Re: [avr-gcc-list] Re: [Bug target/31786] error: unable to find a register to spill in class 'BASE_POINTER_REGS'

[Joerg Wunsch]

Joel Sherrill <address@hidden> wrote:

>> I would strongly suggest that you and Joel take a look at avr-libc
>> again: it has printf, many string functions, etc.

> Does it support file IO?

It doesn't, but that's mainly due to a lack of any kind of a usable
file system to implement file IO on top of, as the AVR itself doesn't
offer anything like a native filesystem.  If someone were to draft
e.g. a memory "file system", implementing fopen() should be not too
hard.

What is your newlib implementation using to back its files on?

> At the bottom of the implementation of the stdio library what gets
> called?  write() or an output character function?

Whatever has been supplied to fdevopen().  Consequently, fopen() would
then use its own internal backend write and read functions that
somehow work on a file in its filesystem.

> I suspect a lot of code will have to be disabled to even build with
> a small libc.

Hmm, might be interesting to test some day.  I'm willing to add more
stuff to avr-libc if it makes sense.  Obviously, a lot of the Posix
functionality you are quoting has to be delivered by the operating
system itself, not by the library, so that would be RTEM's turn
anyway.

> I have attached the .h files installed by our newlib RPM.

I can only see this:

"package rtems-4.8-avr-rtems4.8-newlib-1.15.0-12.fc5 is not installed"

-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)