Add missing files

os/process.h

@@ -0,0 +1,23 @@
+#ifndef PROCESS_H
+#include <stdint.h>
+
+#define PROCESS_H
+#define MAX_PROCESS 16
+
+#define STACK_SIZE 32
+#define STACK_START(stack)  (&stack[STACK_SIZE-1])
+
+typedef struct {
+    int (*entrypoint)();
+    uint32_t stack[STACK_SIZE];
+} Process;
+
+typedef struct {
+    Process process_list[MAX_PROCESS];
+    int entries;
+} ProcessTable;
+
+void create_process_table(ProcessTable **table);
+
+int create_process(ProcessTable *table, void *entrypoint);
+#endif