Update dos-djgpp.yml

.github/workflows/dos-djgpp.yml

@@ -42,7 +42,7 @@ jobs:
       - name: Setup build environment
         run: |
           sudo apt -y update
-          sudo apt -y install build-essential cmake wget 7zip git flex libfl-dev nasm libslang2-dev pkg-config libslang2-modules gcc-multilib dosbox
+          sudo apt -y install build-essential cmake wget 7zip git flex libfl-dev nasm libslang2-dev pkg-config libslang2-modules gcc-multilib dosbox tree
 
       - name: Download and Setup DJGPP Toolchain
         run: |
@@ -91,6 +91,14 @@ jobs:
           pushd build
           cmake ../ -D DJGPP_WATT32=${WATT_ROOT}/lib/libwatt.a -D CMAKE_FIND_ROOT_PATH=${CMAKE_FIND_ROOT_PATH}
           make
+          
+      - name: Implement stub
+        run: |
+          
+          wget https://web.archive.org/web/20250308092209/https://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/util/system/cwsdpmi/csdpmi7b.zip -O CSDPMI7B.ZIP
+          7z e CSDPMI7B.ZIP bin/CWSDSTUB.EXE
+          i586-pc-msdosdjgpp-exe2coff build/umskt.exe
+          cat CWSDSTUB.EXE umskt > umskt.exe
 
       - name: Setup DOSBox test environment
         run: |