diff --git a/kernel/arch/i386/arch_do_vmctl.c b/kernel/arch/i386/arch_do_vmctl.c
index 56b081b14..79f1dc9dd 100644
--- a/kernel/arch/i386/arch_do_vmctl.c
+++ b/kernel/arch/i386/arch_do_vmctl.c
@@ -12,7 +12,7 @@
 
 #include "proto.h"
 
-extern u32_t *vm_pagedirs;
+extern u8_t *vm_pagedirs;
 
 /*===========================================================================*
  *				arch_do_vmctl				     *
@@ -64,7 +64,7 @@ struct proc *p;
 	}
 	case VMCTL_I386_PAGEDIRS:
 	{
-		vm_pagedirs = (u32_t *) m_ptr->SVMCTL_VALUE;
+		vm_pagedirs = (u8_t *) m_ptr->SVMCTL_VALUE;
 		return OK;
 	}
 	case VMCTL_I386_FREEPDE:
diff --git a/kernel/arch/i386/hw_intr.h b/kernel/arch/i386/hw_intr.h
index 278a82716..1665b7818 100644
--- a/kernel/arch/i386/hw_intr.h
+++ b/kernel/arch/i386/hw_intr.h
@@ -5,8 +5,8 @@
 
 /* legacy PIC */
 
-_PROTOTYPE(int irq_8259_unmask,(int irq));
-_PROTOTYPE(int irq_8259_mask,(int irq));
+_PROTOTYPE(void irq_8259_unmask,(int irq));
+_PROTOTYPE(void irq_8259_mask,(int irq));
 _PROTOTYPE(void irq_handle,(int irq));
 
 #define hw_intr_mask(irq)	irq_8259_mask(irq)
diff --git a/kernel/arch/i386/i8259.c b/kernel/arch/i386/i8259.c
index 70c781830..afab1e213 100644
--- a/kernel/arch/i386/i8259.c
+++ b/kernel/arch/i386/i8259.c
@@ -23,8 +23,6 @@
 #define ICW4_PC_AEOI_SLAVE   0x0B /* not SFNM, buffered, auto EOI, 8086 */
 #define ICW4_PC_AEOI_MASTER  0x0F /* not SFNM, buffered, auto EOI, 8086 */
 
-#define set_vec(nr, addr)	((void)0)
-
 /*===========================================================================*
  *				intr_init				     *
  *===========================================================================*/
diff --git a/kernel/arch/i386/memory.c b/kernel/arch/i386/memory.c
index 8f640bffa..331ae3b04 100644
--- a/kernel/arch/i386/memory.c
+++ b/kernel/arch/i386/memory.c
@@ -31,7 +31,7 @@ PRIVATE int psok = 0;
 				I386_PAGE_SIZE * pr->p_nr +	\
 				I386_VM_PT_ENT_SIZE * pi))
 
-u8_t *vm_pagedirs = NULL;
+PUBLIC u8_t *vm_pagedirs = NULL;
 
 #define NOPDE (-1)
 #define PDEMASK(n) (1L << (n))
@@ -41,7 +41,7 @@ PRIVATE int nfreepdes = 0, freepdes[WANT_FREEPDES], inusepde = NOPDE;
 
 #define HASPT(procptr) ((procptr)->p_seg.p_cr3 != 0)
 
-FORWARD _PROTOTYPE( u32_t phys_get32, (vir_bytes v)			);
+FORWARD _PROTOTYPE( u32_t phys_get32, (phys_bytes v)			);
 FORWARD _PROTOTYPE( void vm_enable_paging, (void)			);
 FORWARD _PROTOTYPE( void set_cr3, (void)			);
 
@@ -423,9 +423,10 @@ vir_bytes bytes;                /* # of bytes to be copied */
 	u32_t phys = 0;
 
 	if(seg == MEM_GRANT) {
-		phys = umap_grant(rp, vir_addr, bytes);
-	} else {
-		if(!(linear = umap_local(rp, seg, vir_addr, bytes))) {
+		return umap_grant(rp, vir_addr, bytes);
+	}
+	
+	if(!(linear = umap_local(rp, seg, vir_addr, bytes))) {
 			kprintf("SYSTEM:umap_virtual: umap_local failed\n");
 			phys = 0;
 		} else {
@@ -436,7 +437,7 @@ vir_bytes bytes;                /* # of bytes to be copied */
 			if(phys == 0)
 				minix_panic("vm_lookup returned phys", phys);
 		}
-	}
+	
 
 	if(phys == 0) {
 		kprintf("SYSTEM:umap_virtual: lookup failed\n");
@@ -517,22 +518,6 @@ PUBLIC int vm_lookup(struct proc *proc, vir_bytes virtual, vir_bytes *physical,
 	NOREC_RETURN(vmlookup, OK);
 }
 
