diff -Nru a/Makefile b/Makefile
--- a/Makefile	Sat May 26 15:03:18 2001
+++ b/Makefile	Sat May 26 15:03:18 2001
@@ -1,7 +1,7 @@
 VERSION = 2
 PATCHLEVEL = 2
 SUBLEVEL = 19
-EXTRAVERSION = 
+EXTRAVERSION = -rtl
 
 ARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ -e s/arm.*/arm/ -e s/sa110/arm/)
 
@@ -436,7 +436,7 @@
 
 dep-files: scripts/mkdep archdep include/linux/version.h new-genksyms
 	scripts/mkdep init/*.c > .depend
-	scripts/mkdep `find $(FINDHPATH) -follow -name \*.h ! -name modversions.h -print` > .hdepend
+	scripts/mkdep `find $(FINDHPATH) -name SCCS -prune -or -follow -name \*.h ! -name modversions.h -print` > .hdepend
 #	set -e; for i in $(SUBDIRS); do $(MAKE) -C $$i fastdep ;done
 # let this be made through the fastdep rule in Rules.make
 	$(MAKE) $(patsubst %,_sfdep_%,$(SUBDIRS)) _FASTDEP_ALL_SUB_DIRS="$(SUBDIRS)"
diff -Nru a/arch/i386/config.in b/arch/i386/config.in
--- a/arch/i386/config.in	Sat May 26 15:03:18 2001
+++ b/arch/i386/config.in	Sat May 26 15:03:18 2001
@@ -2,7 +2,12 @@
 # For a description of the syntax of this configuration file,
 # see Documentation/kbuild/config-language.txt.
 #
-mainmenu_name "Linux Kernel Configuration"
+mainmenu_name "RTLinux Kernel Configuration"
+define_bool CONFIG_RTLINUX  y
+
+if [ "$CONFIG_RTLINUX" = "y" ]; then
+  define_bool CONFIG_RTL y
+fi
 
 mainmenu_option next_comment
 comment 'Code maturity level options'
diff -Nru a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile
--- a/arch/i386/kernel/Makefile	Sat May 26 15:03:18 2001
+++ b/arch/i386/kernel/Makefile	Sat May 26 15:03:18 2001
@@ -13,7 +13,7 @@
 all: kernel.o head.o init_task.o
 
 O_TARGET := kernel.o
-O_OBJS   := process.o signal.o entry.o traps.o irq.o vm86.o \
+O_OBJS   := process.o signal.o entry.o traps.o irq.o vm86.o rtlinux.o \
             ptrace.o ioport.o ldt.o setup.o time.o sys_i386.o \
 	    bluesmoke.o
 OX_OBJS  := i386_ksyms.o dmi_scan.o
diff -Nru a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
--- a/arch/i386/kernel/entry.S	Sat May 26 15:03:18 2001
+++ b/arch/i386/kernel/entry.S	Sat May 26 15:03:18 2001
@@ -166,7 +166,22 @@
  * but we want the default path for a system call return to
  * go as quickly as possible which is why some of this is
  * less clear than it otherwise should be.
+ *
+ * (c) Victor Yodaiken 1999
+ * RTLINUX_IRET emulates the turn on interrupts effect of
+ * iret since, under RTLinux we may have pended interrupts
+ * that will not be automatically enabled on an iret.
  */
+#ifdef CONFIG_RTLINUX
+#define RTLINUX_IRET 	\
+	movl  rtl_emulate_iret,%eax; \
+	testl %eax, %eax; \
+        je  1f;	\
+        call  *%eax;	\
+        1:
+#else
+#define RTLINUX_IRET 
+#endif
 
 ENTRY(system_call)
 	pushl %eax			# save orig_eax
@@ -191,11 +206,13 @@
 	cmpl $0,sigpending(%ebx)
 	jne signal_return
 restore_all:
+        RTLINUX_IRET
 	RESTORE_ALL
 
 	ALIGN
 signal_return:
 	sti				# we can get here from an interrupt handler
+	RTLINUX_IRET
 	testl $(VM_MASK),EFLAGS(%esp)
 	movl %esp,%eax
 	jne v86_signal_return
@@ -250,6 +267,12 @@
 	call SYMBOL_NAME(schedule)    # test
 	jmp ret_from_sys_call
 
+#define RTL_PUSH_VECTOR(vector,routine) \
+1:	cmpl $routine, %edi; \
+	jne 1f; \
+	pushl $vector; \
+	jmp 7f;
+
 ENTRY(divide_error)
 	pushl $0		# no error code
 	pushl $ SYMBOL_NAME(do_divide_error)
@@ -277,6 +300,35 @@
 	movl $(__KERNEL_DS),%edx
 	movl %dx,%ds
 	movl %dx,%es
+#ifdef CONFIG_RTLINUX
+	movl  rtl_exception_intercept,%eax
+	testl %eax, %eax
+        je  8f
+	RTL_PUSH_VECTOR(0,do_divide_error)
+	RTL_PUSH_VECTOR(1,do_debug)
+	RTL_PUSH_VECTOR(3,do_int3)
+	RTL_PUSH_VECTOR(4,do_overflow)
+	RTL_PUSH_VECTOR(5,do_bounds)
+	RTL_PUSH_VECTOR(6,do_invalid_op)
+	RTL_PUSH_VECTOR(8,do_double_fault)
+	RTL_PUSH_VECTOR(9,do_coprocessor_segment_overrun)
+	RTL_PUSH_VECTOR(10,do_invalid_TSS)
+	RTL_PUSH_VECTOR(11,do_segment_not_present)
+	RTL_PUSH_VECTOR(12,do_stack_segment)
+	RTL_PUSH_VECTOR(13,do_general_protection)
+	RTL_PUSH_VECTOR(14,do_page_fault)
+	RTL_PUSH_VECTOR(15,do_spurious_interrupt_bug)
+	RTL_PUSH_VECTOR(16,do_coprocessor_error)
+	RTL_PUSH_VECTOR(17,do_alignment_check)
+1:	push $-1
+7: 	call  *%eax
+	popl %ebx
+	testl %eax, %eax
+	je 8f
+	addl $8,%esp
+	RESTORE_ALL
+8:
+#endif
 	GET_CURRENT(%ebx)
 	call *%edi
 	addl $8,%esp
@@ -290,6 +342,21 @@
 ENTRY(device_not_available)
 	pushl $-1		# mark this as an int
 	SAVE_ALL
+#ifdef CONFIG_RTLINUX
+	movl  rtl_exception_intercept,%eax
+	testl %eax, %eax
+        je  8f
+	movl %esp,%edx
+	pushl $0		# no error code
+	pushl %edx
+	pushl $7		# vector
+	call  *%eax
+	addl $12,%esp
+	testl %eax, %eax
+	je 8f
+	RESTORE_ALL
+8:
+#endif
 	GET_CURRENT(%ebx)
 	pushl $ret_from_exception
 	movl %cr0,%eax
diff -Nru a/arch/i386/kernel/i386_ksyms.c b/arch/i386/kernel/i386_ksyms.c
--- a/arch/i386/kernel/i386_ksyms.c	Sat May 26 15:03:18 2001
+++ b/arch/i386/kernel/i386_ksyms.c	Sat May 26 15:03:18 2001
@@ -121,3 +121,35 @@
 EXPORT_SYMBOL(screen_info);
 #endif
 
