Re: Porting to mips64el

[Andreas Enge]

Am Dienstag, 19. Februar 2013 schrieb Nikita Karetnikov:

> > Nixos on my machine uses the abi n32 (long and void* have 32 bits,

> > long long 64). I would like to switch to abi 64 (long with 64 bits);

> > we might be the first distribution supporting this mode.

>

> I think that the above contradicts the following.

>

> > In the debian distribution also installed on the machine,

> > there is a separate lib64 directory, and it is enough to pass the flag

> > "-mabi= 64" to gcc.

>

> Is it supported in Debian?

 

Yes, you can compile programs in 64 bit mode. But if you do nothing special, they end up being 32 bits. And all packages (except for a few gcc libraries and zlib) are 32 bits. My suggestion is to have the full distribution in 64 bit abi.

 

> Also, what about compatibility? Are there any downsides?

 

Libraries compiled with one abi are incompatible with libraries compiled with another abi. But that would not matter since our system would be consistent. Pointers take more space.

 

> I'll give it a try if you provide detailed instructions.

 

Good question, I do not know myself yet how to achieve the goal! Maybe it would be enough to provide "CFLAGS=-mabi64" in the bootstrap process; or 'CFLAGS="-march=mips64 -mabi64"'. Or maybe we need to create new bootstrap binaries with these flags.

 

Andreas