printf of 64bit value on ARM
Mon Dec 12 12:41:00 GMT 2011
On 28/11/11 17:45, Jeff Johnston wrote:
> Did you make sure to include stdio.h in your test case? This can cause
> problems with the variable parameter list. If you have already included
> stdio.h, I would suggest debugging _VFPRINTF_R in vprintf.c and
> verifying the variable list long long parameter is being passed and
> restored correctly on the other end (look at the arg_val union). From
> debugging, you should also verify that the long long code was enabled
Perhaps even more important, for Cortex-M3 you have to either make sure
that the processor config bit STKALIGN is set, or you have to make sure
all top-level 'interrupt' routines are compiled with the 'interrupt'
> -- Jeff J.
> On 11/27/2011 05:14 PM, Franzi Edo. wrote:
>> I am trying to build a newlib for a Cortex M3 ARM capable to support the printf.
>> Everything works fine, but I have a strange behavior with the printf of 64bit values.
>> If I execute this:
>> uint64_t val = 1LL;
>> printf("value = %llu\n", val);
>> I got: value = 4294967296
>> This sounds like a big-little endian problem. Any idea how to solve this problem?
>> I uses the newlib 1.19.0 and gcc 4.6.2.
>> For the newlib configure I use these switches:
>> --enable-newlib-io-long-long \
>> --enable-interwork \
>> --disable-libgloss \
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