wip: thread and processes handle

src/multitasking/process.c

@@ -0,0 +1,57 @@
+#include "process.h"
+#include "alloc.h"
+#include "interrupts.h"
+#include "memory.h"
+
+#include "string.h"
+
+int8_t create_kernel_process(void)
+{
+	struct pcb *new_pcb = vmalloc(sizeof(struct pcb));
+	if (!new_pcb)
+		return -1;
+	new_pcb->pid = 0;
+	new_pcb->uid = 0;
+	new_pcb->heap = kernel_pd;
+	new_pcb->cr3 = (uint32_t *)((uint32_t)kernel_pd - HEAP_END);
+	new_pcb->next = new_pcb;
+	new_pcb->prev = new_pcb;
+	return 0;
+}
+
+struct pcb *create_process(uint8_t uid)
+{
+	static uint32_t pid = 1;
+	struct pcb *new_pcb = vmalloc(sizeof(struct pcb));
+	if (!new_pcb)
+		return NULL;
+	new_pcb->uid = uid;
+	new_pcb->pid = pid++;
+
+	new_pcb->heap = alloc_pages(4096, &new_pcb->cr3);
+	if (!new_pcb->heap) {
+		vfree(new_pcb);
+		return NULL;
+	}
+	memcpy(new_pcb->heap, current_pcb->heap, 4096);
+	new_pcb->next = current_pcb->next;
+	new_pcb->prev = current_pcb;
+	current_pcb->next = new_pcb;
+	if (current_pcb->prev == current_pcb)
+		current_pcb->prev = new_pcb;
+
+	new_pcb->signals.pending = SIG_IGN;
+
+	return new_pcb;
+}
+
+void remove_pcb(struct pcb *pcb)
+{
+	struct pcb *left = pcb->prev;
+	struct pcb *right = pcb->next;
+	if (pcb->heap)
+		free_pages(pcb->heap, 4096);
+	left->next = right;
+	right->prev = left;
+	vfree(pcb);
+}