polmon: add kopy and split launch into load+run

src/polmon.cc

@@ -164,34 +164,41 @@ uint16_t __readfile__(const char* name, uint16_t addr) {
     return ret;
 }
 
-uint16_t LaunchFile(const char* name, uint8_t len, uint8_t argc,
+uint16_t LoadFile(const char* name, uint8_t len, uint16_t seg) {
-                    uint16_t* argv) {
-    constexpr uint16_t kSegment = 0x200;
     constexpr uint16_t kAddress = 0x100;
-    constexpr uint16_t kHeaderAddress = (kSegment << 4);
-    constexpr uint16_t kFlatAddress = (kSegment << 4) + kAddress;
-    constexpr uint16_t kArgvAddress = 0x0004;
     // trampoline:
     //      call 0x100
     //      retf
     // XXX: if you change kAddress, the trampoline needs to be updated
     constexpr uint8_t kTrampoline[] = {0xe8, 0xfd, 0x00, 0xcb};
 
+    uint16_t headeraddr = (seg << 4);
+    uint16_t flataddr = headeraddr + kAddress;
+
     char fatname[11];
     tofatname(name, len, fatname);
 
-    uint16_t r = __readfile__(fatname, kFlatAddress);
+    uint16_t r = __readfile__(fatname, flataddr);
     if (r) {
         memcpy(fatname + 8, "COM", 3);
-        r = __readfile__(fatname, kFlatAddress);
+        r = __readfile__(fatname, flataddr);
     }
     if (r) {
         return r;
     }
 
-    auto* ptr = reinterpret_cast<uint8_t*>(kHeaderAddress);
+    auto* ptr = reinterpret_cast<uint8_t*>(headeraddr);
     memcpy(ptr, kTrampoline, sizeof(kTrampoline));
-    auto* argp = reinterpret_cast<uint16_t*>(kHeaderAddress + kArgvAddress);
+
+    return 0;
+}
+
+uint16_t Exec(uint16_t seg, uint8_t argc, uint16_t* argv) {
+    constexpr uint16_t kAddress = 0x100;
+    constexpr uint16_t kArgvAddress = 0x0004;
+
+    uint16_t headeraddr = (seg << 4);
+    auto* argp = reinterpret_cast<uint16_t*>(headeraddr + kArgvAddress);
     memcpy(argp, argv, argc * 2);
 
     register uint16_t ac asm("ax") = argc;
@@ -205,8 +212,13 @@ uint16_t LaunchFile(const char* name, uint8_t len, uint8_t argc,
                  "xchg %%cx, %%sp   \n\t"
                  "sti               \n\t"
                  "push %%cx         \n\t"
-                 "lcall %2,$0       \n\t"
+                 "push %2           \n\t"
                  "xor %%cx, %%cx    \n\t"
+                 "push %%cx         \n\t"
+                 "mov %%sp, %%bx    \n\t"
+                 "lcall *(%%bx)     \n\t"
+                 "pop %%cx          \n\t"
+                 "pop %%dx          \n\t"
                  "mov %%cx, %%ds    \n\t"
                  "mov %%cx, %%es    \n\t"
                  "cli               \n\t"
@@ -214,7 +226,7 @@ uint16_t LaunchFile(const char* name, uint8_t len, uint8_t argc,
                  "mov %%cx, %%ss    \n\t"
                  "sti"
                  : "+r"(ac), "+r"(av)
-                 : "i"(kSegment), "i"(kAddress)
+                 : "r"(seg), "i"(kAddress)
                  : "bx", "cx", "memory", "cc");
 
