Fix unaligned 16-bit access in swap_regs() - #130
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swap_regs() byte-swapped each register through 16-bit indexed writes (data[n]) on buffers that point directly into the message buffer, which is not guaranteed to be 2-byte aligned. On cores that require aligned memory accesses this triggers a HardFault. The issue is not observable on cores that support unaligned memory accesses, but was reproducable on Cortex-M0/M0+. Perform the byte swap in place through a uint8_t pointer so that only byte-wide accesses are used, making the function alignment-agnostic. Signed-off-by: Sandesh Ashok <sandesh.ashok@cpp.canon>
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swap_regs() byte-swapped each register through 16-bit indexed writes (data[n]) on buffers that point directly into the message buffer, which is not guaranteed to be 2-byte aligned. On cores that require aligned memory accesses this triggers a HardFault. The issue is not observable on cores that support unaligned memory accesses, but was reproducable on Cortex-M0/M0+.
Perform the byte swap in place through a uint8_t pointer so that only byte-wide accesses are used, making the function alignment-agnostic.