wip: thread and processes handle

src/multitasking/switch_to_thread.s

@@ -0,0 +1,31 @@
+.intel_syntax noprefix
+
+.section .text
+	.global switch_thread
+
+switch_thread:
+	push ebx
+	push ebp
+	push edi
+	push esi
+
+	mov eax, [current_tcb]
+
+	// save the current stack pointer to the old stack
+	mov [eax+0], esp
+
+	// stack pointer + the 4 regs pushed
+	// and + 1 to get the argument (next thread)
+	mov esi, [esp+(4+1)*4]
+	mov [current_tcb], esi
+
+	mov eax, [current_tcb]
+
+	mov esp, [eax+0] // get esp
+
+	pop esi
+	pop edi
+	pop ebp
+	pop ebx
+
+	iret