diff --git a/share/man/man4/ddb.4 b/share/man/man4/ddb.4
index 62de79a6f2db..488c75d81c01 100644
--- a/share/man/man4/ddb.4
+++ b/share/man/man4/ddb.4
@@ -59,7 +59,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 27, 2006
+.Dd August 6, 2007
 .Dt DDB 4
 .Os
 .Sh NAME
@@ -522,6 +522,12 @@ The support of the
 modifier depends on the machine.
 If not supported, incorrect information will be displayed.
 .Pp
+.It Ic show Cm sysregs
+Show system registers (e.g.,
+.Li cr0-4
+on i386.)
+Not present on some platforms.
+.Pp
 .It Ic show Cm geom Op Ar addr
 If the
 .Ar addr
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index df3b5eb2b165..79319754d686 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -1587,6 +1587,25 @@ DB_SHOW_COMMAND(idt, db_show_idt)
 		ip++;
 	}
 }
+
+/* Show privileged registers. */
+DB_SHOW_COMMAND(sysregs, db_show_sysregs)
+{
+	uint64_t idtr, gdtr;
+
+	idtr = ridt();
+	db_printf("idtr\t0x%08x/%04x\n",
+	    (u_int)(idtr >> 16), (u_int)idtr & 0xffff);
+	gdtr = rgdt();
+	db_printf("gdtr\t0x%08x/%04x\n",
+	    (u_int)(gdtr >> 16), (u_int)gdtr & 0xffff);
+	db_printf("ldtr\t0x%04x\n", rldt());
+	db_printf("tr\t0x%04x\n", rtr());
+	db_printf("cr0\t0x%08x\n", rcr0());
+	db_printf("cr2\t0x%08x\n", rcr2());
+	db_printf("cr3\t0x%08x\n", rcr3());
+	db_printf("cr4\t0x%08x\n", rcr4());
+}
 #endif
 
 void
diff --git a/sys/i386/include/cpufunc.h b/sys/i386/include/cpufunc.h
index 9a646f6cce22..f3f671503a3b 100644
--- a/sys/i386/include/cpufunc.h
+++ b/sys/i386/include/cpufunc.h
@@ -326,28 +326,28 @@ read_eflags(void)
 	return (ef);
 }
 
-static __inline u_int64_t
+static __inline uint64_t
 rdmsr(u_int msr)
 {
-	u_int64_t rv;
+	uint64_t rv;
 
 	__asm __volatile("rdmsr" : "=A" (rv) : "c" (msr));
 	return (rv);
 }
 
-static __inline u_int64_t
+static __inline uint64_t
 rdpmc(u_int pmc)
 {
-	u_int64_t rv;
+	uint64_t rv;
 
 	__asm __volatile("rdpmc" : "=A" (rv) : "c" (pmc));
 	return (rv);
 }
 
-static __inline u_int64_t
+static __inline uint64_t
 rdtsc(void)
 {
-	u_int64_t rv;
+	uint64_t rv;
 
 	__asm __volatile("rdtsc" : "=A" (rv));
 	return (rv);
@@ -366,7 +366,7 @@ write_eflags(u_int ef)
 }
 
 static __inline void
-wrmsr(u_int msr, u_int64_t newval)
+wrmsr(u_int msr, uint64_t newval)
 {
 	__asm __volatile("wrmsr" : : "A" (newval), "c" (msr));
 }
@@ -456,6 +456,14 @@ rfs(void)
 	return (sel);
 }
 
+static __inline uint64_t
+rgdt(void)
+{
+	uint64_t gdtr;
+	__asm __volatile("sgdt %0" : "=m" (gdtr));
+	return (gdtr);
+}
+
 static __inline u_int
 rgs(void)
 {
@@ -464,6 +472,22 @@ rgs(void)
 	return (sel);
 }
 
+static __inline uint64_t
+ridt(void)
+{
+	uint64_t idtr;
+	__asm __volatile("sidt %0" : "=m" (idtr));
+	return (idtr);
+}
+
+static __inline u_short
+rldt(void)
+{
+	u_short ldtr;
+	__asm __volatile("sldt %0" : "=g" (ldtr));
+	return (ldtr);
+}
+
 static __inline u_int
 rss(void)
 {
@@ -472,6 +496,14 @@ rss(void)
 	return (sel);
 }
 
+static __inline u_short
+rtr(void)
+{
+	u_short tr;
+	__asm __volatile("str %0" : "=g" (tr));
+	return (tr);
+}
+
 static __inline void
 load_fs(u_int sel)
 {
@@ -677,8 +709,8 @@ u_int	rcr0(void);
 u_int	rcr2(void);
 u_int	rcr3(void);
 u_int	rcr4(void);
-u_int64_t rdmsr(u_int msr);
-u_int64_t rdpmc(u_int pmc);
+uint64_t rdmsr(u_int msr);
+uint64_t rdpmc(u_int pmc);
 u_int	rdr0(void);
 u_int	rdr1(void);
 u_int	rdr2(void);
@@ -687,13 +719,17 @@ u_int	rdr4(void);
 u_int	rdr5(void);
 u_int	rdr6(void);
 u_int	rdr7(void);
-u_int64_t rdtsc(void);
+uint64_t rdtsc(void);
 u_int	read_eflags(void);
 u_int	rfs(void);
+uint64_t rgdt(void);
 u_int	rgs(void);
+uint64_t ridt(void);
+u_short	rldt(void);
+u_short	rtr(void);
 void	wbinvd(void);
 void	write_eflags(u_int ef);
-void	wrmsr(u_int msr, u_int64_t newval);
+void	wrmsr(u_int msr, uint64_t newval);
 
 #endif	/* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */