mps2_an521: no input to shell from Windows qemu host

[sw]

Describe the bug
Trying to run a sample with shell functionality and have it work in an emulated ARM machine on a Windows host.
The sample runs and prints the shell prompt, but no input from keyboard is possible.

To Reproduce
Run in Windows command prompt (cmd):

west init
west update
set "GNUARMEMB_TOOLCHAIN_PATH=%ProgramFiles(x86)%\GNU Arm Embedded Toolchain\9 2020-q2-update"
set ZEPHYR_TOOLCHAIN_VARIANT=gnuarmemb
cd zephyr
west build -b mps2_an521 -t run samples\subsys\shell\shell_module -- -DQEMU="%ProgramFiles%\qemu\qemu-system-arm.exe"

Expected behavior
I expect to be able to enter shell commands and have them executed.

Impact
Prevents manual use of shell for testing/dev purposes

Logs and console output

C:\work\hydra\qemu\zephyr>west build -b mps2_an521 -t run samples\subsys\shell\shell_module -- -DQEMU="%ProgramFiles%\qemu\qemu-system-arm.exe"
-- west build: generating a build system
Including boilerplate (Zephyr base (cached)): C:/work/hydra/qemu/zephyr/cmake/app/boilerplate.cmake
-- Application: C:/work/hydra/qemu/zephyr/samples/subsys/shell/shell_module
-- Zephyr version: 2.4.99 (C:/work/hydra/qemu/zephyr)
-- Found west (found suitable version "0.8.0", minimum required is "0.7.1")
-- Board: mps2_an521
-- Cache files will be written to: C:\Users\walter\AppData\Local/.cache/zephyr
-- Found dtc: C:/ProgramData/chocolatey/bin/dtc.exe (found suitable version "1.4.7", minimum required is "1.4.6")
-- Found toolchain: gnuarmemb (C:/Program Files (x86)/GNU Arm Embedded Toolchain/9 2020-q2-update)
-- Found BOARD.dts: C:/work/hydra/qemu/zephyr/boards/arm/mps2_an521/mps2_an521.dts
-- Generated zephyr.dts: C:/work/hydra/qemu/zephyr/build/zephyr/zephyr.dts
-- Generated devicetree_unfixed.h: C:/work/hydra/qemu/zephyr/build/zephyr/include/generated/devicetree_unfixed.h
Parsing C:/work/hydra/qemu/zephyr/samples/subsys/shell/shell_module/Kconfig
Loaded configuration 'C:/work/hydra/qemu/zephyr/build/zephyr/.config'
No change to configuration in 'C:/work/hydra/qemu/zephyr/build/zephyr/.config'
No change to Kconfig header in 'C:/work/hydra/qemu/zephyr/build/zephyr/include/generated/autoconf.h'
-- Configuring done
-- Generating done
-- Build files have been written to: C:/work/hydra/qemu/zephyr/build
-- west build: running target run
[121/126] Linking C executable zephyr\zephyr_prebuilt.elf
Memory region         Used Size  Region Size  %age Used
           FLASH:       54520 B       224 MB      0.02%
            SRAM:       11536 B        16 MB      0.07%
        IDT_LIST:         200 B         2 KB      9.77%
[125/126] To exit from QEMU enter: 'CTRL+a, x'[QEMU] CPU: cortex-m33
C:\Program Files\qemu\qemu-system-arm.exe: warning: nic lan9118.0 has no peer


uart:~$

Environment (please complete the following information):
Windows 10
QEMU version 5.1.92 (v5.2.0-rc2-11843-gf571c4ffb5-dirty)

Additional context
What's the correct way of specifying the Qemu path? Setting the QEMU_BIN_PATH environment variable doesn't seem to work.

We are using the board mps2_an521 because that seems to be the only emulated board with a Cortex-M33 processor. We would really like to emulate an nRF5340.

[sw]

cmake/emu/qemu.cmake uses find_program to find QEMU, but doesn't specify the .exe suffix. I suspect that is why setting the QEMU_BIN_PATH env variable doesn't work.

After changing line 17 as follows, setting QEMU_BIN_PATH will work:

  NAMES qemu-system-${QEMU_binary_suffix} qemu-system-${QEMU_binary_suffix}.exe

[sw]

Serial input is working with board qemu_cortex_m3, so this may be a problem with the uart_cmsdk_apb driver not working properly in qemu

[nashif]

FFIW this is not related to Windows.