diff --git a/sys/dev/acpi/acpi.c b/sys/dev/acpi/acpi.c
index c78a39f1c738..994b3206f4d6 100644
--- a/sys/dev/acpi/acpi.c
+++ b/sys/dev/acpi/acpi.c
@@ -831,7 +831,10 @@ acpi_attach(device_t dev)
 		acpi_powerres_debug(sc);
 	}
 
-	EVENTHANDLER_REGISTER(shutdown_final, acpi_soft_off, sc, SHUTDOWN_PRI_LAST);
+	EVENTHANDLER_REGISTER(shutdown_pre_sync, acpi_disable_events,
+			      sc, SHUTDOWN_PRI_LAST);
+	EVENTHANDLER_REGISTER(shutdown_final, acpi_soft_off,
+			      sc, SHUTDOWN_PRI_LAST);
 
 	sc->dev_t = make_dev(&acpi_cdevsw, 0, 0, 5, 0660, "acpi");
 	sc->dev_t->si_drv1 = sc;
@@ -962,3 +965,39 @@ acpi_attach_resource(acpi_softc_t *sc, int type, int *wantidx, u_long start, u_l
 		return(ENXIO);
 	}
 }
+
+/*
+ * System service interface
+ */
+
+#include <sys/proc.h>
+
+int
+acpi_sleep(u_int32_t micro)
+{
+	static u_int8_t	count = 0;
+	int		x, error;
+	u_int32_t	timo;
+
+	x = error = 0;
+
+	if (micro == 0) {
+		return (1);
+	}
+
+	if (curproc == NULL) {
+		return (2);
+	}
+
+	timo = ((hz * micro) / 1000000L) ? ((hz * micro) / 1000000L) : 1;
+	error = tsleep((caddr_t)acpi_sleep + count, PWAIT, "acpislp", timo);
+	if (error != 0 && error != EWOULDBLOCK) {
+		return (2);
+	}
+	x = splhigh();
+	count++;
+	splx(x);
+
+	return (0);
+}
+
diff --git a/sys/dev/acpi/acpi_event.c b/sys/dev/acpi/acpi_event.c
index a66ec237af4b..5f965df58a5b 100644
--- a/sys/dev/acpi/acpi_event.c
+++ b/sys/dev/acpi/acpi_event.c
@@ -297,6 +297,19 @@ acpi_enable_events(acpi_softc_t *sc)
     acpi_io_pm_timer(sc, ACPI_REGISTER_INPUT,  &status);
 }
 
+void
+acpi_disable_events(acpi_softc_t *sc)
+{
+    u_int32_t	zero;
+
+    if (sc->enabled) {
+	zero = 0;
+	acpi_io_pm1_enable(sc, ACPI_REGISTER_OUTPUT, &zero);
+	acpi_io_gpe0_enable(sc, ACPI_REGISTER_OUTPUT, &zero);
+	acpi_io_gpe1_enable(sc, ACPI_REGISTER_OUTPUT, &zero);
+    }
+}
+
 void
 acpi_clear_ignore_events(void *arg)
 {
diff --git a/sys/dev/acpi/acpireg.h b/sys/dev/acpi/acpireg.h
index 635c2b7e503c..1d64e92314ab 100644
--- a/sys/dev/acpi/acpireg.h
+++ b/sys/dev/acpi/acpireg.h
@@ -328,6 +328,9 @@ ACPI_STATUS	 OsdReadPciCfgDword(UINT32, UINT32 , UINT32 , UINT32 *);
 ACPI_STATUS	 OsdWritePciCfgByte(UINT32, UINT32 , UINT32 , UINT8);
 ACPI_STATUS	 OsdWritePciCfgWord(UINT32, UINT32 , UINT32 , UINT16);
 ACPI_STATUS	 OsdWritePciCfgDword(UINT32, UINT32 , UINT32 , UINT32);
+
+ACPI_STATUS	 OsdSleep(UINT32, UINT32);
+ACPI_STATUS	 OsdSleepUsec(UINT32);
 #endif	/* ACPI_NO_OSDFUNC_INLINE */
 
 #else	/* !_KERNEL */
diff --git a/sys/dev/acpi/acpivar.h b/sys/dev/acpi/acpivar.h
index d06794d47de1..011a6b100097 100644
--- a/sys/dev/acpi/acpivar.h
+++ b/sys/dev/acpi/acpivar.h
@@ -202,6 +202,7 @@ extern void	acpi_intr(void *data);
 extern void	acpi_queue_event(acpi_softc_t *sc, int type, int arg);
 extern int	acpi_send_pm_event(acpi_softc_t *sc, u_int8_t state);
 extern void	acpi_enable_events(acpi_softc_t *sc);
+extern void	acpi_disable_events(acpi_softc_t *sc);
 extern void	acpi_clear_ignore_events(void *arg);
 extern void 	acpi_event_thread(void *arg);
 
