diff --git a/kernel/Makefile b/kernel/Makefile
index 1b760c86e..b411e3774 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -6,7 +6,7 @@ PROG=	kernel
 # first-stage, arch-dependent startup code
 SRCS=	mpx.S
 SRCS+=	start.c table.c main.c proc.c \
-	system.c clock.c utility.c debug.c interrupt.c \
+	system.c clock.c utility.c interrupt.c \
 	cpulocals.c
 
 .ifdef CONFIG_SMP
@@ -63,6 +63,14 @@ SRCS+= do_mcontext.c
 CPPFLAGS+= -DUSE_MCONTEXT
 .endif
 
+.if ${USE_DEBUGREG} != "no"
+SRCS+= 	breakpoints.c debugreg.S
+.endif
+
+# Extra debugging routines
+.if ${USE_DEBUG} != "no"
+SRCS+= 	debug.c
+.endif
 
 # These come last, so the profiling buffer is at the end of the data segment
 SRCS+= profile.c do_sprofile.c
diff --git a/kernel/arch/i386/Makefile.inc b/kernel/arch/i386/Makefile.inc
index 4d9f7db13..08fb9fced 100644
--- a/kernel/arch/i386/Makefile.inc
+++ b/kernel/arch/i386/Makefile.inc
@@ -4,9 +4,7 @@
 
 .PATH:	${.CURDIR}/arch/${ARCH}
 SRCS+=	arch_do_vmctl.c \
-	breakpoints.c \
 	arch_clock.c \
-	debugreg.S \
 	do_int86.c \
 	do_iopenable.c \
 	do_readbios.c \
diff --git a/kernel/arch/i386/arch_system.c b/kernel/arch/i386/arch_system.c
index bb48c2afd..a94c3a4a0 100644
--- a/kernel/arch/i386/arch_system.c
+++ b/kernel/arch/i386/arch_system.c
@@ -395,6 +395,7 @@ PUBLIC void arch_init(void)
 #endif
 }
 
+#if DEBUG_SERIAL
 PUBLIC void ser_putc(char c)
 {
         int i;
@@ -414,6 +415,7 @@ PUBLIC void ser_putc(char c)
 #endif
 }
 
+
 /*===========================================================================*
  *				do_ser_debug				     * 
  *===========================================================================*/
@@ -597,6 +599,8 @@ PRIVATE void ser_dump_proc_cpu(void)
 }
 #endif
 
+#endif /* DEBUG_SERIAL */
+
 #if SPROFILE
 
 PUBLIC int arch_init_profile_clock(const u32_t freq)
diff --git a/kernel/clock.c b/kernel/clock.c
index cb41aed29..074dba884 100644
--- a/kernel/clock.c
+++ b/kernel/clock.c
@@ -140,8 +140,11 @@ PUBLIC int timer_int_handler(void)
 				TMR_NEVER : clock_timers->tmr_exp_time;
 		}
 
+#if DEBUG_SERIAL
 		if (do_serial_debug)
 			do_ser_debug();
+#endif
+
 	}
 
 	return(1);					/* reenable interrupts */
diff --git a/kernel/debug.h b/kernel/debug.h
index ce808f31a..58921db7c 100644
--- a/kernel/debug.h
+++ b/kernel/debug.h
@@ -13,6 +13,9 @@
 #include "config.h"
 #endif
 
+/* Debug info via serial (see ser_debug()) */
+#define DEBUG_SERIAL			1
+
 /* Enable prints such as
  *  . send/receive failed due to deadlock or dead source or dead destination
  *  . trap not allowed
@@ -47,6 +50,11 @@
 /* DEBUG_IPCSTATS collects information on who sends messages to whom. */
 #define DEBUG_IPCSTATS			0
 
+#if USE_SMALL
+#undef DEBUG_SERIAL
+#undef DEBUG_ENABLE_IPC_WARNINGS
+#endif
+
 #if DEBUG_DUMPIPC || DEBUG_IPCSTATS	/* either of these needs the hook */
 #define DEBUG_IPC_HOOK			1
 #endif
diff --git a/kernel/start.c b/kernel/start.c
index 55f8a28bf..ba25c665e 100644
--- a/kernel/start.c
+++ b/kernel/start.c
@@ -84,6 +84,7 @@ PUBLIC void cstart(
   if(!value || system_hz < 2 || system_hz > 50000)	/* sanity check */
 	system_hz = DEFAULT_HZ;
 
+#if DEBUG_SERIAL
   /* Intitialize serial debugging */
   value = env_get(SERVARNAME);
   if(value && atoi(value) == 0) {
@@ -92,6 +93,7 @@ PUBLIC void cstart(
   	value = env_get(SERBAUDVARNAME);
   	if (value) serial_debug_baud = atoi(value);
   }
+#endif
 
 #ifdef USE_APIC
   value = env_get("no_apic");
diff --git a/kernel/utility.c b/kernel/utility.c
index 7d6521846..15a043c58 100644
--- a/kernel/utility.c
+++ b/kernel/utility.c
@@ -50,11 +50,13 @@ int c;					/* character to append */
  * to the output driver if an END_OF_KMESS is encountered. 
  */
   if (c != END_OF_KMESS) {
+#if DEBUG_SERIAL
       if (do_serial_debug) {
 	if(c == '\n')
       		ser_putc('\r');
       	ser_putc(c);
       }
+#endif
       kmess.km_buf[kmess.km_next] = c;	/* put normal char in buffer */
       if (kmess.km_size < sizeof(kmess.km_buf))
           kmess.km_size += 1;		
diff --git a/share/mk/bsd.own.mk b/share/mk/bsd.own.mk
index 3c97108e9..7cb676d0b 100644
--- a/share/mk/bsd.own.mk
+++ b/share/mk/bsd.own.mk
@@ -757,7 +757,7 @@ _MKVARS.yes= \
 	MKYP
 #MINIX-specific vars
 _MKVARS.yes+= \
-	MKWATCHDOG MKACPI MKAPIC MKMCONTEXT
+	MKWATCHDOG MKACPI MKAPIC MKMCONTEXT MKDEBUGREG MKDEBUG
 .for var in ${_MKVARS.yes}
 ${var}?=	yes
 .endfor
@@ -822,6 +822,8 @@ MKACPI:=	no
 MKAPIC:=	no
 MKMCONTEXT:=	no
 MKCOVERAGE:=	no
+MKDEBUGREG:=	no
+MKDEBUG:=	no
 .endif
 
 #
@@ -883,7 +885,7 @@ ${var}?= no
 # variable is set to "no".
 #
 .for var in USE_HESIOD USE_INET6 USE_KERBEROS USE_LDAP USE_PAM USE_YP \
-USE_WATCHDOG USE_ACPI USE_APIC USE_MCONTEXT
+USE_WATCHDOG USE_ACPI USE_APIC USE_MCONTEXT USE_DEBUGREG USE_DEBUG
 .if (${${var:S/USE_/MK/}} == "no")
 ${var}:= no
 .else
diff --git a/share/mk/sys.mk b/share/mk/sys.mk
index 01cea435c..28a396fc8 100644
--- a/share/mk/sys.mk
+++ b/share/mk/sys.mk
@@ -247,5 +247,5 @@ NBSD_LIBC=	yes
 
 .if ${COMPILER_TYPE} == "gnu" && defined(MKSMALL) && ${MKSMALL} == "yes"
 DBG=	-Os
-CFLAGS+= -DNDEBUG=1
+CFLAGS+= -DNDEBUG=1 -DUSE_SMALL=1
 .endif