Fixed FS command IO buffer
Revert "Revert "stm32_i2c: ensure that unexpected ISR can't overwrite stale data""

This reverts commit 7a7a07ed0ec492b3ab9f87467189886a66b2fc1a.
stm32_i2c: fixed timeout handling

thanks to hxxnrx@gmail.com for noticing this
stm32_i2c: ensure we don't change priv-> after semaphore is released

this prevents a race condition where a subsequent I2C transfer could
be lost

Many thanks to hxxnrx@gmail.com for reporting this bug
stm32_i2c: check for msgc underflow in I2C ISR

a spurious I2C interrupt could cause priv->msgc to underflow, leading
to memory being overwritten. This seems to have been the cause of at
least some of lockups we have seen
stm32_i2c: handle more unexpected ISR conditions

this clears the interrupt for more unexpected ISR conditions that
otherwise lead to an ISR storm. When that happens no user threads are
able to run as the I2C ISR is continually raised

Thanks to Lorenz for help in tracking this down
STM32:  Handle setting of USART CR1_M when 8 bits of data plus parity
Add "#ifdef CONFIG_ARCH_IRQPRIO" where needed
Merge pull request #21 from PX4/irqprio

Add "#ifdef CONFIG_ARCH_IRQPRIO" where needed
stm32_i2c: handle more error conditions on I2C bus

this fixes a I2C ISR storm condition where status=0x70084, which can
happen with some specific types of noise on the I2C bus. This was
reproduced by playing 80s rock through a Jabra wireless headset close
to the I2C cables.
Merge pull request #23 from tridge/pullrequest-i2c-lockup-fix

stm32_i2c: handle more error conditions on I2C bus
Force a hardfault on stack overflows to make the fault condition obvious once it occurs
Cleanup of docs / comments
lib_sscanf: fixed a hang in scanf() on end of string

if we reach end of buffer when we are not on a format specifier then
the code would loop forever.
Merge pull request #24 from tridge/pullrequest-sscanf-hang

lib_sscanf: fixed a hang in scanf() on end of string
ARM math.h: Remove commented out code parts
Fixing md5 hashing when digest[$i] lower that 16.  Sergey <sectus@mail.ru>