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kvasir-io / Kvasir

C++ Metaprogramming library enabling better static checking and register abstraction in embedded software
Apache License 2.0
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register offset addition results in >32 bits and -Wc++11-narrowing #108

Open jacquelinekay opened 7 years ago

jacquelinekay commented 7 years ago

Some registers sum the base address and register offset to a result that requires more than 32 bits/4 bytes, which is invalid for a 32-bit address space. For example:

https://github.com/kvasir-io/Kvasir/blob/master/Lib/Chip/Unknown/STMicro/STM32L15xxE/GPIOE.hpp#L6

This results in -Wc++11-narrowing when trying to compile code that includes the header, since the type of all register field values is unsigned.

This is the section from the SVD that results in the addition: https://github.com/posborne/cmsis-svd/blob/master/data/STMicro/STM32L15xxE.svd#L4172-L4183

As you can see, 0x40021000 + 0xFFFFF800 = 0x140020800

I came across this while compiling tests for the new generator. I am not sure how to fix it; it seems like there's either a mistake in the SVD file or we're missing a step in how to sum the offset and the base address. Do we need to apply a different operator? Do we need to wrap around? Am I missing something with my assumption about the size of the address space?

CvRXX commented 7 years ago

@odinthenerd Do you know how this works?

odinthenerd commented 7 years ago

check out http://www.st.com/content/ccc/resource/technical/document/reference_manual/cc/f9/93/b2/f0/82/42/57/CD00240193.pdf/files/CD00240193.pdf/jcr:content/translations/en.CD00240193.pdf page 47. The SVD is screwed up.