+#ifdef CONFIG_RTLINUX
+#include <linux/vt_kern.h>
+EXPORT_SYMBOL(kd_mksound);
+extern void *__start_rtlinux_funcs,*__stop_rtlinux_funcs;
+EXPORT_SYMBOL(__start_rtlinux_funcs);
+EXPORT_SYMBOL(__stop_rtlinux_funcs);
+EXPORT_SYMBOL(irq_control);
+extern unsigned long (*do_gettimeoffset)(void);
+extern unsigned int use_tsc;
+EXPORT_SYMBOL(do_gettimeoffset);
+EXPORT_SYMBOL(use_tsc);
+EXPORT_SYMBOL(tick);
+extern volatile unsigned long lost_ticks;
+extern rwlock_t xtime_lock;
+EXPORT_SYMBOL(lost_ticks);
+EXPORT_SYMBOL(xtime_lock);
+extern unsigned char *rtl_cached21;
+EXPORT_SYMBOL(rtl_cached21);
+#ifdef CONFIG_SMP
+extern unsigned long irq_affinity [NR_IRQS];
+EXPORT_SYMBOL(irq_affinity);
+#include <asm/smp.h>
+EXPORT_SYMBOL(smp_found_config);
+#endif
+#endif
+
+#ifdef CONFIG_RTLINUX
+extern struct console *console_drivers;
+EXPORT_SYMBOL(console_drivers);
+extern spinlock_t console_lock;
+EXPORT_SYMBOL(console_lock);
+#endif
diff -Nru a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
--- a/arch/i386/kernel/io_apic.c	Sat May 26 15:03:18 2001
+++ b/arch/i386/kernel/io_apic.c	Sat May 26 15:03:18 2001
@@ -196,12 +196,14 @@
 	FINAL;								\
 }
 
+extern unsigned long irq_affinity [NR_IRQS];
+
 /*
  * We disable IO-APIC IRQs by setting their 'destination CPU mask' to
  * zero. Trick by Ramesh Nalluri.
  */
 DO_ACTION( disable, 1, &= 0x00ffffff, io_apic_sync(entry->apic))/* destination = 0x00 */
-DO_ACTION( enable,  1, |= 0xff000000, )				/* destination = 0xff */
+DO_ACTION( enable,  1, |= (irq_affinity[irq] << 24), )				/* destination = 0xff */
 DO_ACTION( mask,    0, |= 0x00010000, io_apic_sync(entry->apic))/* mask = 1 */
 DO_ACTION( unmask,  0, &= 0xfffeffff, )				/* mask = 0 */
 
@@ -1035,7 +1037,7 @@
  * an edge even if it isn't on the 8259A...
  */
 
-static void startup_edge_ioapic_irq(unsigned int irq)
+static unsigned int startup_edge_ioapic_irq(unsigned int irq)
 {
 	if (irq < 16) {
 		disable_8259A_irq(irq);
@@ -1043,6 +1045,7 @@
 			irq_desc[irq].status |= IRQ_PENDING;
 	}
 	enable_edge_ioapic_irq(irq);
+	return 0;
 }
 
 #define shutdown_edge_ioapic_irq	disable_edge_ioapic_irq
@@ -1052,11 +1055,60 @@
  * and shutting down and starting up the interrupt
  * is the same as enabling and disabling them.
  */
-#define startup_level_ioapic_irq	unmask_IO_APIC_irq
+#define startup_level_ioapic_irq	(unsigned int (*)(unsigned int)) unmask_IO_APIC_irq
 #define shutdown_level_ioapic_irq	mask_IO_APIC_irq
 #define enable_level_ioapic_irq		unmask_IO_APIC_irq
 #define disable_level_ioapic_irq	mask_IO_APIC_irq
 
