ref: 2b5e9756f86ce90bec3f739037a0ee192e16fafe
dir: /sys/src/9/boot/boot.h/
enum {
Debug = 0,
};
extern char* bootdisk;
extern void fatal(char*);
extern int readfile(char*, char*, int);
extern void run(char*, ...);
extern void setenv(char*, char*, int);
extern int writefile(char*, char*, int);