@@ -244,3 +245,9 @@ extern void		acpi_mapmem(void);
 extern int acpi_debug;
 #define ACPI_DEVPRINTF(args...)		printf("acpi0: " args)
 #define ACPI_DEBUGPRINT(args...)	do { if (acpi_debug) ACPI_DEVPRINTF(args);} while(0)
+
+/*
+ * System service interface
+ */
+extern int		acpi_sleep(u_int32_t micro);
+
diff --git a/sys/dev/acpi/aml/aml_common.h b/sys/dev/acpi/aml/aml_common.h
index 4988385d5134..827c324d1e04 100644
--- a/sys/dev/acpi/aml/aml_common.h
+++ b/sys/dev/acpi/aml/aml_common.h
@@ -47,11 +47,15 @@
 	printf(fmt, args);						\
 } while(0)
 #define AML_DEBUGGER(x, y)	/* no debugger in kernel */
+#define AML_STALL(micro)	DELAY(micro)
+#define AML_SLEEP(sec, milli)	OsdSleep(sec, milli)
 #else /* !_KERNEL */
 #define AML_SYSASSERT(x)	assert(x)
 #define AML_SYSABORT()  	abort()
 #define AML_SYSERRX(eval, fmt, args...)	errx(eval, fmt, args)
 #define AML_DEBUGGER(x, y)	aml_dbgr(x, y)
+#define AML_STALL(micro)	/* not required in userland */
+#define AML_SLEEP(sec, milli)	/* not required in userland */
 #endif /* _KERNEL */
 
 union	aml_object;
diff --git a/sys/dev/acpi/aml/aml_parse.c b/sys/dev/acpi/aml/aml_parse.c
index f98977d3bd62..ce40e647fd51 100644
--- a/sys/dev/acpi/aml/aml_parse.c
+++ b/sys/dev/acpi/aml/aml_parse.c
@@ -55,6 +55,14 @@
 #include "debug.h"
 #else /* _KERNEL */
 #include <sys/systm.h>
+#include <sys/bus.h>
+#include <machine/bus.h>
+#include <machine/clock.h>
+#include <dev/acpi/acpireg.h>
+#include <dev/acpi/acpivar.h>
+#ifndef ACPI_NO_OSDFUNC_INLINE
+#include <machine/acpica_osd.h>
+#endif
 #endif /* !_KERNEL */
 
 static int		 findsetleftbit(int num);
@@ -1484,14 +1492,18 @@ aml_parse_termobj(struct aml_environ *env, int indent)
 			aml_parse_termobj(env, indent);
 			AML_DEBUGPRINT(")");
 			break;
-		case 0x21:	/* StallOp *//* XXX Not yet */
+		case 0x21:	/* StallOp */
 			AML_DEBUGPRINT("Stall(");
-			aml_parse_termobj(env, indent);
+			num1 = aml_objtonum(env, aml_eval_name(env,
+			    aml_parse_termobj(env, indent)));
 			AML_DEBUGPRINT(")");
+			AML_STALL(num1);
 			break;
-		case 0x22:	/* SleepOp *//* XXX Not yet */
+		case 0x22:	/* SleepOp */
 			AML_DEBUGPRINT("Sleep(");
-			aml_parse_termobj(env, indent);
+			num1 = aml_objtonum(env, aml_eval_name(env,
+			    aml_parse_termobj(env, indent)));
+			AML_SLEEP(0, num1);
 			AML_DEBUGPRINT(")");
 			break;
 		case 0x23:	/* AcquireOp *//* XXX Not yet */
diff --git a/sys/i386/include/acpica_osd.h b/sys/i386/include/acpica_osd.h
index 9255e74cac6a..63a6466b05aa 100644
--- a/sys/i386/include/acpica_osd.h
+++ b/sys/i386/include/acpica_osd.h
@@ -38,8 +38,16 @@
 #include <vm/vm.h>
 #include <vm/pmap.h>
 
+#include <dev/acpi/acpi.h>
+
 #include "pcib_if.h"
 