+static void end_edge_ioapic_irq (unsigned int i)
+{
+	unmask_IO_APIC_irq(i);
+}
+
+static void mask_and_ack_edge_ioapic(unsigned int irq){
+	ack_APIC_irq();
+}
+static void mask_and_ack_level_ioapic(unsigned int irq)
+{
+	mask_IO_APIC_irq(irq);
+	ack_APIC_irq();
+}
+
+#define __DO_ACTION(R, ACTION, FINAL)					\
+									\
+{									\
+	int pin;							\
+	struct irq_pin_list *entry = irq_2_pin + irq;			\
+									\
+	for (;;) {							\
+		unsigned int reg;					\
+		pin = entry->pin;					\
+		if (pin == -1)						\
+			break;						\
+		reg = io_apic_read(entry->apic, 0x10 + R + pin*2);	\
+		reg ACTION;						\
+		io_apic_modify(entry->apic, reg);			\
+		if (!entry->next)					\
+			break;						\
+		entry = irq_2_pin + entry->next;			\
+	}								\
+	FINAL;								\
+}
+
+static void set_ioapic_affinity (unsigned int irq, unsigned long mask)
+{
+	unsigned long flags;
+	/*
+	 * Only the first 8 bits are valid.
+	 */
+	irq_affinity[irq] = mask;
+	mask = mask << 24;
+
+/* 	spin_lock_irqsave(&ioapic_lock, flags); */
+	__DO_ACTION(1, = mask, )
+/* 	spin_unlock_irqrestore(&ioapic_lock, flags); */
+}
+
 static void do_edge_ioapic_IRQ(unsigned int irq, struct pt_regs * regs)
 {
 	irq_desc_t *desc = irq_desc + irq;
@@ -1069,7 +1121,7 @@
 	 * Edge triggered IRQs can be acknowledged immediately
 	 * and do not need to be masked.
 	 */
-	ack_APIC_irq();
+	desc->handler->ack(irq);
 	status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
 	status |= IRQ_PENDING;
 
@@ -1106,6 +1158,8 @@
 		spin_unlock(&irq_controller_lock);
 	}
 	desc->status &= ~IRQ_INPROGRESS;
+	if (!(desc->status & IRQ_DISABLED))
+		desc->handler->end(irq);
 	spin_unlock(&irq_controller_lock);
 }
 
@@ -1124,7 +1178,7 @@
 	 * disable has to happen before the ACK, to avoid IRQ storms.
 	 * So this all has to be within the spinlock.
 	 */
-	mask_IO_APIC_irq(irq);
+	desc->handler->ack(irq);
 	status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
 
 	/*
@@ -1138,7 +1192,7 @@
 	}
 	desc->status = status;
 
-	ack_APIC_irq();
+/* 	ack_APIC_irq(); */
 	spin_unlock(&irq_controller_lock);
 
 	/* Exit early if we had no action or it was disabled */
@@ -1150,7 +1204,7 @@
 	spin_lock(&irq_controller_lock);
 	desc->status &= ~IRQ_INPROGRESS;
 	if (!(desc->status & IRQ_DISABLED))
-		unmask_IO_APIC_irq(irq);
+		desc->handler->end(irq);
 	spin_unlock(&irq_controller_lock);
 }
 
@@ -1167,18 +1221,24 @@
 	"IO-APIC-edge",
 	startup_edge_ioapic_irq,
 	shutdown_edge_ioapic_irq,
-	do_edge_ioapic_IRQ,
 	enable_edge_ioapic_irq,
-	disable_edge_ioapic_irq
+	disable_edge_ioapic_irq,
+	mask_and_ack_edge_ioapic,
+	end_edge_ioapic_irq,
+	set_ioapic_affinity,
+	do_edge_ioapic_IRQ,
 };
 
 static struct hw_interrupt_type ioapic_level_irq_type = {
 	"IO-APIC-level",
 	startup_level_ioapic_irq,
 	shutdown_level_ioapic_irq,
-	do_level_ioapic_IRQ,
 	enable_level_ioapic_irq,
-	disable_level_ioapic_irq
+	disable_level_ioapic_irq,
+	mask_and_ack_level_ioapic,
+	end_edge_ioapic_irq,
+	set_ioapic_affinity,
+	do_level_ioapic_IRQ
 };
 
 static inline void init_IO_APIC_traps(void)
diff -Nru a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c
--- a/arch/i386/kernel/irq.c	Sat May 26 15:03:18 2001
+++ b/arch/i386/kernel/irq.c	Sat May 26 15:03:18 2001
@@ -32,6 +32,7 @@
 #include <linux/init.h>
 
 #include <asm/system.h>
+#include <asm/hw_irq.h>
 #include <asm/io.h>
 #include <asm/irq.h>
 #include <asm/bitops.h>
@@ -73,45 +74,60 @@
 /*
  * Dummy controller type for unused interrupts
  */
+
+/* For RTLinux, moved illegal vector warnings into handler->ack -- MB */
 static void do_none(unsigned int irq, struct pt_regs * regs)
 {
-	/*
-	 * we are careful. While for ISA irqs it's common to happen
-	 * outside of any driver (think autodetection), this is not
-	 * at all nice for PCI interrupts. So we are stricter and
-	 * print a warning when such spurious interrupts happen.
-	 * Spurious interrupts can confuse other drivers if the PCI
-	 * IRQ line is shared.
-	 *
-	 * Such spurious interrupts are either driver bugs, or
-	 * sometimes hw (chipset) bugs.
-	 */
-	printk("unexpected IRQ vector %d on CPU#%d!\n",irq, smp_processor_id());
+	struct irqaction * action;
+	irq_desc_t *desc = irq_desc + irq;
+	desc->handler->ack(irq);
+	action = desc->action;
+	if (!action)
+		return;
+	handle_IRQ_event(irq, regs, action);
+}
 
-#ifdef __SMP__
+static void enable_none(unsigned int irq) { }
+static void disable_none(unsigned int irq) { }
+static void ack_none(unsigned int irq)
+{
+/*
+ * 'what should we do if we get a hw irq event on an illegal vector'.
+ * each architecture has to answer this themselves, it doesnt deserve
+ * a generic callback i think.
+ */
+#if CONFIG_X86
+	printk("unexpected IRQ trap at vector %02x\n", irq);
+#ifdef CONFIG_SMP
 	/*
-	 * [currently unexpected vectors happen only on SMP and APIC.
-	 *  if we want to have non-APIC and non-8259A controllers
-	 *  in the future with unexpected vectors, this ack should
-	 *  probably be made controller-specific.]
+	 * Currently unexpected vectors happen only on SMP and APIC.
+	 * We _must_ ack these because every local APIC has only N
+	 * irq slots per priority level, and a 'hanging, unacked' IRQ
+	 * holds up an irq slot - in excessive cases (when multiple
+	 * unexpected vectors occur) that might lock up the APIC
+	 * completely.
 	 */
 	ack_APIC_irq();
 #endif
+#endif
 }
-static void enable_none(unsigned int irq) { }
-static void disable_none(unsigned int irq) { }
+
 
