 targets of f1, f2, f4 and l1 families

Merge pull request #4368 from MultiTechSystems/iar_fix ...

MTS_DRAGONFLY_F411RE/MTS_MDOT_F411RE: add IAR to post_binary_hook toolchains

Merge pull request #4420 from hisener/master ...

Update CONTRIBUTING.md

Merge pull request #4436 from NXPmicro/Fix_USB_Driver ...

Issue#4250: Fix USB driver for Kinetis devices

Merge pull request #4295 from Patater/armv8m ...

Update uVisor to v0.28.1

uVisor: Import uVisor v0.28.1

uVisor: Remove process_malloc.h from uvisor-lib.h

uVisor: Wrap _memalign_r and _calloc_r

RTX5: uVisor: Switch threads very carefully ...

uVisor doesn't set the PSP of the target thread. The RTOS sets the PSP
of the target thread from the target thread's TCB. However, when
interrupts of higher priority than PendSV happen between the call to
uVisor to switch boxes, and the RTOS setting PSP, the uVisor vIRQ
interrupt handler will attempt to use an invalid PSP (the PSP from
before the box and thread switch). This leads to a crash. Make box and
thread switching atomic by disabling interrupts immediately before the
box switching until immediately after the new PSP is set.

Merge pull request #4087 from geky/localfs-fslike-fix ...

LocalFileSystem: Repair the FileSystemLike hooks

Merge pull request #4438 from 0xc0170/dev_realtek ...

Add REALTEK_RTL8195AM to mbed-os

Resolve conflict in builtin type names ...

In class MBRBlockDevice the tole32 function had used union member
names u32 and u8. The introduction of REALTEK_RTL8195AM cauesd a
conflict with type names in basic_types given they're aliased as
macros to uint32_t and uint8_t respectively.

spi: Added default spi_master_block_write implementation to REALTEK_RTL8195AM ...

There is an easy default implementation of spi_master_block_write that
just calls spi_master_write in a loop, so the default implementation
of spi_master_block_write has been added to all targets.

fix STRINGIFY redefining issue

fix icf file misspelling

clean up GPL license with APACHE2.0

remove unsupported device_name

Switch to rtx2 ...

remove rtx and switch to rtx2

exporter coding style fix ...

should use space instead of tab

fix multiple i2c peripherals possible conflicting issue

Add support for mbed exporter ...

(uvision, gcc_arm, iar)

resolve RTWInterface initialization run after error issue

add comment for the delay in analogout_api.c ...

see analogout_init()

improve coding style

cmsis5\rtx5 put NVIC vector ops in mbed_boot.c