wip: thread and processes handle

src/multitasking/thread.c

@@ -0,0 +1,47 @@
+#include "thread.h"
+#include "alloc.h"
+#include "assert.h"
+#include "interrupts.h"
+#include "memory.h"
+#include "string.h"
+#include "thread.h"
+
+struct tcb *create_thread(struct pcb *process, void (*routine)(void))
+{
+	static uint32_t tid = 1;
+	struct tcb *new_tcb = vmalloc(sizeof(struct tcb));
+	if (!new_tcb)
+		return NULL;
+	new_tcb->tid = tid++;
+
+	new_tcb->esp0 = alloc_pages(STACK_SIZE, NULL);
+	if (!new_tcb->esp0) {
+		vfree(new_tcb);
+		return NULL;
+	}
+	// set esp to "skip" the 4 GPRs and eip later to be used as the context
+	// of the thread
+	new_tcb->esp = new_tcb->esp0 + STACK_SIZE - 5 * 4;
+	memcpy(new_tcb->esp + 4, routine, 4);
+	new_tcb->process = process;
+	new_tcb->next = NULL;
+	new_tcb->state = NEW;
+
+	struct tcb *it = process->thread_list;
+	while (it)
+		it = it->next;
+	it = new_tcb;
+
+	return new_tcb;
+}
+
+void delete_thread(struct tcb *thread)
+{
+	vfree(thread->esp0);
+	struct tcb *it = thread->process->thread_list;
+	assert(it);
+	while (it->next != thread)
+		it = it->next;
+	it->next = it->next->next;
+	vfree(thread);
+}