 /* startup is the same as "enable", shutdown is same as "disable" */
-#define startup_none	enable_none
+#define startup_none (unsigned int (*)(unsigned int)) enable_none
 #define shutdown_none	disable_none
+#define end_none	enable_none
 
 struct hw_interrupt_type no_irq_type = {
 	"none",
 	startup_none,
 	shutdown_none,
-	do_none,
 	enable_none,
-	disable_none
+	disable_none,
+	ack_none,
+	end_none,
+	0,
+	do_none,
 };
 
 /*
@@ -120,20 +136,30 @@
  */
 
 static void do_8259A_IRQ(unsigned int irq, struct pt_regs * regs);
+static void mask_and_ack_8259A(unsigned int irq);
 static void enable_8259A_irq(unsigned int irq);
 void disable_8259A_irq(unsigned int irq);
 
 /* startup is the same as "enable", shutdown is same as "disable" */
-#define startup_8259A_irq	enable_8259A_irq
+#define startup_8259A_irq	(unsigned int (*)(unsigned int)) enable_8259A_irq
 #define shutdown_8259A_irq	disable_8259A_irq
 
+static void end_8259A_irq (unsigned int irq)
+{
+	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
+		enable_8259A_irq(irq);
+}
+
 static struct hw_interrupt_type i8259A_irq_type = {
 	"XT-PIC",
 	startup_8259A_irq,
 	shutdown_8259A_irq,
-	do_8259A_IRQ,
 	enable_8259A_irq,
-	disable_8259A_irq
+	disable_8259A_irq,
+	mask_and_ack_8259A,
+	end_8259A_irq,
+	0,
+	do_8259A_IRQ
 };
 
 /*
@@ -154,6 +180,7 @@
 #define __byte(x,y) 	(((unsigned char *)&(y))[x])
 #define cached_21	(__byte(0,cached_irq_mask))
 #define cached_A1	(__byte(1,cached_irq_mask))
+unsigned char *rtl_cached21 = &cached_21;
 
 /*
  * Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
@@ -215,7 +242,7 @@
  * first, _then_ send the EOI, and the order of EOI
  * to the two 8259s is important!
  */
-static inline void mask_and_ack_8259A(unsigned int irq)
+static void mask_and_ack_8259A(unsigned int irq)
 {
 	cached_irq_mask |= 1 << irq;
 	if (irq & 8) {
@@ -238,7 +265,7 @@
 	spin_lock(&irq_controller_lock);
 	{
 		unsigned int status;
-		mask_and_ack_8259A(irq);
+		desc->handler->ack(irq);
 		status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
 		action = NULL;
 		if (!(status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
@@ -260,7 +287,7 @@
 		unsigned int status = desc->status & ~IRQ_INPROGRESS;
 		desc->status = status;
 		if (!(status & IRQ_DISABLED))
-			enable_8259A_irq(irq);
+			desc->handler->enable(irq);
 	}
 	spin_unlock(&irq_controller_lock);
 }
@@ -319,11 +346,11 @@
  * is no hardware IRQ pin equivalent for them, they are triggered
  * through the ICC by us (IPIs)
  */
-BUILD_SMP_INTERRUPT(reschedule_interrupt)
-BUILD_SMP_INTERRUPT(invalidate_interrupt)
-BUILD_SMP_INTERRUPT(stop_cpu_interrupt)
-BUILD_SMP_INTERRUPT(call_function_interrupt)
-BUILD_SMP_INTERRUPT(spurious_interrupt)
+BUILD_SMP_INTERRUPT(reschedule_interrupt, RESCHEDULE_VECTOR)
+BUILD_SMP_INTERRUPT(invalidate_interrupt, INVALIDATE_TLB_VECTOR)
+BUILD_SMP_INTERRUPT(stop_cpu_interrupt, STOP_CPU_VECTOR)
+BUILD_SMP_INTERRUPT(call_function_interrupt, CALL_FUNCTION_VECTOR)
+BUILD_SMP_INTERRUPT(spurious_interrupt, SPURIOUS_APIC_VECTOR)
 
 /*
  * every pentium local APIC has two 'local interrupts', with a
@@ -332,7 +359,7 @@
  * overflow. Linux uses the local APIC timer interrupt to get
  * a much simpler SMP time architecture:
  */
-BUILD_SMP_TIMER_INTERRUPT(apic_timer_interrupt)
+BUILD_SMP_TIMER_INTERRUPT(apic_timer_interrupt, LOCAL_TIMER_VECTOR)
 
 #endif
 
@@ -643,7 +670,7 @@
  */
 void __global_cli(void)
 {
-	unsigned int flags;
+	unsigned long flags;
 
 	__save_flags(flags);
 	if (flags & (1 << EFLAGS_IF_SHIFT)) {
@@ -960,6 +987,8 @@
 out:
 	spin_unlock_irqrestore(&irq_controller_lock,flags);
 }
+
+unsigned long irq_affinity [NR_IRQS] = { [0 ... NR_IRQS-1] = ~0UL };
 
 /*
  * IRQ autodetection code..
diff -Nru a/arch/i386/kernel/irq.h b/arch/i386/kernel/irq.h
--- a/arch/i386/kernel/irq.h	Sat May 26 15:03:18 2001
+++ b/arch/i386/kernel/irq.h	Sat May 26 15:03:18 2001
@@ -2,11 +2,12 @@
 #define __irq_h
 
