Prepare scheduling

kernel/include/paging.hpp

@@ -20,6 +20,8 @@ struct process_t;
 
 namespace paging {
 
+//TODO Probably some of it could be moved in the source file
+
 typedef uint64_t* page_entry;
 typedef page_entry* pt_t;
 typedef pt_t* pd_t;
@@ -101,6 +103,8 @@ void map_kernel_inside_user(scheduler::process_t& process);
 bool user_map(scheduler::process_t& process, size_t virt, size_t physical);
 bool user_map_pages(scheduler::process_t& process, size_t virt, size_t physical, size_t pages);
 
+size_t get_physical_pml4t();
+
 } //end of namespace paging
 
 #endif

kernel/include/process.hpp

@@ -21,12 +21,20 @@ struct segment_t {
 };
 
 struct process_t {
+    size_t pid;
+
+    bool system;
+
     size_t physical_cr3;
     size_t paging_size;
 
     size_t physical_user_stack;
     size_t physical_kernel_stack;
 
+    size_t rip;
+    size_t user_rsp;
+    size_t kernel_rsp;
+
     std::vector<segment_t> segments;
     std::vector<size_t> physical_paging;
 };

kernel/include/scheduler.hpp

@@ -13,6 +13,10 @@ namespace scheduler {
 void init();
 void start();
 
+void kill_current_process();
+
+void reschedule();
+
 } //end of namespace scheduler
 
 #endif

kernel/include/stl/vector.hpp

@@ -84,20 +84,15 @@ public:
 
     //Modifiers
 
-    void push_back(const value_type& element){
+    void push_back(value_type&& element){
-        if(_capacity == 0){
+        ensure_capacity();
-            _capacity = 1;
-            data = new T[_capacity];
-        } else if(_capacity == _size){
-            _capacity= _capacity * 2;
 
-            auto new_data = new T[_capacity];
+        data[_size++] = std::forward<value_type>(element);
-            std::move_n(new_data, data, _size);
-
-            delete[] data;
-            data = new_data;
     }
 
+    void push_back(const value_type& element){
+        ensure_capacity();
+
         data[_size++] = element;
     }
 
@@ -126,6 +121,22 @@ public:
     constexpr const_iterator end() const {
         return const_iterator(&data[_size]);
     }
+
+private:
+    void ensure_capacity(){
+        if(_capacity == 0){
+            _capacity = 1;
+            data = new T[_capacity];
+        } else if(_capacity == _size){
+            _capacity= _capacity * 2;
+
+            auto new_data = new T[_capacity];
+            std::move_n(new_data, data, _size);
+
+            delete[] data;
+            data = new_data;
+        }
+    }
 };
 
 } //end of namespace std

kernel/src/paging.cpp

@@ -519,3 +519,7 @@ bool paging::user_map_pages(scheduler::process_t& process, size_t virt, size_t p
 
     return true;
 }
+
+size_t paging::get_physical_pml4t(){
+    return physical_pml4t_start;
+}

kernel/src/scheduler.cpp

@@ -0,0 +1,77 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2014.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#include "scheduler.hpp"
+#include "process.hpp"
+#include "paging.hpp"
+#include "assert.hpp"
+
+#include "console.hpp"
+
+namespace {
+
+std::vector<scheduler::process_t> processes;
+size_t current_pid;
+
+size_t next_pid = 1;
+
+void idle_task(){
+    while(true){
+        asm volatile("hlt");
+    }
+}
+
+size_t idle_stack[64];
+size_t idle_kernel_stack[4096]; //TODO Perhaps not good
+
+void create_idle_task(){
+    scheduler::process_t idle_process;
+    idle_process.pid = next_pid++;
+    idle_process.system = true;
+    idle_process.physical_cr3 = paging::get_physical_pml4t();
+    idle_process.paging_size = 0;
+
+    idle_process.physical_user_stack = 0;
+    idle_process.physical_kernel_stack = 0;
+
+    idle_process.rip = reinterpret_cast<size_t>(&idle_task);
+    idle_process.user_rsp = reinterpret_cast<size_t>(&idle_stack[63]);
+    idle_process.kernel_rsp = reinterpret_cast<size_t>(&idle_kernel_stack[4095]);
+
+    processes.push_back(std::move(idle_process));
+}
+
+void switch_to_process(size_t pid){
+    current_pid = pid;
+
+    k_printf("Switched to %u\n", current_pid);
+
+    //TODO
+}
+
+} //end of anonymous namespace
+
+void scheduler::init(){
+    //Create the idle task
+    create_idle_task();
+}
+
+void scheduler::start(){
+    thor_assert(!processes.empty(), "There should at least be the idle task");
+
+    switch_to_process(processes.size() - 1);
+}
+
+void scheduler::kill_current_process(){
+    k_printf("Kill %u\n", current_pid);
+
+    //TODO
+}
+
+void scheduler::reschedule(){
+    //TODO
+}

kernel/src/shell.cpp

@@ -24,6 +24,7 @@
 #include "gdt.hpp"
 #include "vesa.hpp"
 #include "process.hpp"
+#include "scheduler.hpp"
 
 #include "physical_allocator.hpp"
 #include "virtual_allocator.hpp"
@@ -868,6 +869,8 @@ void exec_command(const std::vector<std::string>& params){
         return;
     }
 
+    scheduler::init();
+
     auto content = read_elf_file(params[1], "exec");
 
     if(!content){