AVR-Chat

> The generated code will look something like this excerpt:
> 26a:    0e 94 3b 01     call    0x276
> 26e:    0c 94 4e 48     jmp     0x909c
> 00000276 <main>:
> 276:    ff cf           rjmp    .-2
>
> Leaving out the return statement (as is commonly done) produces the
> same result and no compiler warnings.

One thing I want to get to ASAP is seeing the generated asm code!

>> Does C (or Winavr) init a declared variable to some
>> defined state ALWAYS, or do I have to?
> Simply stated, the C standard requires a compiler to initialize
> statically allocated variables to zero.  Consequently, if you define
> a variable outside of a function (or inside a function with the
> static attribute) it is guaranteed to be initialized to zero in the
> absence of an explicit initialization.  No such guarantee is made
> for dynamically allocated variables, i.e., those defined within a
> function but not having the static attribute.

Ok, that makes sense, but it conflicts with other input I've been given.

I do understand that it is always safe if I manually init the
variables, and that might be "best practice" on an unconstrained or
lightly constrained system, but I want to definitely know one way or
the other what's happening under the hood.

In ASM, I typically pave all SRAM to 0 just before launching main. I
figure that this will at least start me in a known state, and either
allow things to work (99-> 100% of the time), or break 100% of the
time, as opposed to having ram contain random data.


>There is no longer a Flash size penalty for explicit zero initialization of variables.

Ok, and I like that, but that's compiler-specific.

Given that I'm just starting out, I'm trying to be very careful on
what I accept as "True"