 #include <asm/irq.h>
+#include <asm/rtlinux.h>
+#include <asm/hw_irq.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
 
 /*
- * Interrupt controller descriptor. This is all we need
- * to describe about the low-level hardware.
- */
 struct hw_interrupt_type {
 	const char * typename;
 	void (*startup)(unsigned int irq);
@@ -15,70 +16,10 @@
 	void (*enable)(unsigned int irq);
 	void (*disable)(unsigned int irq);
 };
+*/
 
 extern struct hw_interrupt_type no_irq_type;
 
-/*
- * IRQ line status.
- */
-#define IRQ_INPROGRESS	1	/* IRQ handler active - do not enter! */
-#define IRQ_DISABLED	2	/* IRQ disabled - do not enter! */
-#define IRQ_PENDING	4	/* IRQ pending - replay on enable */
-#define IRQ_REPLAY	8	/* IRQ has been replayed but not acked yet */
-#define IRQ_AUTODETECT	16	/* IRQ is being autodetected */
-#define IRQ_WAITING	32	/* IRQ not yet seen - for autodetection */
-
-/*
- * This is the "IRQ descriptor", which contains various information
- * about the irq, including what kind of hardware handling it has,
- * whether it is disabled etc etc.
- *
- * Pad this out to 32 bytes for cache and indexing reasons.
- */
-typedef struct {
-	unsigned int status;			/* IRQ status - IRQ_INPROGRESS, IRQ_DISABLED */
-	struct hw_interrupt_type *handler;	/* handle/enable/disable functions */
-	struct irqaction *action;		/* IRQ action list */
-	unsigned int depth;			/* Disable depth for nested irq disables */
-	unsigned int unused[4];
-} irq_desc_t;
-
-/*
- * IDT vectors usable for external interrupt sources start
- * at 0x20:
- */
-#define FIRST_EXTERNAL_VECTOR	0x20
-
-#define SYSCALL_VECTOR		0x80
-
-/*
- * Vectors 0x20-0x2f are used for ISA interrupts.
- */
-
-/*
- * Special IRQ vectors used by the SMP architecture:
- *
- * (some of the following vectors are 'rare', they might be merged
- *  into a single vector to save vector space. TLB, reschedule and
- *  local APIC vectors are performance-critical.)
- */
-#define RESCHEDULE_VECTOR	0x30
-#define INVALIDATE_TLB_VECTOR	0x31
-#define STOP_CPU_VECTOR		0x40
-#define LOCAL_TIMER_VECTOR	0x41
-#define CALL_FUNCTION_VECTOR	0x50
-
-/*
- * First APIC vector available to drivers: (vectors 0x51-0xfe)
- */
-#define IRQ0_TRAP_VECTOR	0x51
-
-/*
- * This IRQ should never happen, but we print a message nevertheless.
- */
-#define SPURIOUS_APIC_VECTOR	0xff
-
-extern irq_desc_t irq_desc[NR_IRQS];
 extern int irq_vector[NR_IRQS];
 #define IO_APIC_VECTOR(irq)	irq_vector[irq]
 
@@ -190,25 +131,30 @@
  *	SMP has a few special interrupts for IPI messages
  */
 
-#define BUILD_SMP_INTERRUPT(x) \
+#define BUILD_SMP_INTERRUPT(x,v) XBUILD_SMP_INTERRUPT(x,v)
+#define XBUILD_SMP_INTERRUPT(x,v)\
 asmlinkage void x(void); \
 __asm__( \
 "\n"__ALIGN_STR"\n" \
 SYMBOL_NAME_STR(x) ":\n\t" \
-	"pushl $-1\n\t" \
+	"pushl $"#v"\n\t" \
 	SAVE_ALL \
-	"call "SYMBOL_NAME_STR(smp_##x)"\n\t" \
+	"pushl $ret_from_intr\n\t" \
+	RTLINUX_LABEL(smp_##x)\
+	"jmp "SYMBOL_NAME_STR(smp_##x)"\n\t" \
 	"jmp ret_from_intr\n");
 
-#define BUILD_SMP_TIMER_INTERRUPT(x) \
+#define BUILD_SMP_TIMER_INTERRUPT(x,v) XBUILD_SMP_TIMER_INTERRUPT(x,v)
+#define XBUILD_SMP_TIMER_INTERRUPT(x,v) \
 asmlinkage void x(struct pt_regs * regs); \
 __asm__( \
 "\n"__ALIGN_STR"\n" \
 SYMBOL_NAME_STR(x) ":\n\t" \
-	"pushl $-1\n\t" \
+	"pushl $"#v"\n\t" \
 	SAVE_ALL \
 	"movl %esp,%eax\n\t" \
 	"pushl %eax\n\t" \
+	RTLINUX_LABEL(smp_##x)\
 	"call "SYMBOL_NAME_STR(smp_##x)"\n\t" \
 	"addl $4,%esp\n\t" \
 	"jmp ret_from_intr\n");
@@ -220,8 +166,9 @@
 	"\n" __ALIGN_STR"\n" \
 	"common_interrupt:\n\t" \
 	SAVE_ALL \
-	"call "SYMBOL_NAME_STR(do_IRQ)"\n\t" \
-	"jmp ret_from_intr\n");
+ 	"pushl $ret_from_intr\n\t" \
+	RTLINUX_LABEL(do_IRQ)"\n\t" \
+ 	"jmp "SYMBOL_NAME_STR(do_IRQ));
 
