add RISC5 interrupt implementation

.github/workflows/build-and-test.yml

@@ -0,0 +1,41 @@
+name: Build and Test
+on: [push]
+jobs:
+  Ubuntu-build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Install Dependencies
+        run: |
+          sudo add-apt-repository -y "deb http://archive.ubuntu.com/ubuntu `lsb_release -sc` main universe restricted multiverse"
+          sudo apt-get update -y -qq
+          sudo apt-get install libsdl2-dev
+
+      - name: Build
+        run: |
+          make
+
+      - name: Test
+        run: |
+          ls -alh ./risc
+
+  MacOS-build:
+    runs-on: macOS-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Install Dependencies
+        run: | 
+          brew install SDL2
+
+      - name: Build
+        run: |
+          make
+
+      - name: Test
+        run: |
+          ls -alh ./risc      
+

.github/workflows/release.yml

@@ -0,0 +1,99 @@
+name: Release
+
+on:
+  # Trigger the workflow on the new 'v*' tag created
+  push:
+    tags:
+      - "v*"
+
+jobs:
+  create_release:
+    name: Create Github Release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v2
+
+      - name: Create Release
+        id: create_release
+        uses: actions/[email protected]
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: Release ${{ github.ref }}
+          draft: true
+          prerelease: false
+
+      - name: Output Release URL File
+        run: echo "${{ steps.create_release.outputs.upload_url }}" > release_url.txt
+      - name: Save Release URL File for publish
+        uses: actions/upload-artifact@v1
+        with:
+          name: release_url
+          path: release_url.txt
+
+  build_artifact:
+    needs: [create_release]
+    name: ${{ matrix.os }}-build-${{ github.ref }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macOS-latest]
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Set tag name
+        uses: olegtarasov/[email protected]
+        id: tag
+        with:
+          tagRegex: "v(.*)"
+          tagRegexGroup: 1
+
+      - name: Build binary
+        run: |
+          mkdir dist
+
+      - if: matrix.os == 'ubuntu-latest'
+        name: Install ubuntu dependencies and build
+        run: |
+          sudo add-apt-repository -y "deb http://archive.ubuntu.com/ubuntu `lsb_release -sc` main universe restricted multiverse"
+          sudo apt-get update -y -qq
+          sudo apt-get install libsdl2-dev
+          make
+          cp ./risc dist/risc-ubuntu-latest
+
+      - if: matrix.os == 'macOS-latest'
+        name: Install macOS dependencies and build
+        run: | 
+          brew install SDL2
+          make
+          cp ./risc dist/risc-macOS-latest
+
+      - name: Load Release URL File from release job
+        uses: actions/download-artifact@v1
+        with:
+          name: release_url
+
+      - name: Set binary path name
+        run: echo "BINARY_PATH=./dist/risc-${{ matrix.os }}" >> $GITHUB_ENV
+
+      - name: Get Release File Name & Upload URL
+        id: get_release_info
+        run: |
+          echo "::set-output name=upload_url::$(cat release_url/release_url.txt)"
+
+      - name: Upload Release Asset
+        id: upload-release-asset
+        uses: actions/[email protected]
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.get_release_info.outputs.upload_url }}
+          asset_path: ${{ env.BINARY_PATH }}
+          asset_name: risc-on-${{ runner.os }}
+          asset_content_type: application/octet-stream
+
+

README.md

@@ -1,4 +1,12 @@
-# Oberon RISC Emulator
+# Oberon RISC Emulator Integrated Oberon Fork
+
+Forked from [Peter De Wachter's RISC emulator in C](https://github.com/pdewacht/oberon-risc-emu) with miscelaneous features added
+
+* CAUTION: More features are not always better features!
+
+Latest risc binary for Ubuntu: [risc-on-Linux](https://github.com/io-core/oberon-risc-emu/releases/download/v2021.9.4/risc-on-Linux) (Requires SDL2 installed via apt)
+
+Latest risc binary for macOS: [risc-on-macOS](https://github.com/io-core/oberon-risc-emu/releases/download/v2021.9.4/risc-on-macOS) (Requires SDL2 installed via homebrew)
 
