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-rw-r--r--pu1/pu.c419
1 files changed, 419 insertions, 0 deletions
diff --git a/pu1/pu.c b/pu1/pu.c
new file mode 100644
index 0000000..f182e65
--- /dev/null
+++ b/pu1/pu.c
@@ -0,0 +1,419 @@
+#define _XOPEN_SOURCE 700
+#include <SDL2/SDL.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#pragma clang diagnostic ignored "-Wreturn-type"
+#pragma clang diagnostic ignored "-Wc23-extensions"
+#pragma clang diagnostic ignored "-Wnull-character"
+#pragma clang diagnostic ignored "-Wimplicit-int"
+#pragma clang diagnostic ignored "-Wparentheses"
+#pragma clang diagnostic ignored "-Wempty-body"
+
+// NOTE: If you want the CPU to crash when there is an illegal instruction, replace the useless "4"
+// in the code with "__builtin_trap()".
+// clang-format off
+#define S 1<<20
+#define H !--c?
+#define J while
+m[S],c,a;pu(){J(c=m[m[7]++])H*m=m[m[7]++]:c--<9?!a?m[c]=*m:0:8>(c-=8)?*m=m[c]:!(c-=8)?m[m[1]]=*m:H*m=a:H a+=*m:H a-=*m:H a=!a:H a=0:4;}
+// clang-format on
+
+// a is acc
+// first 8 memory bytes are registers actually
+// c is pc, read from m[7]
+
+// --- opcodes ---
+// 0 = halt DONE
+// 1 = const in r0 DONE
+// 2...9 = r0 in rX (only if acc is zero) DONE
+// 10...17 = rX in r0 DONE
+// 18 = r0 in m[r1] DONE
+// 19 = acc in r0 DONE
+// 20 = acc += r0 DONE
+// 21 = acc -= r0 DONE
+// 22 = acc = !acc DONE
+// 23 = acc = 0 DONE
+// for ops 2..9 and 10..17 it basically works like this: 2 handles r0, 3 r1, 4 r2, etc. 10 handles
+// r0, 11 r1, 12 r2 and so on.
+
+// compiler!
+// the switch skips whitespace. then, the beautiful loop thingymajigy emits bytecode.
+
+// clang-format off
+#define W case
+#define Q goto M;
+char R[]={
+#embed "t"
+};K;char*Y[1<<9];void*as(char*I,int*O){char*V;J(K=*I){V=R;switch(K){W 32:W 10:W 9:I++;Q;W 35:J(*++I!=10);Q W 40:I++;K=strtol(I,&I,10);Y[K]=I;J(*I++!=41);Q W 41:return O;W 64:O=as(Y[strtol(++I,&I,10)],O);if((long)O<0)return O;Q W 39:*O++=1;I++;*O++=*I++;Q}strncmp("con",I,3)?:({*O++=1,*O++=strtol(I+=3,&I,10);Q});J(*V)V+=3,(strncmp(V-3,I,3)?:({*O++=*V;I+=3;Q})),V+=2;return(char*)-(long)I;M:}return 0;}
+// clang-format on
+
+#undef Q
+#undef H
+#undef W
+#undef S
+#undef J
+
+#ifndef __WRAPPER
+
+SDL_Window *window = NULL;
+SDL_Renderer *renderer = NULL;
+
+// runs pu until exit code != 2,
+// that exit code is an interrupt for talking to the emulated hardware
+emu() {
+ while (1) {
+ pu();
+ int e_code = m[ 0 ];
+
+ // Poll SDL events to handle window close, etc.
+ SDL_Event event;
+ while (SDL_PollEvent(&event)) {
+ if (event.type == SDL_QUIT) {
+ if (renderer) SDL_DestroyRenderer(renderer);
+ if (window) SDL_DestroyWindow(window);
+ SDL_Quit();
+ return 0;
+ }
+ // Additional event handling can be added here if needed.
