Re: problem using gcc-core for compile qemu

[Eliot Moss <moss@cs.umass.edu>]

On 1/8/2021 3:42 AM, Arthur Norman via Cygwin wrote:
 >> I can't use virtualbx because what I need is to emulate
 >> the aarch64 architecture, I don't want to use binaries compiled by
 >> others, one of the reasons is that those binaries don't include sd-card emulation support...
 > This is perhaps an off-topic response as regards compiling things on cygwin, but some while back I
 > found a range of sets of instructions for setting up aarch64 emulation in qemu. When I had any
 > issues running on Windows I just used virtualbox to give myself an x86_64 Linux world and installed
 > qemu there. And after a while I could buy a Raspberry pi with a 64-bit cpu and use that, so these
 > days working with aarch64 (and an SD card) works best for me on an rpi4 not via emulation. But to
 > find people who have worked on adapting and setting up qemu to support aarch64 with an SD card you
 > might find it useful to follow the footsteps of those who were working towards rpi 64-bit support?
 > And I like and use cygwin for most of what I do, but when something I want to do is better supported
 > by Linux then setting up an Ubuntu via virtualbox uses some disc space but does not add much
 > overhead on my main W10 machine and lets me build, test and debug there because following a path
 > that is already well trodden is often easiest!
 > Arthur

I want to second some of that.  My research regularly involves development for
ARM targets (more commonly 32 bit, but also 64).  I happen to use VirtualBox
and there cross-compile from x86 to ARM.  This works for building even a whole
OS from scratch.  After that I am using gem5, not qemu, but the principle
would be the same.  I also spent less than $100 to set myself up with a
Raspberry Pi and SD card.  (I still need gem5 because I am emulating some
additional hardware that does not physically exist (yet, anyway).)

If you need to cross-compile to an ARM target, you could download the Cygwin
gcc package source and build the cross compiler to aarch 64, along with the
other cross tools from bin utils (I am thinking of nm, objdump, etc.).  Then
you can build binaries for ARM using Cygwin, if you like.  I am not aware of
already existing Cygwin packages for ARM targets, but somebody may have built
them.

One advantage of VirtualBox is that Ubuntu packages fo cross compiling to ARM
already exist so I just install and run them.

Best wishes - Eliot Moss