+#ifdef ACPI_NO_OSDFUNC_INLINE
+#define _ACPICA_INLINE_
+#else
+#define _ACPICA_INLINE_ static __inline
+#endif
+
 /*
  * ACPICA compatibility
  */
@@ -98,28 +106,19 @@ OsdInX(ACPI_IO_ADDRESS InPort, int bytes)
 	return (retval);
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-UINT8
+_ACPICA_INLINE_ UINT8
 OsdIn8(ACPI_IO_ADDRESS InPort)
 {
 	return (OsdInX(InPort, 1) & 0xff);
 }
  
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-UINT16
+_ACPICA_INLINE_ UINT16
 OsdIn16(ACPI_IO_ADDRESS InPort)
 {
 	return (OsdInX(InPort, 2) & 0xffff);
 }
  
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-UINT32
+_ACPICA_INLINE_ UINT32
 OsdIn32(ACPI_IO_ADDRESS InPort)
 {
 	return (OsdInX(InPort, 4));
@@ -148,37 +147,25 @@ OsdOutX(ACPI_IO_ADDRESS OutPort, UINT32 Value, int bytes)
 	}
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-void
+_ACPICA_INLINE_ void
 OsdOut8(ACPI_IO_ADDRESS OutPort, UINT8 Value)
 {
 	OsdOutX(OutPort, Value, 1);
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-void    
+_ACPICA_INLINE_ void
 OsdOut16(ACPI_IO_ADDRESS OutPort, UINT16 Value)
 {
 	OsdOutX(OutPort, Value, 2);
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-void
+_ACPICA_INLINE_ void
 OsdOut32(ACPI_IO_ADDRESS OutPort, UINT32 Value)
 {
 	OsdOutX(OutPort, Value, 4);
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-ACPI_STATUS
+_ACPICA_INLINE_ ACPI_STATUS
 OsdMapMemory(void *PhysicalAddress, UINT32 Length, void **LogicalAddress)
 {
 	vm_offset_t	PhysicalEnd;
@@ -203,10 +190,7 @@ OsdMapMemory(void *PhysicalAddress, UINT32 Length, void **LogicalAddress)
 	return (AE_OK);
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-void    
+_ACPICA_INLINE_ void
 OsdUnMapMemory(void *LogicalAddress, UINT32 Length)
 {
 
@@ -234,10 +218,7 @@ OsdReadPciCfg(UINT32 Bus, UINT32 DeviceFunction, UINT32 Register, UINT32 *Value,
 	return (AE_OK);
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-ACPI_STATUS
+_ACPICA_INLINE_ ACPI_STATUS
 OsdReadPciCfgByte(UINT32 Bus, UINT32 DeviceFunction, UINT32 Register, UINT8 *Value)
 {
 	ACPI_STATUS	status;
@@ -248,10 +229,7 @@ OsdReadPciCfgByte(UINT32 Bus, UINT32 DeviceFunction, UINT32 Register, UINT8 *Val
 	return (status);
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-ACPI_STATUS
+_ACPICA_INLINE_ ACPI_STATUS
 OsdReadPciCfgWord(UINT32 Bus, UINT32 DeviceFunction, UINT32 Register, UINT16 *Value)
 {
 	ACPI_STATUS	status;
@@ -262,10 +240,7 @@ OsdReadPciCfgWord(UINT32 Bus, UINT32 DeviceFunction, UINT32 Register, UINT16 *Va
 	return (status);
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-ACPI_STATUS
+_ACPICA_INLINE_ ACPI_STATUS
 OsdReadPciCfgDword(UINT32 Bus, UINT32 DeviceFunction, UINT32 Register, UINT32 *Value)
 {
 	ACPI_STATUS	status;
@@ -291,29 +266,53 @@ OsdWritePciCfg(UINT32 Bus, UINT32 DeviceFunction, UINT32 Register, UINT32 Value,
 	return (AE_OK);
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-ACPI_STATUS
+_ACPICA_INLINE_ ACPI_STATUS
 OsdWritePciCfgByte(UINT32 Bus, UINT32 DeviceFunction, UINT32 Register, UINT8 Value)
 {
 	return (OsdWritePciCfg(Bus, DeviceFunction, Register, (UINT32) Value, 1));
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-ACPI_STATUS
+_ACPICA_INLINE_ ACPI_STATUS
 OsdWritePciCfgWord(UINT32 Bus, UINT32 DeviceFunction, UINT32 Register, UINT16 Value)
 {
 	return (OsdWritePciCfg(Bus, DeviceFunction, Register, (UINT32) Value, 2));
 }
 
