Can't build for mips-unknown-linux-musl (big endian platforms)

[darrint]

$ cargo build --target mips-unknown-linux-musl   Compiling ring v0.4.3
   Compiling url v1.2.3
   Compiling openssl-sys-extras v0.7.14
   Compiling regex v0.1.80
error: macro undefined: 'u32x2!'
   --> /home/de-user/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.4.3/src/digest/digest.rs:326:9
    |
326 |         u32x2!(0x67452301u32, 0xefcdab89u32),
    |         ^^^^^

error: macro undefined: 'u32x2!'
   --> /home/de-user/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.4.3/src/digest/digest.rs:327:9
    |
327 |         u32x2!(0x98badcfeu32, 0x10325476u32),
    |         ^^^^^

$ cargo --version
cargo 0.13.0-nightly (eca9e15 2016-11-01)

$ rustc --version
rustc 1.13.0 (2c6933acc 2016-11-07)

[briansmith]

If you look at the source code for the u32x2 macro you'll see that it is only defined when the target endianness is little-endian. Therefore, we need somebody to contribute a big-endian implementation in order for this code to compile, which should be easy.

After that, in order to get the code to link, we'd need to get the MIPS assembly source code for all the assembly language modules from OpenSSL. BoringSSL removed all the MIPS assembly language code and ring removed all the non-assembly language code. This second task is quite a bit of work.

[darrint]

Thanks for the info.

[briansmith]

If somebody's interested in getting ring to work on MIPS, I'm happy to assist. At least getting things to compile for big-endian should be easy.

[briansmith]

Closing this as a dupe of #562.