fix: simple multitasking work !!!!

add a stack at every task, and execute task while multitasking switching

headers/task.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "list.h"
+#include "memory.h"
 
 #include <stdint.h>
 
@@ -9,6 +10,8 @@ extern struct task *current_task;
 enum status { ZOMBIE, THREAD, RUN };
 enum owner { OWNER_KERNEL, OWNER_USER };
 
+#define STACK_SIZE PAGE_SIZE * 4
+
 struct task {
 	uint32_t *esp;
 	uint32_t *esp0;

src/drivers/clock.c

@@ -41,6 +41,7 @@ static void clock_handler(struct registers *regs)
 	if (scheduler_counter % 10 == 0) {
 		cli();
 		scheduler();
+		sti();
 	}
 	scheduler_counter++;
 	sleep_counter--;

src/kernel.c

@@ -43,8 +43,9 @@ static void owo(void)
 
 static void awa(void)
 {
+	kprintf("awa\n");
 	while (true)
-		; // kprintf("awa\n");
+		;
 }
 
 void kernel_main(multiboot_info_t *mbd, uint32_t magic)
@@ -62,5 +63,8 @@ void kernel_main(multiboot_info_t *mbd, uint32_t magic)
 	/*         "Martin 03:50, 22 March 2009 (UTC)\n"); */
 	create_kernel_task();
 	exec_fn(awa);
+	exec_fn(awa);
+	exec_fn(awa);
+	exec_fn(awa);
 	shell_init();
 }

src/multitasking/switch_to_task.s

@@ -14,41 +14,40 @@ switch_to_task:
 	// save the current stack pointer to the old stack
 	mov [eax+0], esp
 
-	// save the old eip pointer
-	mov ebx, [[[esp_backup]]]
-	mov [eax+16], ebx
-
 	// stack pointer + the 4 regs pushed
 	// and + 1 to get the argument (next task)
 	mov esi, [esp+(4+1)*4]
 	mov [current_task], esi
 
-	mov edi, [current_task]
+	mov eax, [current_task]
 
-	mov esp, [edi+0] // esp
+	mov esp, [eax+0] // get esp
-	mov eax, [edi+4] // esp0
-//	mov ebx, [edi+8] // cr3
-//	mov edi, [edi+12] // page_directory
-//	mov [page_directory], edi
-//	mov [TSS+4], eax // tss.esp0
-//	mov ecx, cr3
 
-	// if cr3 hasn't change, do nothing
-//	cmp ecx, ebx
-//	je .END 
-//	mov cr3, ebx
-
-
-.END:
-	mov eax, [edi+16]
-	mov ebx, [esp_backup]
-	mov [ebx], eax
-	
 	pop esi
 	pop edi
 	pop ebp
 	pop ebx
 
+
+	mov ecx, 0
+
+	cmp [eax+16], ecx
+	je .END
+
 	sti
 
+	push [eax+16] // store func_ptr
+
+	mov [eax+16], ecx // clear eip in current_task
+
+	push 0
+	call pic_send_eoi
+	pop edx // remove pic_send_eoi argument
+
+	pop edx // get func_ptr
+	call edx
+
+	// TODO HANDLE TASK RETURN
+
+.END:
 	ret 

src/multitasking/task.c

@@ -19,9 +19,16 @@ static struct task *create_task(uint8_t owner_id)
 	new_task->prev = current_task;
 	current_task->next = new_task;
 	new_task->owner_id = owner_id;
+	new_task->esp0 = alloc_pages(STACK_SIZE, NULL);
+	if (!new_task->esp0) {
+		vfree(new_task);
+		return NULL;
+	}
+	new_task->esp = new_task->esp0 + STACK_SIZE;
 	new_task->pid = pid++;
 	new_task->heap = alloc_pages(4096, (void **)&new_task->cr3);
 	if (!new_task->heap) {
+		free_pages(new_task->esp0, STACK_SIZE);
 		vfree(new_task);
 		return NULL;
 	}
@@ -33,9 +40,11 @@ int create_kernel_task(void)
 	struct task *new_task = vmalloc(sizeof(struct task));
 	if (!new_task)
 		return -1;
+	new_task->status = RUN;
 	new_task->owner_id = 0;
 	new_task->pid = 0;
 	new_task->heap = page_directory;
+	new_task->cr3 = page_directory - KERNEL_START;
 	new_task->prev = new_task;
 	new_task->next = new_task;
 	current_task = new_task;