wip: context switch when switching to another process

src/kernel.c

@@ -55,7 +55,8 @@ void kernel_main(multiboot_info_t *mbd, uint32_t magic)
 	terminal_initialize();
 	create_process(1);
 	create_thread(current_pcb, shell_init);
-	create_thread(current_pcb, uwu);
+	create_process(2);
+	create_thread(current_pcb->next, uwu);
 	toris();
 	while (true)
 		;

src/multitasking/scheduler.c

@@ -37,6 +37,8 @@ void scheduler(uint32_t *esp)
 		kpanic("No existing threads \n");
 	if (current_tcb)
 		current_tcb->esp = esp;
+	if (thread_to_switch->process != current_pcb)
+		switch_process(thread_to_switch->process);
 	current_tcb = thread_to_switch;
 	switch_thread(thread_to_switch->esp);
 }

src/multitasking/switch_process.s

@@ -0,0 +1,16 @@
+.intel_syntax noprefix
+.extern current_pcb
+
+.section .text
+	.global switch_process
+
+switch_process:
+	// change current_pcb global
+	mov eax, [esp + 4]
+	mov [current_pcb], eax
+	
+	// reload cr3 with the new heap
+	mov edx, [eax + 0]
+	mov cr3, edx
+
+	ret