+ }
+
+ if (e_code != 2) {
+ if (renderer) SDL_DestroyRenderer(renderer);
+ if (window) SDL_DestroyWindow(window);
+ SDL_Quit();
+ return e_code;
+ }
+
+ // handle hardware interrupts
+ int int_code = m[ 1 ];
+
+ // 0: output string
+ if (int_code == 0) {
+ int ptr = m[ 2 ];
+ int size = m[ 3 ], i = 0;
+
+ for (; i < size; i++) putchar(m[ ptr++ ]);
+ while (size--) putchar(m[ ptr++ ]);
+ }
+
+ // 1: input character
+ else if (int_code == 1) {
+ m[ 2 ] = getchar();
+ }
+
+ // 2: graphics operations via SDL2
+ else if (int_code == 2) {
+ int gfx_op = m[ 2 ];
+ switch (gfx_op) {
+ case 0: // Initialize window (parameters: width in m[3], height in m[4])
+ {
+ int width = m[ 3 ];
+ int height = m[ 4 ];
+ if (SDL_Init(SDL_INIT_VIDEO) < 0) {
+ fprintf(stderr, "SDL_Init failed: %s\n", SDL_GetError());
+ m[ 0 ] = 1; // Set e_code to indicate error
+ break;
+ }
+ window = SDL_CreateWindow(
+ "PU VM Graphics",
+ SDL_WINDOWPOS_CENTERED,
+ SDL_WINDOWPOS_CENTERED,
+ width,
+ height,
+ 0);
+ if (!window) {
+ fprintf(stderr, "SDL_CreateWindow failed: %s\n", SDL_GetError());
+ m[ 0 ] = 1; // Set e_code to indicate error
+ break;
+ }
+ renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
+ if (!renderer) {
+ fprintf(stderr, "SDL_CreateRenderer failed: %s\n", SDL_GetError());
+ m[ 0 ] = 1; // Set e_code to indicate error
+ break;
+ }
+
+ break;
+ }
+ case 1: // Set draw color (parameters: r in m[3], g in m[4], b in m[5], a in m[6])
+ {
+ Uint8 r = (Uint8) m[ 3 ];
+ Uint8 g = (Uint8) m[ 4 ];
+ Uint8 b = (Uint8) m[ 5 ];
+ Uint8 a = (Uint8) m[ 6 ];
+ SDL_SetRenderDrawColor(renderer, r, g, b, a);
+ break;
+ }
+ case 2: // Clear screen
+ SDL_RenderClear(renderer);
+ break;
+ case 3: // Present (flip buffers)
+ SDL_RenderPresent(renderer);
+ break;
+ case 4: // Draw point (parameters: x in m[3], y in m[4])
+ {
+ int x = m[ 3 ];
+ int y = m[ 4 ];
+ SDL_RenderDrawPoint(renderer, x, y);
+ break;
+ }
+ case 5: // Draw line (parameters: x1 in m[3], y1 in m[4], x2 in m[5], y2 in m[6])
+ {
+ int x1 = m[ 3 ];
+ int y1 = m[ 4 ];
+ int x2 = m[ 5 ];
+ int y2 = m[ 6 ];
+ SDL_RenderDrawLine(renderer, x1, y1, x2, y2);
+ break;
+ }
+ case 6: // Fill rectangle (parameters: x in m[3], y in m[4], w in m[5], h in m[6])
+ {
+ int x = m[ 3 ];
+ int y = m[ 4 ];
+ int w = m[ 5 ];
+ int h = m[ 6 ];
+ SDL_Rect rect = { x, y, w, h };
+ SDL_RenderFillRect(renderer, &rect);
+ break;
+ }
+ case 7: // Draw rectangle outline (parameters: x in m[3], y in m[4], w in m[5], h in
+ // m[6])
+ {
+ int x = m[ 3 ];
+ int y = m[ 4 ];
+ int w = m[ 5 ];
+ int h = m[ 6 ];
+ SDL_Rect rect = { x, y, w, h };
+ SDL_RenderDrawRect(renderer, &rect);
+ break;
+ }
+ case 8: // Quit graphics
+ if (renderer) SDL_DestroyRenderer(renderer);
+ if (window) SDL_DestroyWindow(window);
+ SDL_Quit();
+ renderer = NULL;
+ window = NULL;
+ break;
+ default:
+ // Unknown graphics operation; ignored for simplicity.
+ break;
+ }
+ }
+
+ else {
+ // unknown interrupt. what to do?
+ }
+
+ m[ 0 ] = 0;
+ }
+}
+
+char R_backup[] = "hlt\0 ar1\2 ar2\3 ar3\4 ar4\5 ar5\6 ar6\7 ar7\x8 ar8\x9 r1a\xA r2a\xB r3a\xC "
+ "r4a\xD r5a\xE r6a\xF r7a\20 r8a\21 mem\22 aca\23 add\24 sub\25 not\26 clr\27";
+
+error_debug(char *fail_point, char *code, int sz) {
+ if ((long) fail_point >= 0) return;
+
+ fail_point = (char *) -(long) fail_point;
+ int error_pos = (int) (fail_point - code);
+ int i;
+
+ int line = 1, col = 1;
+ for (i = 0; i < error_pos && i < sz; i++) {
+ if (code[ i ] == '\n') {
+ line++;
+ col = 1;
+ } else {
+ col++;
+ }
+ }
+
+ fprintf(
+ stderr,
+ "\x1b[1m\x1b[31merror:\x1b[0m "
+ "\x1b[1massembly failed\x1b[0m "
+ "at \x1b[36mline %d\x1b[0m, \x1b[36mcolumn %d\x1b[0m "
+ "(\x1b[33mposition %d\x1b[0m):\n",
+ line,
+ col,
+ error_pos);
+
+ int line_start = error_pos;
+ while (line_start > 0 && code[ line_start - 1 ] != '\n') { line_start--; }
+
+ int line_end = error_pos;
+ while (line_end < sz && code[ line_end ] != '\n' && code[ line_end ] != '\0') { line_end++; }
+
+ fprintf(stderr, " \x1b[1m");
+ for (i = line_start; i < line_end; i++) { fputc(code[ i ], stderr); }
+ fprintf(stderr, "\x1b[0m\n");
+
+ fprintf(stderr, " ");
+ for (i = line_start; i < error_pos; i++) { fputc((code[ i ] == '\t') ? '\t' : ' ', stderr); }
+ fprintf(stderr, "\x1b[1m\x1b[31m^\x1b[0m \x1b[90mparsing stopped here\x1b[0m\n");
+}
+
+main(int argc, char **argv) {
+ if (access("t", F_OK)) {
+ // patch the instruction table incase you removed it.