 /*
  * subtle. orig_eax is used by the signal code to distinct between
diff -Nru a/arch/i386/kernel/rtlinux.c b/arch/i386/kernel/rtlinux.c
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/arch/i386/kernel/rtlinux.c	Sat May 26 15:03:18 2001
@@ -0,0 +1,77 @@
+#include <linux/config.h>
+#include <linux/ptrace.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/timex.h>
+#include <linux/malloc.h>
+#include <linux/random.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <linux/kernel_stat.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/bitops.h>
+#include <asm/pgtable.h>
+#include <asm/delay.h>
+#include <asm/desc.h>
+
+static void rtl_hard_save_flags_f(unsigned long  *z){
+	unsigned long y;
+	rtl_hard_save_flags_kernel(y);
+	*z=y;
+}
+static void rtl_hard_restore_flags_f(unsigned long  x) { rtl_hard_restore_flags_kernel(x); }
+static void rtl_hard_cli_f(void) { rtl_hard_cli_kernel(); }
+static void rtl_hard_sti_f(void) { rtl_hard_sti_kernel(); }
+static void rtl_hard_local_irq_save_f(unsigned long  *x)
+{ unsigned long y;rtl_hard_local_irq_save_kernel(y);*x=y; }
+static void rtl_hard_local_irq_restore_f(unsigned long  x){
+	rtl_hard_local_irq_restore_kernel(x);
+}
+struct irq_control_s irq_control = {
+ 	rtl_hard_save_flags_f,
+ 	rtl_hard_restore_flags_f,
+ 	rtl_hard_cli_f,
+ 	rtl_hard_sti_f,
+ 	rtl_hard_local_irq_save_f,
+ 	rtl_hard_local_irq_restore_f
+ };
+void *rtl_emulate_iret = 0;
+void *rtl_exception_intercept = 0;
+
+extern void *__start_rtlinux_patch,*__stop_rtlinux_patch;
+extern asmlinkage void do_IRQ(struct pt_regs );
+extern void ret_from_intr(void);
+RTLINUX_EXPORT(__start_rtlinux_patch);
+RTLINUX_EXPORT(__stop_rtlinux_patch);
+RTLINUX_EXPORT(rtl_emulate_iret);
+RTLINUX_EXPORT(irq_desc);
+RTLINUX_EXPORT(do_IRQ);
+RTLINUX_EXPORT(ret_from_intr);
+RTLINUX_EXPORT(rtl_exception_intercept);
+
+#ifdef CONFIG_X86_LOCAL_APIC
+extern asmlinkage void smp_spurious_interrupt(void);
+extern asmlinkage void smp_error_interrupt(void);
+extern void smp_apic_timer_interrupt(struct pt_regs *);
+
+RTLINUX_EXPORT(smp_spurious_interrupt);
+RTLINUX_EXPORT(smp_stop_cpu_interrupt);
+RTLINUX_EXPORT(smp_apic_timer_interrupt);
+#endif
+
+#ifdef CONFIG_SMP
+extern void rtl_reschedule(int cpu);
+extern asmlinkage void smp_reschedule_interrupt(void);
+extern asmlinkage void smp_invalidate_interrupt(void);
+extern asmlinkage void smp_call_function_interrupt(void);
+RTLINUX_EXPORT(smp_reschedule_interrupt);
+RTLINUX_EXPORT(smp_invalidate_interrupt);
+RTLINUX_EXPORT(smp_call_function_interrupt);
+RTLINUX_EXPORT(rtl_reschedule);
+#endif
diff -Nru a/arch/i386/kernel/smp.c b/arch/i386/kernel/smp.c
--- a/arch/i386/kernel/smp.c	Sat May 26 15:03:18 2001
+++ b/arch/i386/kernel/smp.c	Sat May 26 15:03:18 2001
@@ -171,17 +171,6 @@
 		max_cpus = 0;
 }
 
-void ack_APIC_irq(void)
-{
-	/* Clear the IPI */
-
-	/* Dummy read */
-	apic_read(APIC_SPIV);
-
-	/* Docs say use 0 for future compatibility */
-	apic_write(APIC_EOI, 0);
-}
-
 /*
  * Intel MP BIOS table parsing routines:
  */
@@ -756,6 +745,7 @@
 	 */
  	value = apic_read(APIC_LDR);
 	value &= ~APIC_LDR_MASK;
+	value |= (1<<(smp_processor_id()+24));
  	apic_write(APIC_LDR,value);
 
  	value = apic_read(APIC_DFR);
@@ -1755,8 +1745,7 @@
 #if FORCE_APIC_SERIALIZATION
 	unsigned long flags;
 
-	__save_flags(flags);
-	__cli();
+	rtl_hard_local_irq_save_kernel(flags);
 #endif
 
 	/*
@@ -1770,7 +1759,7 @@
 	 */
 	apic_write(APIC_ICR, cfg);
 #if FORCE_APIC_SERIALIZATION
-	__restore_flags(flags);
+	rtl_hard_local_irq_restore_kernel(flags);
 #endif
 }
 
@@ -1904,6 +1893,12 @@
 	send_IPI_single(cpu, RESCHEDULE_VECTOR);
 }
 
+#define RTL_RESCHEDULE_VECTOR 0xEE
+void rtl_reschedule(int cpu)
+{
+	send_IPI_single(cpu, RTL_RESCHEDULE_VECTOR);
+}
+
 /*
  * this function sends a 'stop' IPI to all other CPUs in the system.
  * it goes straight through.
@@ -2128,6 +2123,7 @@
 asmlinkage void smp_stop_cpu_interrupt(void)
 {
 	stop_this_cpu();
+	ack_APIC_irq();
 }
 
 asmlinkage void smp_call_function_interrupt(void)
diff -Nru a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c
--- a/arch/i386/kernel/time.c	Sat May 26 15:03:18 2001
+++ b/arch/i386/kernel/time.c	Sat May 26 15:03:18 2001
@@ -113,7 +113,7 @@
 
 #define TICK_SIZE tick
 
-#ifndef CONFIG_X86_TSC
+/* #ifndef CONFIG_X86_TSC */
 
 spinlock_t i8253_lock = SPIN_LOCK_UNLOCKED;
 
