Add base code for custom stack length

os/process.h

@@ -1,3 +1,4 @@
+#include <stddef.h>
 #ifndef PROCESS_H
 #include <stdint.h>
 
@@ -7,9 +8,14 @@
 #define STACK_SIZE 32
 #define STACK_START(stack)  (&stack[STACK_SIZE-1])
 
+typedef struct {
+    uint32_t stack_size;
+    uint32_t stack[];
+} ProcessStack;
+
 typedef struct {
     int (*entrypoint)();
-    uint32_t stack[STACK_SIZE];
+    ProcessStack* stack;
 } Process;
 
 typedef struct {
@@ -19,5 +25,7 @@ typedef struct {
 
 void create_process_table(ProcessTable **table);
 
+ProcessStack* create_stack(size_t size);
+
 int create_process(ProcessTable *table, void *entrypoint);
 #endif