Add base code for custom stack length

os/process.c

@@ -1,15 +1,23 @@
 #include "process.h"
 #include "alloc.h"
+#include <stdint.h>
 
 void create_process_table(ProcessTable **table) {
     *table = malloc(sizeof(ProcessTable));
     (*table)->entries = 0;
 }
 
+ProcessStack* create_stack(size_t size) {
+    ProcessStack* stack = malloc(sizeof(ProcessStack) + size*sizeof(uint32_t));
+    stack->stack_size = size;
+    return stack;
+}
+
 int create_process(ProcessTable *table, void *entrypoint) {
     if (table->entries>=MAX_PROCESS) return 1;
 
     Process *pentry = &table->process_list[table->entries++];
     pentry->entrypoint = entrypoint;
+    pentry->stack = create_stack(STACK_SIZE);
     return 0;
 }