tasking: fix separate page directory creation for new ring0 tasks

src/mm/paging.c

@@ -141,6 +141,11 @@ uint32_t create_page_dir()
         new_pd[i] = current_pd[i];
     }
 
+    int vga_pde_index = 0; // Virtual address 0x000B8000 is covered by PDE[0]
+    if (current_pd[vga_pde_index] & PAGE_PRESENT) {
+        new_pd[vga_pde_index] = current_pd[vga_pde_index];
+    }
+
     new_pd[1023] = (uint32_t)ppp | 0x03;  // Present + Read/Write
 
     return (uint32_t)new_pd;

src/tasking/switch.asm

@@ -33,6 +33,7 @@ switchProcess:
     mov [current], edx      ; current = next_process_ptr
 
     mov eax, [edx + 40]
+    sub eax, 0xC0000000
     mov cr3, eax
 
     pop edi

src/tasking/task.c

@@ -24,15 +24,18 @@ extern uint32_t task_count;
 
 Process* task_create(uint32_t func, void** args, uint32_t arg_count, uint32_t ring)
 {
-    Process* p = (Process*)alloc_page();
+    void *p_physical = alloc_page();
+    Process* p = (Process*)((uint32_t)p_physical+0xC0000000);
+    map_page(p_physical, (void*)p, PAGE_PRESENT | PAGE_RW);
     memset(p, 0, sizeof(Process));
     p->pid = ++pid_counter;
     p->state = Ready;
     p->ring = ring;
 
     // Выделяем стек ядра
-    p->kstack = (char*)alloc_page();
+    void *kstack_physical = alloc_page();
-    map_page(p->kstack, p->kstack, PAGE_PRESENT | PAGE_RW);
+    p->kstack = (char*)((uint32_t)kstack_physical+0xC0000000);
+    map_page(kstack_physical, p->kstack, PAGE_PRESENT | PAGE_RW);
     printf("kstack: %X!!!!!!!!!!!!\n", p->kstack);
     uint8_t* sp = (uint8_t*)(p->kstack + KSTACKSIZE);
 
@@ -71,7 +74,7 @@ Process* task_create(uint32_t func, void** args, uint32_t arg_count, uint32_t ri
     p->context->eip = (uint32_t)trapret;
     p->kesp = (uint32_t)sp;
 
-    p->page_directory = ring == 0 ? kpage_dir : (uint32_t*)create_page_dir();
+    p->page_directory = (uint32_t*)create_page_dir();
 
     p->next = 0;
 
@@ -144,7 +147,7 @@ void scheduler_init()
     task_create((uint32_t)task1, args1, 2, 0);
     void* args2[] = {(void*)69, (void*)420};
     task_create((uint32_t)task2, args2, 2, 0);
-	jump_usermode2();
+	//jump_usermode2();
 }
 
 #include "../include/string.h"