@@ -239,13 +239,13 @@
 	return count;
 }
 
-static unsigned long (*do_gettimeoffset)(void) = do_slow_gettimeoffset;
+unsigned long (*do_gettimeoffset)(void) = do_slow_gettimeoffset;
 
-#else
+/* #else */
 
-#define do_gettimeoffset()	do_fast_gettimeoffset()
+/* #define do_gettimeoffset()	do_fast_gettimeoffset() */
 
-#endif
+/* #endif */
 
 /*
  * This version of gettimeofday has microsecond resolution
@@ -428,7 +428,7 @@
 #endif
 }
 
-static int use_tsc = 0;
+int use_tsc = 0;
 
 /*
  * This is the same as the above, except we _also_ save the current
diff -Nru a/include/asm-i386/apic.h b/include/asm-i386/apic.h
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/include/asm-i386/apic.h	Sat May 26 15:03:18 2001
@@ -0,0 +1,10 @@
+#ifndef __ASM_APIC_H
+#define __ASM_APIC_H
+
+#include <linux/config.h>
+#ifdef CONFIG_X86_LOCAL_API
+#include <asm/fixmap.h>
+#include <asm/i82489.h>
+#include <asm/hw_irq.h>
+#endif
+#endif
diff -Nru a/include/asm-i386/hw_irq.h b/include/asm-i386/hw_irq.h
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/include/asm-i386/hw_irq.h	Sat May 26 15:03:18 2001
@@ -0,0 +1,48 @@
+#ifndef _ASM_HW_IRQ_H
+#define _ASM_HW_IRQ_H
+
+
+#include <linux/config.h>
+
+/*
+ * IRQ line status.
+ */
+#define IRQ_INPROGRESS	1	/* IRQ handler active - do not enter! */
+#define IRQ_DISABLED	2	/* IRQ disabled - do not enter! */
+#define IRQ_PENDING	4	/* IRQ pending - replay on enable */
+#define IRQ_REPLAY	8	/* IRQ has been replayed but not acked yet */
+#define IRQ_AUTODETECT	16	/* IRQ is being autodetected */
+#define IRQ_WAITING	32	/* IRQ not yet seen - for autodetection */
+
+/*
+ * IDT vectors usable for external interrupt sources start
+ * at 0x20:
+ */
+#define FIRST_EXTERNAL_VECTOR	0x20
+
+#define SYSCALL_VECTOR		0x80
+
+/*
+ * Vectors 0x20-0x2f are used for ISA interrupts.
+ */
+
+#define SPURIOUS_APIC_VECTOR	0xff
+#define STOP_CPU_VECTOR		0xfe
+/* ERROR_APIC_VECTOR never used in 2.2 */
+#define ERROR_APIC_VECTOR	0xfe
+#define INVALIDATE_TLB_VECTOR	0xfd
+#define RESCHEDULE_VECTOR	0xfc
+#define CALL_FUNCTION_VECTOR	0xfb
+#define LOCAL_TIMER_VECTOR	0xef
+
+/*
+ * First APIC vector available to drivers: (vectors 0x51-0xfe)
+ */
+#define IRQ0_TRAP_VECTOR	0x31
+
+/*
+ * This IRQ should never happen, but we print a message nevertheless.
+ */
+#define SPURIOUS_APIC_VECTOR	0xff
+
+#endif /* _ASM_HW_IRQ_H */
diff -Nru a/include/asm-i386/i82489.h b/include/asm-i386/i82489.h
--- a/include/asm-i386/i82489.h	Sat May 26 15:03:18 2001
+++ b/include/asm-i386/i82489.h	Sat May 26 15:03:18 2001
@@ -100,4 +100,26 @@
 	return *((volatile unsigned long *)(APIC_BASE+reg));
 }
 
+
+struct __xchg_dummy23 { unsigned long a[100]; };
+#define __xg23(x) ((struct __xchg_dummy23 *)(x))
+
+extern __inline void apic_write0(unsigned long reg)
+{
+	__asm__ __volatile__("xor %%eax, %%eax\n\t"
+			     "xchgl %%eax, %0\n\t"
+				:
+				:"m" (*__xg23(APIC_BASE + reg))
+				:"memory", "ax");
+}
+
+#include <asm/system.h>
+extern inline void ack_APIC_irq(void)
+{
+	/* Clear the IPI */
+
+ 	label_ack_APIC(); /* used to generate RTLinux patch point */
+	apic_write0(APIC_EOI);
+}
+
 #endif
diff -Nru a/include/asm-i386/mmu_context.h b/include/asm-i386/mmu_context.h
--- a/include/asm-i386/mmu_context.h	Sat May 26 15:03:18 2001
+++ b/include/asm-i386/mmu_context.h	Sat May 26 15:03:18 2001
@@ -10,4 +10,20 @@
 #define destroy_context(mm)	do { } while(0)
 #define activate_context(tsk)	do { } while(0)
 
