qemu-system-mipsel freezes for nanoMIPS in the semihosting mode

Host environment

• Operating system: Ubuntu
• OS/kernel version: 20.04.2 LTS (Focal Fossa)
• Architecture: x86_64
• QEMU flavor: qemu-system-mipsel
• QEMU version: 7.0.90 - bad, 6.0.1 - good
• QEMU command line:

  ./qemu-system-mipsel -cpu I7200 -semihosting -nographic -kernel hello.elf

Emulated/Virtualized environment

• Architecture: nanoMIPS

Description of problem

In the current git master branch (SHA: 7b17a1a8) there is a problem with qemu-system-mipsel when trying to execute a simple hello.elf program in the semihosting mode for the nanoMIPS architecture. I.e. after executing the following command the terminal freezes:

  $ ./qemu-system-mipsel -cpu I7200 -semihosting -nographic -kernel hello.elf

hello.elf file is generated using the nanoMIPS GNU Toolchain (https://github.com/MediaTek-Labs/nanomips-gnu-toolchain/releases). The program regularly terminates with QEMU emulator version 6.0.1.