Some targets may not provide zero-wait-state flash performance. Export this function
to be overridable for targets to provide more accurate implementation like locating
'delay_loop_code' in SRAM.
Imports working McuBoot for reset.
Updates microsec ticker driver.
Default baudrate is set to 115200 to see TF-M boot messages.
Stack top is set to scatter file dependent and not hard-coded.
Volatile makes no real difference when we're using assembler, or locked
functions, but leaving it off could be more efficient for the basic
loads and stores. So add non-volatile overloads in C++ for them.
Reimplement atomic code in inline assembly. This can improve
optimisation, and avoids potential architectural problems with using
LDREX/STREX intrinsics.
API further extended:
* Bitwise operations (fetch_and/fetch_or/fetch_xor)
* fetch_add and fetch_sub (like incr/decr, but returning old value -
aligning with C++11)
* compare_exchange_weak
* Explicit memory order specification
* Basic freestanding template overloads for C++
This gives our existing C implementation essentially all the functionality
needed by C++11.
An actual Atomic<T> template based upon these C functions could follow.
Once a fatal error is in progress, it's not useful to trap RTX errors
or mutex problems, so short-circuit the checks.
This makes it more likely that we may be able to get the console
initialised if it is being written to for the first time by `mbed_error`
in a difficult context - such as an RTX error callback from inside an
SVCall.
For example, the one-line program
osMutexAcquire(NULL, 0);
will generate an RTX error trap, then `mbed_error` will try to call
`write(STDERR_FILENO)` to print the error, which will prompt mbed_retarget to
construct a singleton `UARTSerial`. This would trap in the mutex
for the singleton or the construction of the UARTSerial itself, if
we didn't allow this leniency. If we clear the mutex checks, then
`UARTSerial::write_unbuffered` will work.
User uses of `MBED_MAKE_ERROR` assemble a new error that gets its bottom
16 bits from an existing negative 32-bit error code. This lead to
undefined behaviour when `<<` was used on it - even though it was a
shift by zero!
Avoid the undefined behaviour warning from Clang by masking before
shifting.
In rtos-less code, heap is defined by assuming one-region. Through weak-reference to
ARM_LIB_HEAP, heap definition is fixed if ARM_LIB_HEAP is defined.
Please note the heap address of the both the banks must not be contigious else
GCC considers it to be single memory bank and does allocation across the banks,
which might result into hard-fault
Assert failure took a critical section before calling `mbed_error`.
There's no need to take a critical section on assert failure -
mbed_error does not do this, and is designed to operate from normal
contexts.
Avoiding the critical section will improve the chances of console
initialisation due to assert failure working nicely.
New `target.console-uart` option added to indicate whether a target has
a console UART on STDIO_UART_TX/RX/RTS/CTS pins. (The existing option
`target.console-uart-flow-control` indicates whether RTS and or CTS is
available in addition to TX and RX).
The option defaults to true, and is currently true on all platforms. It
only applies if DEVICE_SERIAL is true, so no need to go through and mark
it false for non-SERIAL platforms.
An application can turn off target.console-uart to save ROM/power/etc if
they don't want to use the serial console. If this is turned off, the
console won't be activated for stdin/stdout, but the application is
still free to open `UARTSerial(STDIO_UART_TX, STDIO_UART_RX)`
themselves.
Chun-Chieh Li
Martin Kojtal
Jaakko Korhonen
Gabor Kertesz
Marcus Chang
Kevin Bracey
M. Rahimi
Anna Bridge
Deepika
Cruz Monrreal
Shrikant Tudavekar
d-kato
David Saada
Mahesh Mahadevan
Michael Schwarcz
Senthil Ramakrishnan
Jimmy Brisson