diff --git a/kernel/main.c b/kernel/main.c
index a136beb..107a20c 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -30,11 +30,10 @@ main()
   } else {
     while(started == 0) {}
     __sync_synchronize();
-    printf("Hart/Core [%d]: Starting\n", cpuid());
+    printf("hart %d starting\n", cpuid());
     kvminithart();  // turn on paging
     trapinithart(); // install kernel trap vector
     plicinithart(); // ask PLIC for device interrupts
-    printf("Hart/Core [%d]: Online\n", cpuid());
   }
 
   scheduler();
diff --git a/kernel/memlayout.h b/kernel/memlayout.h
index ff6d045..57c3839 100644
--- a/kernel/memlayout.h
+++ b/kernel/memlayout.h
@@ -23,8 +23,6 @@
 #define UART0     0x10000000L
 #define UART0_IRQ 10
 
-#define QEMU_POWER 0x100000
-
 // virtio mmio interface
 #define VIRTIO0     0x10001000
 #define VIRTIO0_IRQ 1
diff --git a/kernel/sysproc.c b/kernel/sysproc.c
index 8c1f1d5..ba0aeb9 100644
--- a/kernel/sysproc.c
+++ b/kernel/sysproc.c
@@ -100,6 +100,5 @@ sys_trace(void)
 void
 sys_halt(void)
 {
-  (*(volatile u32 *)QEMU_POWER) = 0x5555;
-  panic("sys_poweroff");
+  /* TODO: Implement sys_halt */
 }
diff --git a/kernel/vm.c b/kernel/vm.c
index af3ff45..c4541bd 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -21,9 +21,6 @@ kvmmake(void)
   kpgtbl = (pagetable_t)kalloc();
   memset(kpgtbl, 0, PGSIZE);
 
-  // Map qemu
-  kvmmap(kpgtbl, QEMU_POWER, QEMU_POWER, PGSIZE, PTE_R | PTE_W);
-
   // uart registers
   kvmmap(kpgtbl, UART0, UART0, PGSIZE, PTE_R | PTE_W);
 
diff --git a/user/halt.c b/user/halt.c
index 9f26b81..ab73dd3 100644
--- a/user/halt.c
+++ b/user/halt.c
@@ -4,7 +4,6 @@
 int
 main(int argc, char *argv[])
 {
-  printf("System powering down...\n");
   halt();
   return 0;
 }