syscalls: implement read syscall

src/tasking/syscalls.c

@@ -46,6 +46,22 @@ const char* flags_to_mode_str(int flags) {
     return mode;
 }
 
+int sys_read(TrapFrame *tf)
+{
+    if(tf->ebx < 3)
+    {
+        //TODO: implement stdin handling here
+    }
+    else
+    {
+        if(current->file_descriptors[tf->ebx] == NULL)
+        {
+            return -EBADF;
+        }
+        return fat_fread(current->file_descriptors[tf->ebx], (void*)tf->ecx, tf->edx);
+    }
+}
+
 int sys_write(TrapFrame *tf)
 {
     if(tf->ebx < 3)
@@ -53,7 +69,9 @@ int sys_write(TrapFrame *tf)
         //stdin, stdout or stderr
         if(tf->ebx == STDOUT_FILENO)
         {
+            debug_log("\n=================SYS_WRITE output to stdout=====================\n");
             print((char*)tf->ecx, tf->edx);
+            debug_log("\n=================END OF THAT SHIT=====================\n");
             tf->ecx++;
         }
     }
@@ -102,9 +120,12 @@ int sys_open(TrapFrame *tf)
 int sys_close(TrapFrame *tf)
 {
     int fd = tf->ebx;
+    debug_log("SYS_CLOSE: fd = 0x%X", fd);
     if(current->file_descriptors[fd] != NULL)
     {
+        debug_log("SYS_CLOSE: current->file_descriptors[fd] != NULL");
         int result = fat_fclose(current->file_descriptors[fd]);
+        debug_log("SYS_CLOSE: fat_fclose result: 0x%X", result);
         free(current->file_descriptors[fd]);
         current->file_descriptors[fd] = NULL;
         return result;
@@ -120,6 +141,12 @@ void handle_syscall(TrapFrame *tf)
     debug_log("ECX: %s ", tf->ecx);
     debug_log("EDX: %X\n", tf->edx);
     
+    if(tf->eax == 3)//read
+    {
+        int r = sys_read(tf);
+        tf->eax = r;
+    }
+
     if(tf->eax == 4)//write
     {
         int r = sys_write(tf);