cn-cbor not portable for MCU that doesn't support alignment about cn-cbor HOT 6 OPEN

I've made several tests with a cortex M0, and this lib seems not compatible with these kind of CPU.
I'm experiencing tons of problems, especially with this part : https://github.com/cabo/cn-cbor/blob/master/src/cn-cbor.c#L138-L140

So for now, forget about my previous comment. There's other things to do to be compatible with Cortex MCU..

I'll see if I can do something about that.

from cn-cbor.

Yes, the ntohxxp functions assume that you can do unaligned reads.
I have pushed a workaround in branch "unaligned".
(TODO: This clearly can be done better, and there needs to be a proper way to set CBOR_CAN_DO_UNALIGNED_READS.)

from cn-cbor.

Hello,

Thank you for this branch. I'll try your branch once I'd find time and let you know if it works.

from cn-cbor.

BTW, just for the historical record:
Just including <arpa/inet.h> is not expensive (at least not on my machine):

alma:tmp cabo$ cat ai1.c
#include <arpa/inet.h>

int f() {return 1;}
alma:tmp cabo$ size ai1.o
__TEXT  __DATA  __OBJC  others  dec hex
75  0   0   32  107 6b
alma:tmp cabo$ cat ai2.c
int f() {return 1;}
alma:tmp cabo$ size ai2.o
__TEXT  __DATA  __OBJC  others  dec hex
75  0   0   32  107 6b
alma:tmp cabo$ 

Contiki (where this code was used before) defines its own ntohl.
But we did use a Cortex-M3 for those tests, IIRC, so we didn't encounter the unaligned access problem.

from cn-cbor.

Indeed, M3 supports address alignment, which is not the case of M0.
If what you've done works as expected, I suggest to fix this code, which will increase the portability of this lib.

from cn-cbor.

Ok, I've found time to test, and it works like a charm.
There's also an include of arpa/inet.h in cn-encoder.c, line 11 (https://github.com/cabo/cn-cbor/blob/unaligned/src/cn-encoder.c#L11) that should also be surrounded by #ifdef CBOR_CAN_DO_UNALIGNED_READS

Do you plan to merge these change in master ?

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