You can use stdenv.hostPlatform.emulator to get an executable that
runs cross-built binaries. This could be any emulator. For instance,
we use QEMU to emulate Linux targets and Wine to emulate Windows
targets. To work with qemu, we need to support custom targets.
I’ve reworked the cross tests in pkgs/test/cross to use this
functionality.
Also, I’ve used talloc to cross-execute with the emulator. There
appears to be a cross-execute for all waf builds. In the future, it
would be nice to set this for all waf builds.
Adds stdenv.hostPlatform.qemuArch attrbute to get the qemuArch for
each platform.
Since years I'm not maintaining anything of the list below other
than some updates when I needed them for some reason. Other people
is doing that maintenance on my behalf so I better take me out but
for very few packages. Finally!
Following legacy packing conventions, `isArm` was defined just for
32-bit ARM instruction set. This is confusing to non packagers though,
because Aarch64 is an ARM instruction set.
The official ARM overview for ARMv8[1] is surprisingly not confusing,
given the overall state of affairs for ARM naming conventions, and
offers us a solution. It divides the nomenclature into three levels:
```
ISA: ARMv8 {-A, -R, -M}
/ \
Mode: Aarch32 Aarch64
| / \
Encoding: A64 A32 T32
```
At the top is the overall v8 instruction set archicture. Second are the
two modes, defined by bitwidth but differing in other semantics too, and
buttom are the encodings, (hopefully?) isomorphic if they encode the
same mode.
The 32 bit encodings are mostly backwards compatible with previous
non-Thumb and Thumb encodings, and if so we can pun the mode names to
instead mean "sets of compatable or isomorphic encodings", and then
voilà we have nice names for 32-bit and 64-bit arm instruction sets
which do not use the word ARM so as to not confused either laymen or
experienced ARM packages.
[1]: https://developer.arm.com/products/architecture/a-profile
This obsoletes two of the included patches, one of them RISC-V specific,
since they've been picked up by upstream.
This build has been confirmed as being able to build and run an (extremely
recent) RISC-V Fedora 28 Rawhide image, available from:
https://fedorapeople.org/groups/risc-v/disk-images/
Signed-off-by: Austin Seipp <aseipp@pobox.com>
* $out/bin/qemu-kvm should point to qemu-system-aarch64 on aarch64, libvirt expect it
* makeWrapper codes are separated as some architectures might require additional command flags (https://github.com/NixOS/nixpkgs/issues/31606#issuecomment-349675127)
* x86_64-on-i686 is not a native emulation and not supported by KVM, so it is removed from the list
