syscalls: close to being done with fork syscall

include/task.h

@@ -68,6 +68,8 @@ typedef struct Process
 } Process;
 
 extern Process* current;
+extern uint32_t pid_counter;
+extern Process* queue;
 
 Process* task_create(uint32_t func, uint32_t user_esp, uint32_t ring, uint32_t* pagedir);
 

src/tasking/syscalls.c

@@ -62,19 +62,70 @@ int sys_fork(TrapFrame *tf)
 {
     debug_log("FORKFORKFORKFORK\n");
 
-    uint32_t* new_pd = copy_page_dir(current->pagedir) - 0xC0000000;
+    uint32_t* new_pd = copy_page_dir(current->pagedir);
-    debug_log("got this shit done hehe\n");
+    if (!new_pd) {
+        debug_log("Failed to copy page directory\n");
+        return -1;
+    }
+    debug_log("new_pd: %X\n", new_pd);
 
-    set_page_dir((uint32_t)new_pd - 0xC0000000);
+    void *p_physical = alloc_page();
-    while(1){}
+    if (!p_physical) {
+        destroy_page_dir(new_pd);
+        return -1;
+    }
+    Process* child = (Process*)((uint32_t)p_physical + 0xC0000000);
+    map_page(p_physical, (void*)child, PAGE_PRESENT | PAGE_RW);
+    memset(child, 0, sizeof(Process));
 
-    Process* child = task_create(0, 0, 3, new_pd);
+    child->pid = ++pid_counter;
+    child->state = Ready;
+    child->ring = current->ring;
+    child->pagedir = new_pd;
+
+    void *kstack_physical = alloc_page();
+    if (!kstack_physical) {
+        destroy_page_dir(new_pd);
+        free_page(p_physical);
+        debug_log("Failed to allocate kernel stack\n");
+        return -1;
+    }
+    child->kstack = (char*)((uint32_t)kstack_physical + 0xC0000000);
+    map_page(kstack_physical, child->kstack, PAGE_PRESENT | PAGE_RW);
+    debug_log("child->kstack: %X\n", child->kstack);
 
-    memcpy(child, current, sizeof(Process));
     memcpy(child->kstack, current->kstack, KSTACKSIZE);
+    debug_log("Kernel stack copied\n");
 
-    child->tf->eax = 0;
+    uint32_t tf_offset = (uint32_t)current->tf - (uint32_t)current->kstack;
-    tf->eax = child->pid;
+    child->tf = (TrapFrame*)((uint32_t)child->kstack + tf_offset);
+    debug_log("child->tf: %X\n", child->tf);
+
+    if (current->context) {
+        uint32_t context_offset = (uint32_t)current->context - (uint32_t)current->kstack;
+        child->context = (Context*)((uint32_t)child->kstack + context_offset);
+        debug_log("child->context: %X\n", child->context);
+    }
+
+    *child->tf = *tf;
+    child->tf->eax = 0;       // Child returns 0
+    debug_log("Parent returns PID: %X, Child returns 0\n", child->pid);
+
+    for (int i = 0; i < MAX_OPEN_FILES; i++) {
+        child->file_descriptors[i] = current->file_descriptors[i];
+    }
+    debug_log("File descriptors copied\n");
+
+    if (!queue) {
+        queue = child;
+        current = queue;
+    } else {
+        Process* curr = queue;
+        while (curr->next)
+            curr = curr->next;
+        curr->next = child;
+    }
+    debug_log("Child added to queue\n");
 
     return child->pid;
 }
@@ -168,7 +219,6 @@ int sys_close(TrapFrame *tf)
 
 void handle_syscall(TrapFrame *tf)
 {
-    asm("cli");
     /*
     debug_log("EAX: %X ", tf->eax);
     debug_log("EBX: %X ", tf->ebx);
@@ -182,9 +232,10 @@ void handle_syscall(TrapFrame *tf)
         tf->eax = r;
     }
 
-    if(tf->eax == 2)
+    if(tf->eax == 2)//fork
     {
         int r = sys_fork(tf);
+        debug_log("RRRRRRRR = %X\n", r);
         tf->eax = r;
     }
     
@@ -209,5 +260,4 @@ void handle_syscall(TrapFrame *tf)
         int r = sys_close(tf);
         tf->eax = r;
     }
-    asm("sti");
 }