This insures the common exception handler will not be
re-entered. The handler does not support nested interrupts
and the interrupt stack pointer and context will be overwritten
resulting in hard to debug hardfaults.
If all the priorities are equal the NVIC prevents the
preemption. The startup code defaults all the priorities
to the same value 128.
This change safeguards in 2 ways 1) By disabling
CONFIG_ ARCH_IRQPRIO: up_prioritize_irq cannot be called.
This will insure that all HW interrupts are at the same
priority.
2) By disabling CONFIG_ARCH_HIPRI_INTERRUP, the common
exception will disable any interrupts during interrupt
processing.
This is needed for companions with high baudrate and high data rate.
Tested with 1500000 Baudrate and mavlink TX rate of ~120KB/s: no drops.
I did not test the exact limit, something like 2500 might be enough. But
we (still) have enough free RAM on FMU-v5.
* Backport:stm32f7: stm32_allocateheap: allow use DTCM memory for heap
Back port of upstrem contrib by Jussi Kivilinna <jussi.kivilinna@haltian.com>
stm32f7: stm32_allocateheap: allow use DTCM memory for heap
STM32F7 has up to 128KiB of DTCM memory that is currently left unused.
This patch adds DTCM to main heap if CONFIG_STM32F7_DTCMEXCLUDE is not enabled.
* px4fmu-v5_default:Enable inclusion of the DTCM in the heap
CONFIG_MM_REGIONS=3 adds the DTCM region to the heap.
This saves almost 2kb of RAM when using the mavlink shell. 70 matches the
size of the mavlink message. Since the pipe is blocking, a process writing
a lot of data will just wait, data will not be dropped.
The mavlink shell is the only process creating a pipe.
Daniel Agar
David Sidrane
Beat Küng
Lorenz Meier
Lorenz Meier