+ printf("you've deleted `t`! i'll write it again for you.\n\n");
+ FILE *fp = fopen("t", "w+");
+ fwrite(R_backup, 1, sizeof(R_backup), fp);
+ fclose(fp);
+ memcpy(R, R_backup, sizeof(R_backup));
+ }
+
+ if (argc == 1) {
+ printf(
+ "Usage:\n"
+ " %s run <filename>: Execute a file\n"
+ " %s repl: Open in REPL mode",
+ argv[ 0 ],
+ argv[ 0 ]);
+ exit(1);
+ }
+
+ if (argc == 2 && !strcmp(argv[ 1 ], "repl")) {
+ printf("\npu repl\n"
+ "| code is inserted at address 1024\n"
+ "| submit RUN to execute the code.\n"
+ "| submit CLEAR to erase history.\n"
+ "| submit SAVE to write contents to repl.pu\n"
+ "| submit LOAD to fetch contents from repl.pu\n"
+ "\n");
+
+ char *code = malloc(1);
+ *code = '\n';
+ size_t size = 0;
+
+ while (1) {
+ printf("%li > ", size);
+ char *line;
+ size_t _len;
+ size_t len = getline(&line, &_len, stdin);
+
+ if (len == 1) continue;
+
+ if (len == 4 && strncmp(line, "run", 3) == 0) {
+ memset(m, 0, 8);
+ m[ 7 ] = 1024;
+ emu();
+ int i;
+ for (i = 0; i < 16; i++) printf("%i ", m[ 1024 + i ]);
+ printf("\n\n");
+ continue;
+ }
+
+ if (len == 5 && strncmp(line, "save", 4) == 0) {
+ FILE *fd = fopen("repl.pu", "w+");
+ fwrite(code, 1, size, fd);
+ fclose(fd);
+ printf("saved %li bytes.\n", size);
+
+ continue;
+ }
+
+ if (len == 5 && strncmp(line, "load", 4) == 0) {
+ FILE *fp = fopen("repl.pu", "r");
+ fseek(fp, 0, SEEK_END);
+ int sz = ftell(fp);
+ rewind(fp);
+ char *saved = malloc(sz + 1);
+ fread(saved, 1, sz, fp);
+ saved[ sz ] = 0;
+ fclose(fp);
+
+ free(code);
+ code = saved;
+ size = sz;
+ printf("loaded %i bytes.\n", sz);
+
+ goto SKIP_STRAIGHT;
+ }
+
+ if (len == 6 && strncmp(line, "clear", 5) == 0) {
+ printf("-- code cleared\n");
+ free(code);
+ code = malloc(1);
+ size = 0;
+ continue;
+ }
+
+ if (len == 7 && strncmp(line, "status", 6) == 0) {
+ printf(
+ "\nregisters\n"
+ "r1: %i r2: %i\n"
+ "r3: %i r4: %i\n"
+ "r5: %i r6: %i\n"
+ "r7: %i pc: %i\n\n",
+ m[ 0 ],
+ m[ 1 ],
+ m[ 2 ],
+ m[ 3 ],
+ m[ 4 ],
+ m[ 5 ],
+ m[ 6 ],
+ m[ 7 ]);
+
+ continue;
+ }
+
+ char *old_code = malloc(size);
+ memcpy(old_code, code, size);
+
+ code = realloc(code, size += len);
+ memcpy(&code[ size - len ], line, len);
+
+ SKIP_STRAIGHT:
+
+ char *exit_code = as(code, &m[ 1024 ]);
+
+ if (exit_code != 0) {
+ printf("\n");
+ error_debug(exit_code, code, size);
+ printf("\n");
+
+ free(code);
+ code = old_code;
+ size -= len;
+ continue;
+ }
+
+ free(old_code);
+ }
+
+ exit(0);
+ }
+
+ if (argc == 3 && strcmp(argv[ 1 ], "run") != 0) {
+ printf("Invalid mode - Only supported modes are 'run' and 'repl'\n");
+ return;
+ }
+
+ // read code
+ FILE *fp = fopen(argv[ 2 ], "r");
+ fseek(fp, 0, SEEK_END);
+ int sz = ftell(fp);
+ rewind(fp);
+ char code[ sz + 1 ];
+ fread(code, 1, sz, fp);
+ code[ sz ] = 0;
+ fclose(fp);
+
+ // set pc
+ m[ 7 ] = 1024;
+ // assemble
+ char *fail_point = as(code, &m[ 1024 ]);
+
+ if (fail_point != 0) {
+ error_debug(fail_point, code, sz);
+ return;
+ }
+
+ // run emulation
+ emu();
+}
+#endif \ No newline at end of file
generated by cgit v1.2.3 (git 2.39.1) at 2026-10-27 16:58:15 +0000