1. For SHA AC, use atomic flag to manage its ownership.
(1) Nuvoton SHA AC doesn't support SHA context save & restore, so S/W
SHA fallback has been supported before. To make non-blocking 'acquire'
semantics clearer, introduce 'try_acquire' to substitute for 'acquire'.
(2) No biting CPU due to mechanism above.
(3) No deadlock due to mechanism above.
2. For AES/DES/ECC AC, change to mutex to manage their ownership.
(1) Change crypto-misc.c to crypto-misc.cpp to utilize C++ SingletonPtr
which guarantees thread-safe mutex construct-on-first-use.
(2) With change to crypto-misc.cpp, add 'extern "C"' modifier to CRYPTO_IRQHandler()
to avoid name mangling in C++.
(3) No priority inversion because mutex has osMutexPrioInherit attribute
bit set.
(4) No deadlock because these AC are all locked for a short sequence
of operations rather than the whole lifetime of mbedtls context.
(5) For double mbedtls_internal_ecp_init() issue, it has been fixed in upper
mbedtls layer. So no need to change ecc init/free flow.
With support for checking H/W UART initialized or not, we can simplify stdio management:
1. When serial_init(&stdio_uart) calls in, just set the 'stdio_uart_inited' flag.
2. When serial_free(&stdio_uart) calls in, just clear the 'stdio_uart_inited' flag.
Except above, we needn't make special handling with 'stdio_uart'.
The same H/W UART may be shared by multiple serial_t objects. This fix tries to avoid
re-configuring the same H/W UART in serial_init() when there are multiple serial_t
objects constructed. To re-configure UART, call serial_baud() and serial_format()
explicitly. This can avoid confusion when e.g. a newly constructed serial_t object
changes baudrate unexpectedly in serial_init().
--legacyalign, --no_legacyalign are deprecated from ARMC6 compiler, in order to
remove deprecated flags all linker files (GCC and IAR as well to have uniformity)
should strictly align to 8-byte boundary
Replace wait_us with nu_busy_wait_us in lp_ticker since wait_us is not allowed in sleep test
which would suspend us ticker layer on which wait_us relies. nu_busy_wait_us is implemented
by calling us ticker HAL API directly rather than relying on us ticker layer.
If us_ticker/lp_ticker is scheduled and then the interrupt is disabled, the originally scheduled
interrupt may still become pending. If this occurs, then an interrupt will fire twice on the next
call to us_ticker_set_interrupt/lp_ticker_set_interrupt - once immediately and then a second time
at the appropriate time.
This patch prevents the first interrupt by clearing interrupts in
us_ticker_set_interrupt/lp_ticker_set_interrupt before calling NVIC_EnableIRQ.
1. Modify PinMode enum to fully support GPIO I/O modes.
2. Translate input pull mode/direction to I/O mode, where H/W doesn't support
separate configuration for input pull mode/direction.
3. Allow for configuring I/O mode in addition to input pull mode.
1. Introduce S/W interrupt enable/disable to reduce calls to TIMER_EnableInt/TIMER_DisableInt.
2. Allow dummy interrupt because clear interrupt flag is not synchronized.
3. Enable LPTICKER_DELAY_TICKS to make lp_ticker_set_interrupt non-blocking.