MAXVA 44 kernel/memlayout.h #define TRAMPOLINE (MAXVA - PGSIZE) MAXVA 88 kernel/vm.c if(va >= MAXVA) MAXVA 114 kernel/vm.c if(va >= MAXVA) MAXVA 366 kernel/vm.c if(va0 >= MAXVA) MAXVA 2151 user/usertests.c volatile uint64 a = MAXVA;