mbed_sdk_init called twice on IAR without RTOS.

[jamike]

1-mbed_sdk_init is called after __iar_data_init3 (zero initilaized and sdata recopy from flash)
2 mbed_sdk_init is called in __iar_argc_argv : this call can be removed

[0xc0170]

It's first called in the cmain.S file: https://github.com/mbedmicro/mbed/blob/03d8ea8e96051c0fa2d0a081f9f84b9c86d9ffb2/hal/targets/cmsis/TOOLCHAIN_IAR/cmain.S#L53

Second time: https://github.com/mbedmicro/mbed/blob/8e8f389d3a10724626ce0eec4c14c9ff6cde79e0/hal/common/retarget.cpp#L548

I would remove it from cmain.S, as in retarget most of toolchains have it there (mbed sdk init call), not to bring confusion that we missed sdk_init call. However, looking at the PR #780 and the code in cmain.s, there's an intention why mbed sdk init is called prior init array. Looking at it from toolchains perspective, that cmain should not invoke mbed sdk init, because the rest don't do it (they invoke sdk init right before main).

Please send a fix.

cc @c1728p9

[jamike]

__iar_dynamic_initialization ( initialize C++ global object) is just called after this 1st call to mbed_sdk_init..
if we remove this 1st call to mbed_sdk_init, and the initiliazed C++ needs access to hardware IP which relies on SysCoreClock value for a correct hardware init, it will not work. that's why I propose to remove the call from ___iar_argc_argv.
On the other if we look at the other toolchain init (except gcc_arm :in which the zero initialized and recopy of sdata is done at start up, before SystemInit which set SystemCoreClock correctly for ever without the need to call SystemCoreClockupdate in mbed_sdk_init ) :ARM , uARM call mbed_sdk_init tool late (after C++ initialization : _cpp_initialize__aeabi)

[0xc0170]

On the other if we look at the other toolchain init (except gcc_arm :in which the zero initialized and recopy of sdata is done at start up, before SystemInit which set SystemCoreClock correctly for ever without the need to call SystemCoreClockupdate in mbed_sdk_init ) :ARM , uARM call mbed_sdk_init tool late (after C++ initialization : _cpp_initialize__aeabi)

this shall be another issue, where we can continue with how to unify startup.

This was resolved via #2129 (2x mbed sdk init call for IAR)