-#ifndef ACPI_NO_OSDFUNC_INLINE
-static __inline
-#endif
-ACPI_STATUS
+_ACPICA_INLINE_ ACPI_STATUS
 OsdWritePciCfgDword(UINT32 Bus, UINT32 DeviceFunction, UINT32 Register, UINT32 Value)
 {
 	return (OsdWritePciCfg(Bus, DeviceFunction, Register, Value, 4));
 }
+
+_ACPICA_INLINE_ ACPI_STATUS
+OsdSleepUsec(UINT32 Microseconds)
+{
+	int		error;
+	ACPI_STATUS	status;
+
+	error = acpi_sleep(Microseconds);
+	switch (error) {
+	case 0:
+		/* The running thread slept for the time specified */
+		status = AE_OK;
+		break;
+	case 1:
+		/* TBD!!!! */
+		status = AE_BAD_PARAMETER;
+		break;
+	case 2:
+	default:
+		/* The running thread did not slept because of a host OS error */
+		status = AE_ERROR;
+		break;
+	}
+
+	return (status);
+}
+
+_ACPICA_INLINE_ ACPI_STATUS
+OsdSleep(UINT32 Seconds, UINT32 Milliseconds)
+{
+	return OsdSleepUsec(Seconds * 1000000L + Milliseconds * 1000);
+}
+
diff --git a/usr.sbin/acpi/amldb/aml/aml_common.h b/usr.sbin/acpi/amldb/aml/aml_common.h
index 4988385d5134..827c324d1e04 100644
--- a/usr.sbin/acpi/amldb/aml/aml_common.h
+++ b/usr.sbin/acpi/amldb/aml/aml_common.h
@@ -47,11 +47,15 @@
 	printf(fmt, args);						\
 } while(0)
 #define AML_DEBUGGER(x, y)	/* no debugger in kernel */
+#define AML_STALL(micro)	DELAY(micro)
+#define AML_SLEEP(sec, milli)	OsdSleep(sec, milli)
 #else /* !_KERNEL */
 #define AML_SYSASSERT(x)	assert(x)
 #define AML_SYSABORT()  	abort()
 #define AML_SYSERRX(eval, fmt, args...)	errx(eval, fmt, args)
 #define AML_DEBUGGER(x, y)	aml_dbgr(x, y)
+#define AML_STALL(micro)	/* not required in userland */
+#define AML_SLEEP(sec, milli)	/* not required in userland */
 #endif /* _KERNEL */
 
 union	aml_object;
diff --git a/usr.sbin/acpi/amldb/aml/aml_parse.c b/usr.sbin/acpi/amldb/aml/aml_parse.c
index f98977d3bd62..ce40e647fd51 100644
--- a/usr.sbin/acpi/amldb/aml/aml_parse.c
+++ b/usr.sbin/acpi/amldb/aml/aml_parse.c
@@ -55,6 +55,14 @@
 #include "debug.h"
 #else /* _KERNEL */
 #include <sys/systm.h>
+#include <sys/bus.h>
+#include <machine/bus.h>
+#include <machine/clock.h>
+#include <dev/acpi/acpireg.h>
+#include <dev/acpi/acpivar.h>
+#ifndef ACPI_NO_OSDFUNC_INLINE
+#include <machine/acpica_osd.h>
+#endif
 #endif /* !_KERNEL */
 
 static int		 findsetleftbit(int num);
@@ -1484,14 +1492,18 @@ aml_parse_termobj(struct aml_environ *env, int indent)
 			aml_parse_termobj(env, indent);
 			AML_DEBUGPRINT(")");
 			break;
-		case 0x21:	/* StallOp *//* XXX Not yet */
+		case 0x21:	/* StallOp */
 			AML_DEBUGPRINT("Stall(");
-			aml_parse_termobj(env, indent);
+			num1 = aml_objtonum(env, aml_eval_name(env,
+			    aml_parse_termobj(env, indent)));
 			AML_DEBUGPRINT(")");
+			AML_STALL(num1);
 			break;
-		case 0x22:	/* SleepOp *//* XXX Not yet */
+		case 0x22:	/* SleepOp */
 			AML_DEBUGPRINT("Sleep(");
-			aml_parse_termobj(env, indent);
+			num1 = aml_objtonum(env, aml_eval_name(env,
+			    aml_parse_termobj(env, indent)));
+			AML_SLEEP(0, num1);
 			AML_DEBUGPRINT(")");
 			break;
 		case 0x23:	/* AcquireOp *//* XXX Not yet */