[Qemu-arm] Pipe implementation for Windows Host

[Jiahuan Zhang]

Hi All,

I am using QEMU to emulate an arm-based Linux kernel in Windows host. I want to make the host and guest communciate via a pipe redirected by a serial port.

From the qemu user documentaion, I get

-chardev pipe ,id=id ,path=path

Create a two-way connection to the guest. The behaviour differs slightly between Windows hosts and other hosts:

On Windows, a single duplex pipe will be created at \\.pipe\path.

On other hosts, 2 pipes will be created called path.in and path.out. Data written to path.in will be received by the guest. Data written by the guest can be read from path.out. QEMU will not create these fifos, and requires them to be present.

path forms part of the pipe path as described above. path is required.

I have successfully made a serial-pipe implementation for the communciation between Linux guest and Linux host by -serial pipe:/temp/serial. The two pipes are created by mkfifo.

But I have no idea about any shortcut to create fifo in windows. I am running qemu via msys64. There is a mkfifo command. However, it just give me a .lnk file, and qemu complains when I use the pipe. See below. So my question is how to create a pipe for Windows host pipe implementation.

Regards,

Jiahuan

 MINGW64 ~/test

$ mkfifo pipe

 MINGW64 ~/test

$ ls -al pipe

prw-rw-rw- 1 qzj Domain Users 0 Jan 16 17:22 pipe

 MINGW64 ~/test

$ ~/qemu/build/arm-softmmu/qemu-system-arm.exe -M versatilepb -kernel test.bin -nographic -serial pipe:/tmp/serial5

QEMU 2.8.50 monitor - type 'help' for more information

(qemu) C:\msys64\home\qemu\build\arm-softmmu\qemu-system-arm.exe: -serial pipe;C:\msys64\tmp\serial5.lnk: could not conect serial device to character backend 'pipe;C:\msys64\tmp\serial5.lnk'