diff --git a/arch/sparc32/init.fs b/arch/sparc32/init.fs
index 4a66241..f2e2cb0 100644
--- a/arch/sparc32/init.fs
+++ b/arch/sparc32/init.fs
@@ -52,12 +52,6 @@
  
 device-end
 
-: sparc32-reset-all
-  h# 71f00000 1 iow!
-  ;
-
-' sparc32-reset-all to reset-all
-
 : rmap@    ( virt -- rmentry )
   drop 0
   ;
diff --git a/arch/sparc32/romvec.c b/arch/sparc32/romvec.c
index 56308ce..b0047cd 100644
--- a/arch/sparc32/romvec.c
+++ b/arch/sparc32/romvec.c
@@ -244,7 +244,7 @@ static int obp_nbputchar(int ch)
 
 static void obp_reboot(char *str)
 {
-    extern volatile int *reset_reg;
+    extern volatile unsigned char *reset_reg;
 
     printk("rebooting (%s)\n", str);
     *reset_reg = 1;
@@ -254,7 +254,7 @@ static void obp_reboot(char *str)
 
 static void obp_abort(void)
 {
-    extern volatile int *power_reg;
+    extern volatile unsigned char *power_reg;
 
     printk("abort, power off\n");
     *power_reg = 1;
@@ -264,7 +264,7 @@ static void obp_abort(void)
 
 static void obp_halt(void)
 {
-    extern volatile int *power_reg;
+    extern volatile unsigned char *power_reg;
 
     printk("halt, power off\n");
     *power_reg = 1;
diff --git a/drivers/iommu.c b/drivers/iommu.c
index 6c48a52..5be307a 100644
--- a/drivers/iommu.c
+++ b/drivers/iommu.c
@@ -195,7 +195,7 @@ map_io(uint64_t pa, int size)
     unsigned int mva;
 
     off = pa & (PAGE_SIZE - 1);
-    npages = (off + (size - 1) + (PAGE_SIZE - 1)) / PAGE_SIZE;
+    npages = (off + size - 1) / PAGE_SIZE + 1;
     pa &= ~(PAGE_SIZE - 1);
 
     va = mem_alloc(&cio, npages * PAGE_SIZE, PAGE_SIZE);
diff --git a/drivers/obio.c b/drivers/obio.c
index 2c684a0..64965aa 100644
--- a/drivers/obio.c
+++ b/drivers/obio.c
@@ -812,7 +812,13 @@ ob_auxio_init(uint64_t base, uint64_t offset)
     fword("finish-device");
 }
 
-volatile int *power_reg, *reset_reg;
+volatile unsigned char *power_reg, *reset_reg;
+
+static void
+sparc32_reset_all(void)
+{
+    *reset_reg = 1;
+}
 
 static void
 ob_power_init(uint64_t base, uint64_t offset, int intr)
@@ -824,6 +830,10 @@ ob_power_init(uint64_t base, uint64_t offset, int intr)
     // Not in device tree
     reset_reg = map_io(base + (uint64_t)SLAVIO_RESET, RESET_REGS);
 
+    bind_func("sparc32-reset-all", sparc32_reset_all);
+    push_str("' sparc32-reset-all to reset-all");
+    fword("eval");
+
     ob_intr(intr);
 
     fword("finish-device");