     return ac;
@@ -245,13 +257,43 @@ void InstallCtrlBreak() {
     vec[1] = 0;
 }
 
+// j
+// w [u8]*
+// i [u16] [u16]*
+// r str [u16]*
+// k u16 u16 u16
+
+int ReadArgs(const char*& ptr, uint16_t* args, int size) {
+    int nargs = 0;
+    while (*ptr && nargs < size) {
+        if (*ptr == ' ') {
+            ptr += 1;
+            continue;
+        }
+        args[nargs] = ReadUint16(ptr);
+        nargs += 1;
+    }
+    return nargs;
+}
+
+int ReadString(const char*& ptr, const char*& str) {
+    while (*ptr == ' ') {
+        ptr++;
+    }
+    str = ptr;
+    int l;
+    for (l = 0; *ptr && *ptr != ' '; l++, ptr++) {
+    }
+    return l;
+}
+
 bool ParseCommand(const char* buf, uint16_t& cur_addr, uint16_t& cur_seg) {
     bool dump = true;
     for (const char* ptr = buf; *ptr;) {
         if (*ptr == 's') {
-            cur_addr = 0;
             ptr += 1;
-            cur_seg = ReadUint16(ptr);
+            cur_addr = 0;
+            ReadArgs(ptr, &cur_seg, 1);
         } else if (*ptr == '$') {
             __basic__();
         } else if (*ptr == 'j') {
@@ -262,44 +304,27 @@ bool ParseCommand(const char* buf, uint16_t& cur_addr, uint16_t& cur_seg) {
             WriteUint16ln(ret);
         } else if (*ptr == 'i') {
             dump = false;
+            ptr++;
             uint16_t args[8];  // ought to be enough for everybody
-            uint8_t nargs = 0;
+            int nargs = ReadArgs(ptr, args, 8);
-            ptr++;
+            uint16_t fun = args[0];
-            int fun = ReadUint8(ptr) << 8;
+            uint16_t ret = Int80h(fun, nargs - 1, args + 1);
-            fun += ReadUint8(ptr);
-            for (; *ptr && nargs < 8;) {
-                if (*ptr == ' ') {
-                    ptr++;
-                    continue;
-                }
-                args[nargs++] = ReadUint16(ptr);
-            }
-            uint16_t ret = Int80h(fun, nargs, args);
             WriteUint16ln(ret);
         } else if (*ptr == 'l') {
             dump = false;
-            ClearScreen();
             ptr++;
+            const char* fname;
+            int l = ReadString(ptr, fname);
+            uint16_t ret = LoadFile(fname, l, cur_seg);
+            if (ret) {
+                WriteUint16ln(ret);
+            }
         } else if (*ptr == 'r') {
             dump = false;
+            ptr++;
             uint16_t args[8];  // ought to be enough for everybody
-            uint8_t nargs = 0;
+            int nargs = ReadArgs(ptr, args, 8);
-            ptr++;
+            uint16_t ret = Exec(cur_seg, nargs, args);
-            while (*ptr == ' ') {
-                ptr++;
-            }
-            const char* fname = ptr;
-            int l;
-            for (l = 0; *ptr && *ptr != ' '; l++, ptr++) {
-            }
-            for (; *ptr && nargs < 8;) {
-                if (*ptr == ' ') {
-                    ptr++;
-                    continue;
-                }
-                args[nargs++] = ReadUint16(ptr);
-            }
-            uint16_t ret = LaunchFile(fname, l, nargs, args);
             WriteUint16ln(ret);
         } else if (*ptr == 'w') {
             dump = false;
@@ -314,6 +339,17 @@ bool ParseCommand(const char* buf, uint16_t& cur_addr, uint16_t& cur_seg) {
                 __set_far_u8__(addr, cur_seg, d);
                 addr++;
             }
+        } else if (*ptr == 'k') {
+            dump = false;
+            ptr++;
+            uint16_t args[2];
+            // TODO: implement copy on non-zero segments
+            if (cur_seg == 0 && ReadArgs(ptr, args, 2) == 2) {
+                auto* src = reinterpret_cast<uint8_t*>(args[0]);
+                uint16_t size = args[1];
+                auto* dest = reinterpret_cast<uint8_t*>(cur_addr);
+                memcpy(dest, src, size);
+            }
         } else {
             cur_addr = ReadUint16(ptr);
         }