Broken by 635cfa.
On an stm32 the heap is formed from
const uintptr_t g_idle_topstack = HEAP_BASE;
where HEAP_BASE is &_bss + CONFIG_IDLE_STACKSIZE.
Both these values are not deterministic. One
comes from the compiler, the other the system
configurator.
a 3 byte bss and 250 byte stack would lead to
and unaligned address used as the heap to be.
The compiler used clever `strd r1,r3,[r5,#8]` to
store 2 values in one memory cycle into the
heap_impl struct. Resulting in a hardfault.
Change the amount of bss or the CONFIG_IDLE_STACKSIZE
could lead to a non-functional NuttX system.
85f0bc591e