Fetching buffer arguments from user space.

os/src/task/task.rs

@@ -1,12 +1,72 @@
+use crate::mm::{MemorySet, MapPermission, PhysPageNum, KERNEL_SPACE, VirtAddr};
+use crate::trap::{TrapContext, trap_handler};
+use crate::config::{TRAP_CONTEXT, kernel_stack_position};
+use super::TaskContext;
+
 pub struct TaskControlBlock {
     pub task_cx_ptr: usize,
     pub task_status: TaskStatus,
+    pub memory_set: MemorySet,
+    pub trap_cx_ppn: PhysPageNum,
+    pub base_size: usize,
 }
 
 impl TaskControlBlock {
     pub fn get_task_cx_ptr2(&self) -> *const usize {
         &self.task_cx_ptr as *const usize
     }
+    pub fn get_trap_cx(&self) -> &'static mut TrapContext {
+        self.trap_cx_ppn.get_mut()
+    }
+    pub fn get_user_token(&self) -> usize {
+        self.memory_set.token()
+    }
+    pub fn new(elf_data: &[u8], app_id: usize) -> Self {
+        //println!("into TCB::new");
+        // memory_set with elf program headers/trampoline/trap context/user stack
+        let (memory_set, user_sp, entry_point) = MemorySet::from_elf(elf_data);
+        //println!("user_sp={:#x},entry_point={:#}", user_sp, entry_point);
+        let trap_cx_ppn = memory_set
+            .translate(VirtAddr::from(TRAP_CONTEXT).into())
+            .unwrap()
+            .ppn();
+        //println!("trap_cx_ppn={:?}", trap_cx_ppn);
+        let task_status = TaskStatus::Ready;
+        // map a kernel-stack in kernel space
+        //println!("mapping kernel-stack!");
+        let (kernel_stack_bottom, kernel_stack_top) = kernel_stack_position(app_id);
+        //println!("kernel_stack={:#x},{:#x}", kernel_stack_bottom, kernel_stack_top);
+        KERNEL_SPACE
+            .lock()
+            .insert_framed_area(
+                kernel_stack_bottom.into(),
+                kernel_stack_top.into(),
+                MapPermission::R | MapPermission::W,
+            );
+        let task_cx_ptr = (kernel_stack_top - core::mem::size_of::<TaskContext>()) as *mut TaskContext;
+        //println!("task_cx size={}", core::mem::size_of::<TaskContext>());
+        //println!("init task_cx, ptr={:p}", task_cx_ptr);
+        unsafe { *task_cx_ptr = TaskContext::goto_trap_return(); }
+        //println!("after init task_cx");
+        let task_control_block = Self {
+            task_cx_ptr: task_cx_ptr as usize,
+            task_status,
+            memory_set,
+            trap_cx_ppn,
+            base_size: user_sp,
+        };
+        // prepare TrapContext in user space
+        //println!("preparing trap_cx");
+        let trap_cx = task_control_block.get_trap_cx();
+        *trap_cx = TrapContext::app_init_context(
+            entry_point,
+            user_sp,
+            KERNEL_SPACE.lock().token(),
+            kernel_stack_top,
+            trap_handler as usize,
+        );
+        task_control_block
+    }
 }
 
 #[derive(Copy, Clone, PartialEq)]