Flash: Support writing single bytes to EEPROM

[dbrgn]

EEPROM supports single-byte writes.

This also changes the pointer type from u32 to usize.

[hannobraun]

Looks good to me. I haven't tested, but since it seems to work for you, that's good enough for me.

I'm not too sure about changing the pointer type to usize. As far as I can see, that doesn't make any difference, except to make the code less explicit. I don't think it's a big deal though.

I'm leaving this open in case we want to talk about the usize change some more, but as far as I'm concerned, this can be merged.

[dbrgn]

As far as I can see, that doesn't make any difference, except to make the code less explicit.

For me, it's more explicit. The type is now "unsigned integer the size of pointer" (which is fitting since it stores pointers), while u32 is just "a 32 bit unsigned integer". For me it's mostly about the semantics, not about the actual size.

Edit: In theory, it also makes the code more portable, in case ST would release a new line of 64 bit microcontrollers with similar peripherals. However, I don't think that argument has any practical value, since there would surely be other differences as well.

[hannobraun]

For me, it's more explicit. The type is now "unsigned integer the size of pointer" (which is fitting since it stores pointers), while u32 is just "a 32 bit unsigned integer". For me it's mostly about the semantics, not about the actual size.

Yeah, that makes sense. Convinced.