Using the AES interrupt allows the user process not to waste time
polling for the completion of the operation. This time can be used by
the user process to do something else, or to let the system enter PM0.
Since the system is now free to perform various operations during a
crypto operation, a protection of the crypto resource is added, and PM1+
is prohibited in order not to stall crypto operations.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
This is safer because the previous code assumed that the start and end
VMAs of .data and .bss were word-aligned, which is not always the case,
so the initialization code could write data outside these sections. The
ROM functions support any address boundary.
This is faster because the ROM functions are ultra optimized, using
realignment and the LDM/STM instructions, which is much better than the
previous simple loops of single word accesses.
This is smaller because the ROM functions don't require to add any code
to the target device other than simple function calls.
This makes the code simpler and more maintainable because standard
functions are not reimplemented and no assembly is used.
Note that this is also faster and smaller than the corresponding
functions from the standard string library.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
The initialization code clearing .bss is allowed to use the stack, so
the stack can not be in .bss, or this code will badly fail if it uses
the stack.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
Some toolchains, like Sourcery CodeBench Lite 2013.05-23 arm-none-eabi
(http://sourcery.mentor.com/public/gnu_toolchain/arm-none-eabi/)
automatically force the alignment of an output section LMA to use the
maximum alignment of all its input sections. This toolchain uses GNU
binutils 2.23, and this automatic behavior is the same as the manual
behavior of the ALIGN_WITH_INPUT feature of GNU binutils 2.24+.
This behavior is not an issue per se, but it creates a gap between
_etext and the LMA of the .data output section if _etext does not have
the same alignment, while reset_handler() initialized this section by
copying the data from _etext to its VMA, hence an offset in the
addresses of loaded data, and missing data.
This commit fixes this issue by making reset_handler() directly use the
LMA of the .data section using LOADADDR(.data), rather than assuming
that _etext is this LMA.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