 This is an emulator for the Oberon RISC machine. For more information,
 [see Niklaus Wirth's site](https://www.inf.ethz.ch/personal/wirth/). For

src/Makefile.vc

@@ -0,0 +1,41 @@
+CC = cl
+CFLAGS = -D_WIN32 -Zi -W4 -WX -D_CRT_SECURE_NO_WARNINGS -MD \
+		-DSTATIC_BUFSIZ= -DS_IRUSR=0 -DS_IWUSR=0 \
+		-wd4146  -wd4100 -wd4996 -nologo
+
+
+
+
+RISC_CFLAGS = $(CFLAGS)  
+
+RISC_SOURCE = \
+	sdl-main.c \
+	sdl-ps2.c sdl-ps2.h \
+	risc.c risc.h risc-boot.inc \
+	risc-fp.c risc-fp.h \
+	disk.c disk.h \
+	pclink.c pclink.h \
+	raw-serial.c raw-serial.h \
+	sdl-clipboard.c sdl-clipboard.h
+
+all: risc.exe
+
+XOBJS:= $(patsubst %.c,%.obj,$(filter %.c, $(RISC_SOURCE)) )
+
+OBJS:= $(patsubst %.c,%.obj,$(filter %.c, $(RISC_SOURCE)) )
+
+%.obj:%.c
+	$(CC) -c  $(RISC_CFLAGS) $< -Fo$@
+
+risc.exe:$(RISC_SOURCE)
+	$(CC) -c $(RISC_CFLAGS) sdl-main.c
+	dir
+	dir src
+
+foo:
+	link -debug:full $(OBJS) sdl2main.lib  sdl2.lib getopt.lib -SUBSYSTEM:WINDOWS -out:$@ 
+
+clean:
+	-del /s *.obj 
+	-del *.exe
+	-del *.pdb

src/risc.c

@@ -30,11 +30,16 @@ struct RISC {
   uint32_t PC;
   uint32_t R[16];
   uint32_t H;
-  bool     Z, N, C, V;
+  uint32_t SPC;                 // SPC: Saved PC
+  bool     SZ, SN, SC, SV;      //    : Saved Condition Codes
+  bool     Z, N, C, V, I, E, P; //   I: Interrupt mode
+                                //   E: Interrupts enabled
+                                //   P: Interrupt pending
 
   uint32_t mem_size;
   uint32_t display_start;
 
+  uint32_t shutdown;
   uint32_t progress;
   uint32_t current_tick;
   uint32_t mouse;
@@ -158,22 +163,37 @@ void risc_set_switches(struct RISC *risc, int switches) {
 }
 
 void risc_reset(struct RISC *risc) {
+  risc->shutdown = 0;
   risc->PC = ROMStart/4;
 }
 
-void risc_run(struct RISC *risc, int cycles) {
+void risc_trigger_interrupt(struct RISC *risc) {
+  risc->P = true;
+}
+
+int risc_run(struct RISC *risc, int cycles) {
   risc->progress = 20;
   // The progress value is used to detect that the RISC cpu is busy
   // waiting on the millisecond counter or on the keyboard ready
   // bit. In that case it's better to just pause emulation until the
   // next frame.
-  for (int i = 0; i < cycles && risc->progress; i++) {
+  for (int i = 0; i < cycles && risc->progress && (risc->shutdown == 0); i++) {
     risc_single_step(risc);
   }
+  return risc->shutdown;
 }
 
 static void risc_single_step(struct RISC *risc) {
   uint32_t ir;
+  if (risc->P && risc->E && ! risc->I ) {
+    risc->SPC = risc->PC;
+    risc->SZ = risc->Z;
+    risc->SN = risc->N;
+    risc->SC = risc->C;
+    risc->SV = risc->V;
+    risc->I = true;
+    risc->PC = 1;
+  }
   if (risc->PC < risc->mem_size / 4) {
     ir = risc->RAM[risc->PC];
   } else if (risc->PC >= ROMStart/4 && risc->PC < ROMStart/4 + ROMWords) {
@@ -359,7 +379,23 @@ static void risc_single_step(struct RISC *risc) {
       case 4: t ^= risc->C | risc->Z; break;
       case 5: t ^= risc->N ^ risc->V; break;
       case 6: t ^= (risc->N ^ risc->V) | risc->Z; break;
-      case 7: t ^= true; break;
+      case 7: t ^= true; 
+              if (((ir & ubit) == 0) && ((ir & 0x00000010) == 0x10) && risc->I) { // IRET
+                 risc->PC = risc->SPC;
+                 risc->Z = risc->SZ;
+                 risc->N = risc->SN;
+                 risc->C = risc->SC;
+                 risc->V = risc->SV;
+                 risc->I = false;
+                 risc->P = false;
+                 return;
+              }else{
+                if (((ir & ubit) == 0) && ((ir & 0x00000020) == 0x20)) { // STI and CLI
+                   risc->E = (ir & 1) == 1 ? true: false;
+                   return;
+                }
+              }
+              break;
       default: abort();  // unreachable
     }
     if (t) {
@@ -551,6 +587,13 @@ static void risc_store_io(struct RISC *risc, uint32_t address, uint32_t value) {
       risc->spi_selected = value & 3;
       break;
     }
+    case 32: {
+      // halt with value
+      // SDL_Quit();
+      //exit(value);
+      risc->shutdown = 1;
+      break;
+    }
     case 40: {
       // Clipboard control
       if (risc->clipboard) {