-/* From virtual address v in process p,
- * lookup physical address and assign it to d.
- * If p is NULL, assume it's already a physical address.
- */
-#define LOOKUP(d, p, v, flagsp) {	\
-	int r; 				\
-	if(!(p)) { (d) = (v); } 	\
-	else {				\
-		if((r=vm_lookup((p), (v), &(d), flagsp)) != OK) { \
-			kprintf("vm_copy: lookup failed of 0x%lx in %d (%s)\n"\
-				"kernel stacktrace: ", (v), (p)->p_endpoint, \
-					(p)->p_name);		\
-			util_stacktrace();			\
-			return r;				\
-		} } }
-
 /*===========================================================================*
  *                              vm_contiguous                                *
  *===========================================================================*/
@@ -770,7 +755,7 @@ int vm_phys_memset(phys_bytes ph, u8_t c, phys_bytes bytes)
 	 */
 	while(bytes > 0) {
 		int pde, t;
-		vir_bytes chunk = bytes;
+		vir_bytes chunk = (vir_bytes) bytes;
 		phys_bytes ptr;
 		inusepde = NOPDE;
 		CREATEPDE(((struct proc *) NULL), ptr, ph, chunk, bytes, pde, t);
@@ -1047,7 +1032,7 @@ PUBLIC arch_phys_map(int index, phys_bytes *addr, phys_bytes *len, int *flags)
 #endif
 }
 
-PUBLIC arch_phys_map_reply(int index, vir_bytes addr)
+PUBLIC int arch_phys_map_reply(int index, vir_bytes addr)
 {
 #ifdef CONFIG_APIC
 	/* if local APIC is enabled */
diff --git a/kernel/main.c b/kernel/main.c
index 9437ebaf0..d154e94af 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -54,7 +54,7 @@ PUBLIC void main()
   }
   for (sp = BEG_PRIV_ADDR, i = 0; sp < END_PRIV_ADDR; ++sp, ++i) {
 	sp->s_proc_nr = NONE;			/* initialize as free */
-	sp->s_id = i;				/* priv structure index */
+	sp->s_id = (proc_nr_t) i;		/* priv structure index */
 	ppriv_addr[i] = sp;			/* priv ptr from number */
   }
 
@@ -70,7 +70,8 @@ PUBLIC void main()
   ktsb = (reg_t) t_stack;
 
   for (i=0; i < NR_BOOT_PROCS; ++i) {
-	int schedulable_proc, proc_nr;
+	int schedulable_proc;
+	proc_nr_t proc_nr;
 	int ipc_to_m, kcalls;
 
 	ip = &image[i];				/* process' attributes */
@@ -112,6 +113,10 @@ PUBLIC void main()
                 ipc_to_m = RSYS_M;                 /* allowed targets */
                 kcalls = RSYS_KC;                  /* allowed kernel calls */
             }
+            /* Priviliges for ordinary process. */
+            else {
+		NOT_REACHABLE;
+            }
 
             /* Fill in target mask. */
             for (j=0; j < NR_SYS_PROCS; j++) {
diff --git a/kernel/proc.c b/kernel/proc.c
index 5096608f8..4ee6592ab 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -506,7 +506,7 @@ long bit_map;			/* notification event set or flags */
 PRIVATE int deadlock(function, cp, src_dst) 
 int function;					/* trap number */
 register struct proc *cp;			/* pointer to caller */
-int src_dst;					/* src or dst process */
+proc_nr_t src_dst;				/* src or dst process */
 {
 /* Check for deadlock. This can happen if 'caller_ptr' and 'src_dst' have
  * a cyclic dependency of blocking send and receive calls. The only cyclic 
diff --git a/kernel/proto.h b/kernel/proto.h
index dbd979852..c06c4a1cb 100644
--- a/kernel/proto.h
+++ b/kernel/proto.h
@@ -56,7 +56,7 @@ _PROTOTYPE( int get_priv, (register struct proc *rc, int proc_type)	);
 _PROTOTYPE( void set_sendto_bit, (struct proc *rc, int id)		);
 _PROTOTYPE( void unset_sendto_bit, (struct proc *rc, int id)		);
 _PROTOTYPE( void send_sig, (int proc_nr, int sig_nr)			);
-_PROTOTYPE( void cause_sig, (int proc_nr, int sig_nr)			);
+_PROTOTYPE( void cause_sig, (proc_nr_t proc_nr, int sig_nr)			);
 _PROTOTYPE( void sig_delay_done, (struct proc *rp)			);
 _PROTOTYPE( void sys_task, (void)					);
 #define numap_local(proc_nr, vir_addr, bytes) \
diff --git a/kernel/system.c b/kernel/system.c
index 3d2692479..93ba522c0 100644
--- a/kernel/system.c
+++ b/kernel/system.c
@@ -337,7 +337,7 @@ PUBLIC void send_sig(int proc_nr, int sig_nr)
  *				cause_sig				     *
  *===========================================================================*/
 PUBLIC void cause_sig(proc_nr, sig_nr)
-int proc_nr;			/* process to be signalled */
+proc_nr_t proc_nr;		/* process to be signalled */
 int sig_nr;			/* signal to be sent */
 {
 /* A system process wants to send a signal to a process.  Examples are:
diff --git a/kernel/system/do_copy.c b/kernel/system/do_copy.c
index e46d33f28..cf42a75ee 100644
--- a/kernel/system/do_copy.c
+++ b/kernel/system/do_copy.c
@@ -83,7 +83,7 @@ register message *m_ptr;	/* pointer to request message */
   /* Check for overflow. This would happen for 64K segments and 16-bit 
    * vir_bytes. Especially copying by the PM on do_fork() is affected. 
    */
-  if (bytes != (vir_bytes) bytes) return(E2BIG);
+  if (bytes != (phys_bytes) (vir_bytes) bytes) return(E2BIG);
 
