Re: [PATCH v6 3/7] qemu: add support for iOS host

[Peter Maydell]

On Tue, 5 Jan 2021 at 02:25, Joelle van Dyne <j@getutm.app> wrote:
>
> This introduces support for building for iOS hosts. When the correct Xcode
> toolchain is used, iOS host will be detected automatically.
>
> * block: disable features not supported by iOS sandbox
> * slirp: disable SMB features for iOS
> * osdep: disable system() calls for iOS

> +``ucontext`` support is broken on iOS. The implementation from 
> ``libucontext``
> +is used instead.

Just a note since it came up in another thread today, but
looking at libucontext its aarch64 backend doesn't handle
the floating point registers. I think if the *context
routines don't save/restore the callee-saves fp regs
(v8-v15, FPCR) then it's liable to result in tricky-to-track
down bugs where some kept-in-a-callee-saves-fp-register data
from a function further up the callstack gets corrupted, depending
on what the compiler happens to do. It would be good to work with
the libucontext maintainers to add that functionality.

thanks
-- PMM