Added kill syscall

src/common/common.c

@@ -48,6 +48,10 @@ void fclose(uint32_t fh) {
   asm volatile("mov $16, %%eax; mov %0, %%esi; int $0x7f" : : "m" (fh) : "esi");
 }
 
+void kill(uint32_t pid) {
+  asm volatile("mov $17, %%eax; mov %0, %%esi; int $0x7f" : : "m" (pid) : "esi");
+}
+
 void bindToKeyboard() {
   asm volatile ("mov $12, %%eax; int $0x7f" : : :);
 }

src/common/common.h

@@ -21,6 +21,7 @@ void bindToKeyboard();
 
 int fopen(char* filename);
 void fclose(uint32_t fh);
+void kill(uint32_t pid);
 
 int int_to_decimal(unsigned int number, char* string_buffer);
 int int_to_hex(unsigned int number, char* string_buffer);

src/kernel/idt.cpp

@@ -167,6 +167,8 @@ void syscall(frame_struct* frame) {
   // 15: fopen :: char* path esi -> int filehandler // Returns a filehandler to the file.
   // 16: fclose :: int filehandler esi -> void // Closes a file handler.
 
+  // 17: kill :: int PID esi -> void // Destroys a process.
+
   // File handlers:
   // 0: Stdout
   // 1: Stdin
@@ -288,6 +290,7 @@ void syscall(frame_struct* frame) {
     case 15: {
       ReadWriter* file = new FATFileReadWriter(0, esi);
       rval = Global::kernel->mapFH(file);
+      break;
     }
 
     case 16: {
@@ -296,6 +299,18 @@ void syscall(frame_struct* frame) {
         delete f.get();
         Global::kernel->unmapFH(esi);
       }
+      break;
+    }
+
+    case 17: {
+      asm("cli");
+      xnoe::Maybe<Process*> p = Global::kernel->pid_map->get(esi);
+      if (p.is_ok()) {
+        Process* proc = p.get();
+        Global::kernel->destroyProcess(proc);
+      }
+      asm("sti");
+      break;
     }
 
     default:

src/kernel/kernel.cpp

@@ -39,6 +39,8 @@ Process* Kernel::createProcess(uint32_t fh, ReadWriter* stdout) {
 }
 
 void Kernel::destroyProcess(Process* p) {
+  if (Global::currentProc == p)
+    Global::currentProcValid = false;
   this->processes.remove(p);
   this->pid_map->remove(p->PID);
   delete p;

src/kernel/process.cpp

@@ -95,16 +95,20 @@ Process::Process(uint32_t PID, PageDirectory* inherit, uint32_t inheritBase, uin
 }
 
 Process::~Process() {
+  uint32_t pCR3;
+  asm ("mov %%cr3, %0" : "=a" (pCR3) :);
+  this->PD->select();
   xnoe::linkedlistelem<AllocTracker>* next = allocations.start;
   while (next) {
     xnoe::linkedlistelem<AllocTracker>* active = next;
     next = next->next;
 
-    printf("Deleted %x\n", active->elem.page_base);
+    //printf("Deleted %x\n", active->elem.page_base);
 
     this->deallocate(active->elem.page_base+1);
   }
   this->deallocate(stack);
+  asm ("mov %0, %%cr3" : : "r" (pCR3));
   delete kernelStackPtr;
 }
 

src/world/world.c

@@ -49,6 +49,14 @@ void writeToBuf(char c, procbuffer* buf) {
   }
 }
 
+void clearBuf(procbuffer* buf) {
+  for (int i=0; i<21*38;i++) {
+    buf->buffer[i] = ' ';
+  }
+  buf->x = 0;
+  buf->y = 0;
+}
+
 void writeStrToBuf(char* c, procbuffer* b) {
   char* s = c;
   while(*s)
@@ -203,10 +211,12 @@ int main() {
 
   while (1) {
     char c;
-    if (read(1, b1.stdout, &c))
-      writeToBuf(c, &b1);
-    if (read(1, b2.stdout, &c))
-      writeToBuf(c, &b2);
+    if (b1.process)
+      if (read(1, b1.stdout, &c))
+        writeToBuf(c, &b1);
+    if (b2.process)
+      if (read(1, b2.stdout, &c))
+        writeToBuf(c, &b2);
     if (read(1, 1, &c)) {
       if (c == ':') {
         char buf[32] = {0};
@@ -231,9 +241,32 @@ int main() {
           writeStrToBuf(":load <filename>\n", selectedBuf);
           writeStrToBuf("  Loads and executes the program <filename>\n", selectedBuf);
           writeStrToBuf("--------\n", selectedBuf);
+        } else if (strcmpcnt(4, buf, "kill")) {
+          if (selectedBuf->process) {
+            kill(selectedBuf->process);
+            clearBuf(selectedBuf);
+            selectedBuf->process = 0;
+            selectedBuf->stdin = 0;
+            selectedBuf->stdout = 0;
+            if (selectedBuf == &b1) {
+              selectedBuf = &b2;
+            } else {
+              selectedBuf = &b1;
+            }
+          }
+        } else if (strcmpcnt(4, buf, "load")) {
+          if (!selectedBuf->process) {
+            char* potFn = buf+5;
+            uint32_t fh = fopen(potFn);
+            selectedBuf->process = fork(fh);
+            selectedBuf->stdout = bindStdout(selectedBuf->process);
+            selectedBuf->stdin = bindStdin(selectedBuf->process);
+            fclose(fh);
+          }
         }
       } else {
-        write(1, selectedBuf->stdin, &c);
+        if (selectedBuf->process)
+          write(1, selectedBuf->stdin, &c);
       }
     }