   /* Now try to make the actual virtual copy. */
   return( virtual_copy_vmcheck(&vir_addr[_SRC_], &vir_addr[_DST_], bytes) );
diff --git a/kernel/system/do_kill.c b/kernel/system/do_kill.c
index dacf43d42..ac27db68c 100644
--- a/kernel/system/do_kill.c
+++ b/kernel/system/do_kill.c
@@ -28,7 +28,7 @@ message *m_ptr;			/* pointer to request message */
   proc_nr_t proc_nr, proc_nr_e;
   int sig_nr = m_ptr->SIG_NUMBER;
 
-  proc_nr_e= m_ptr->SIG_ENDPT;
+  proc_nr_e= (proc_nr_t) m_ptr->SIG_ENDPT;
 
   if (!isokendpt(proc_nr_e, &proc_nr)) return(EINVAL);
   if (sig_nr >= _NSIG) return(EINVAL);
diff --git a/kernel/system/do_safecopy.c b/kernel/system/do_safecopy.c
index c13d963ef..402941e0e 100644
--- a/kernel/system/do_safecopy.c
+++ b/kernel/system/do_safecopy.c
@@ -45,7 +45,7 @@ endpoint_t *e_granter;		/* new granter (magic grants) */
 {
 	static cp_grant_t g;
 	static int proc_nr;
-	static struct proc *granter_proc;
+	static const struct proc *granter_proc;
 	int r, depth = 0;
 
 	do {
diff --git a/kernel/system/do_safemap.c b/kernel/system/do_safemap.c
index b76c52876..403f8638f 100644
--- a/kernel/system/do_safemap.c
+++ b/kernel/system/do_safemap.c
@@ -121,7 +121,7 @@ PUBLIC int map_invoke_vm(int req_type, /* VMPTYPE_... COWMAP, SMAP, SUNMAP */
 		size_t size, int flag)
 {
 	struct proc *caller, *src, *dst;
-	vir_bytes lin_src, lin_dst;
+	phys_bytes lin_src, lin_dst;
 
 	src = endpoint_lookup(end_s);
 	dst = endpoint_lookup(end_d);
@@ -154,7 +154,7 @@ PUBLIC int map_invoke_vm(int req_type, /* VMPTYPE_... COWMAP, SMAP, SUNMAP */
 	caller->p_vmrequest.params.map.vir_d = lin_dst;	/* destination addr */
 	caller->p_vmrequest.params.map.ep_s = end_s;	/* source process */
 	caller->p_vmrequest.params.map.vir_s = lin_src;	/* source address */
-	caller->p_vmrequest.params.map.length = size;
+	caller->p_vmrequest.params.map.length = (vir_bytes) size;
 	caller->p_vmrequest.params.map.writeflag = flag;
 
 	caller->p_vmrequest.type = VMSTYPE_MAP;
@@ -175,10 +175,10 @@ register message *m_ptr;
 {
 	endpoint_t grantor	= m_ptr->SMAP_EP;
 	cp_grant_id_t gid	= m_ptr->SMAP_GID;
-	vir_bytes offset	= m_ptr->SMAP_OFFSET;
-	int seg			= (int)m_ptr->SMAP_SEG;
-	vir_bytes address	= m_ptr->SMAP_ADDRESS;
-	vir_bytes bytes		= m_ptr->SMAP_BYTES;
+	vir_bytes offset	= (vir_bytes) m_ptr->SMAP_OFFSET;
+	int seg			= (int) m_ptr->SMAP_SEG;
+	vir_bytes address	= (vir_bytes) m_ptr->SMAP_ADDRESS;
+	vir_bytes bytes		= (vir_bytes) m_ptr->SMAP_BYTES;
 	int flag		= m_ptr->SMAP_FLAG;
 
 	vir_bytes offset_result;
diff --git a/kernel/utility.c b/kernel/utility.c
index 228f3afc4..07989df5e 100644
--- a/kernel/utility.c
+++ b/kernel/utility.c
@@ -15,10 +15,7 @@
 /*===========================================================================*
  *			panic                                        *
  *===========================================================================*/
-PUBLIC void panic(what, mess,nr)
-char *what;
-char *mess;
-int nr;
+PUBLIC void panic(char *what, char *mess,int nr)
 {
 /* This function is for when a library call wants to panic.
  * The library call calls printf() and tries to exit a process,
@@ -30,9 +27,7 @@ int nr;
 /*===========================================================================*
  *			minix_panic                                        *
  *===========================================================================*/
-PUBLIC void minix_panic(mess,nr)
-char *mess;
-int nr;
+PUBLIC void minix_panic(char *mess,int nr)
 {
 /* The system has run aground of a fatal kernel error. Terminate execution. */
 if (minix_panicing++) {