Zig Cross Compiling

My first cross-compiling attempt with zig was great.

I wanted to compile my podcast player on the big x86_64 machine to run on the smaller aarch64 FuriPhone FLX1 phone.

Both run Linux, and I had already successfully compiled on the phone itself, but the edit/debug cycle was too long.

So first up, find out what the phone target is, by running zig targets which produces tons of output, but at the bottom:

 "native": {
  "triple": "aarch64-linux.4.19.325...4.19.325-gnu.2.39",
  "cpu": {
   "arch": "aarch64",
   "name": "cortex_a78",

So let's try that:

$zig build -Dtarget=aarch64-linux.4.19.325...4.19.325-gnu.2.39

But I got this error:

/home/dvanderson/.cache/zig/p/122004e82d4a0c61a9c414539c1f87bb125cb2b293573af77b153ea3903cb209b65b/library/aesce.c:182:18: 
error: always_inline function 'vaesimcq_u8' requires target feature 'aes', 
but would be inlined into function 'mbedtls_aesce_inverse_key' 
that is compiled without support for 'aes'

It looks like I need to also pass some -Dcpu=, so again using the output of zig targets from above:

$zig build -Dtarget=aarch64-linux.4.19.325...4.19.325-gnu.2.39 -Dcpu=cortex_a78

And that worked!

Note that this is all with zig 0.13, and there are a few issues that might change how to pass the target/cpu/libc/abi information in the future.