src/risc.h

@@ -24,7 +24,8 @@ void risc_set_clipboard(struct RISC *risc, const struct RISC_Clipboard *clipboar
 void risc_set_switches(struct RISC *risc, int switches);
 
 void risc_reset(struct RISC *risc);
-void risc_run(struct RISC *risc, int cycles);
+void risc_trigger_interrupt(struct RISC *risc); 
+int risc_run(struct RISC *risc, int cycles);
 void risc_set_time(struct RISC *risc, uint32_t tick);
 void risc_mouse_moved(struct RISC *risc, int mouse_x, int mouse_y);
 void risc_mouse_button(struct RISC *risc, int button, bool down);

src/sdl-main.c

@@ -17,6 +17,7 @@
 
 #define CPU_HZ 25000000
 #define FPS 60
+#define MSPF 1000/FPS
 
 static uint32_t BLACK = 0x657b83, WHITE = 0xfdf6e3;
 //static uint32_t BLACK = 0x000000, WHITE = 0xFFFFFF;
@@ -62,6 +63,7 @@ struct KeyMapping key_map[] = {
 };
 
 static struct option long_options[] = {
+  { "version",          no_argument,       NULL, 'V' },
   { "zoom",             required_argument, NULL, 'z' },
   { "fullscreen",       no_argument,       NULL, 'f' },
   { "leds",             no_argument,       NULL, 'L' },
@@ -86,6 +88,7 @@ static void usage() {
   puts("Usage: risc [OPTIONS...] DISK-IMAGE\n"
        "\n"
        "Options:\n"
+       "  --version             Print the version of the emulator\n"
        "  --fullscreen          Start the emulator in full screen mode\n"
        "  --zoom REAL           Scale the display in windowed mode\n"
        "  --leds                Log LED state on stdout\n"
@@ -120,7 +123,7 @@ int main (int argc, char *argv[]) {
   bool boot_from_serial = false;
 
   int opt;
-  while ((opt = getopt_long(argc, argv, "z:fLm:s:I:O:S", long_options, NULL)) != -1) {
+  while ((opt = getopt_long(argc, argv, "z:fLmV:s:I:O:S", long_options, NULL)) != -1) {
     switch (opt) {
       case 'z': {
         double x = strtod(optarg, 0);
@@ -129,6 +132,12 @@ int main (int argc, char *argv[]) {
         }
         break;
       }
+      case 'V': {
+        fullscreen = true;
+	printf("2021.8.31\n");
+	exit(0);
+        break;
+      }
       case 'f': {
         fullscreen = true;
         break;
@@ -334,20 +343,25 @@ int main (int argc, char *argv[]) {
         }
       }
     }
-
+    int sd = 0;
     risc_set_time(risc, frame_start);
-    risc_run(risc, CPU_HZ / FPS);
-
+    for (int i=0; i<MSPF; i++) {
+      sd = risc_run(risc, CPU_HZ / 1000 * MSPF);
+      if(sd == 1){
+	SDL_Quit();
+	exit(0);
+      }
+      uint32_t frame_end = SDL_GetTicks();
+      int delay = frame_start + MSPF - frame_end;
+      if (delay > 0) {
+        SDL_Delay(delay);
+      }
+      risc_trigger_interrupt(risc);
+    }
     update_texture(risc, texture, &risc_rect);
     SDL_RenderClear(renderer);
     SDL_RenderCopy(renderer, texture, &risc_rect, &display_rect);
     SDL_RenderPresent(renderer);
-
-    uint32_t frame_end = SDL_GetTicks();
-    int delay = frame_start + 1000/FPS - frame_end;
-    if (delay > 0) {
-      SDL_Delay(delay);
-    }
   }
   return 0;
 }

tag-and-push-to-github.txt

@@ -0,0 +1,3 @@
+git tag -a v202x.x.xx -m "tag message"
+git push origin v202x.x.xx
+