+/* backport of 2.4 stuff for PSC */
+#define active_mm mm
+static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk, unsigned cpu)
+{
+	if (prev != next) {
+		/*
+		 * Re-load LDT if necessary
+		 */
+		if (prev->segments != next->segments)
+			asm volatile("lldt %0": :"g" (*(unsigned short *)&tsk->tss.ldt));
+
+		/* Re-load page tables */
+		asm volatile("movl %0,%%cr3": :"r" (__pa(next->pgd)));
+	}
+}
+
 #endif
diff -Nru a/include/asm-i386/rtlinux.h b/include/asm-i386/rtlinux.h
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/include/asm-i386/rtlinux.h	Sat May 26 15:03:18 2001
@@ -0,0 +1,14 @@
+
+/* RTLinux support for patching the running kernel.
+	* (c) Victor Yodaiken 1999
+*/
+
+#define label_ack_APIC() xlabel_code(0x12344321)
+#define xlabel_code(x) asm __volatile__(".section rtlinux_patch,\"a\"\n .align 4\n"\
+                             ".long 1f,"#x"\n" ".previous\n 1:\n" );
+#define RTLINUX_LABEL(x)\
+  ".section rtlinux_patch,\"a\"\n .align 4\n .long 1f,"#x"\n .previous\n 1:\n"
+
+#define RTLINUX_EXPORT(x)\
+  asm (".section rtlinux_funcs,\"a\"\n .align 4\n"\
+                             ".long "#x"\n .previous\n" );
diff -Nru a/include/asm-i386/rtlinux_cli.h b/include/asm-i386/rtlinux_cli.h
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/include/asm-i386/rtlinux_cli.h	Sat May 26 15:03:18 2001
@@ -0,0 +1,35 @@
+#ifndef RTLINUX_CLI_H
+#define RTLINUX_CLI_H
+
+/* interrupt control.. */
+#define rtl_hard_save_flags_kernel(x)		__asm__ __volatile__("pushfl ; popl %0":"=g" (x): /* no input */ :"memory")
+#define rtl_hard_restore_flags_kernel(x) 	__asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory")
+#define rtl_hard_cli_kernel() 		__asm__ __volatile__("cli": : :"memory")
+#define rtl_hard_sti_kernel()			__asm__ __volatile__("sti": : :"memory")
+
+/* For spinlocks etc */
+#define rtl_hard_local_irq_save_kernel(x)	__asm__ __volatile__("pushfl ; popl %0 ; cli":"=g" (x): /* no input */ :"memory")
+#define rtl_hard_local_irq_restore_kernel(x)	__asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory")
+#define rtl_hard_local_irq_disable_kernel()	__asm__ __volatile__("cli": : :"memory")
+#define rtl_hard_local_irq_enable_kernel()	__asm__ __volatile__("sti": : :"memory")
+struct irq_control_s {
+	void (*do_save_flags)(unsigned long *);
+	void (*do_restore_flags)(unsigned long);
+	void (*do_cli)(void);
+	void (*do_sti)(void);
+	void (*do_local_irq_save)(unsigned long *);
+	void (*do_local_irq_restore)(unsigned long);
+};
+extern struct irq_control_s irq_control;
+#undef __cli()
+#undef __sti()
+#undef __save_flags(x)
+#undef __restore_flags(x)
+#define __save_flags(x)	irq_control.do_save_flags(&x)
+#define __restore_flags(x) irq_control.do_restore_flags(x)	
+#define __cli()		irq_control.do_cli()	
+#define __sti()		irq_control.do_sti()
+
+#undef safe_halt()
+#define safe_halt()	do { __asm__ __volatile__("cli; nop; sti; hlt": : :"memory"); irq_control.do_sti();  } while (0)
+#endif /* RTLINUX_CLI_H */
diff -Nru a/include/asm-i386/smp.h b/include/asm-i386/smp.h
--- a/include/asm-i386/smp.h	Sat May 26 15:03:18 2001
+++ b/include/asm-i386/smp.h	Sat May 26 15:03:18 2001
@@ -209,6 +209,8 @@
 	return GET_APIC_ID(*(unsigned long *)(APIC_BASE+APIC_ID));
 }
 
+#define hw_smp_processor_id() (hard_smp_processor_id())
+
 #endif /* !ASSEMBLY */
 
 #define NO_PROC_ID		0xFF		/* No processor magic marker */
diff -Nru a/include/asm-i386/spinlock.h b/include/asm-i386/spinlock.h
--- a/include/asm-i386/spinlock.h	Sat May 26 15:03:18 2001
+++ b/include/asm-i386/spinlock.h	Sat May 26 15:03:18 2001
@@ -1,6 +1,11 @@
 #ifndef __ASM_SPINLOCK_H
 #define __ASM_SPINLOCK_H
 
+#define BUG() do { \
+	printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
+	__asm__ __volatile__(".byte 0x0f,0x0b"); \
+} while (0)
+
 #ifndef __SMP__
 
 #define DEBUG_SPINLOCKS	0	/* 0 == no debugging, 1 == maintain lock state, 2 == full debug */
diff -Nru a/include/asm-i386/system.h b/include/asm-i386/system.h
--- a/include/asm-i386/system.h	Sat May 26 15:03:18 2001
+++ b/include/asm-i386/system.h	Sat May 26 15:03:18 2001
@@ -3,6 +3,7 @@
 
 #include <linux/kernel.h>
 #include <asm/segment.h>
+#include <asm/rtlinux.h>
 
 #ifdef __KERNEL__
 
@@ -180,6 +181,7 @@
 __asm__ __volatile__("pushfl ; popl %0":"=g" (x): /* no input */ :"memory")
 #define __restore_flags(x) \
 __asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory")
+#include <asm/rtlinux_cli.h>
 
 
 #ifdef __SMP__
diff -Nru a/include/linux/irq.h b/include/linux/irq.h
--- /dev/null	Wed Dec 31 16:00:00 1969
+++ b/include/linux/irq.h	Sat May 26 15:03:18 2001
@@ -0,0 +1,46 @@
+#ifndef _LINUX_IRQ_H__
+#define _LINUX_IRQ_H__
+
+#include <linux/spinlock.h>
+
+#include <asm/irq.h>
+#include <asm/ptrace.h>
+
+/*
+ * Interrupt controller descriptor. This is all we need
+ * to describe about the low-level hardware. 
+ */
+struct hw_interrupt_type {
+	const char * typename;
+	unsigned int (*startup)(unsigned int irq);
+	void (*shutdown)(unsigned int irq);
+	void (*enable)(unsigned int irq);
+	void (*disable)(unsigned int irq);
+	void (*ack)(unsigned int irq);
+	void (*end)(unsigned int irq);
+	void (*set_affinity)(unsigned int irq, unsigned long mask);
+	void (*handle)(unsigned int irq, struct pt_regs * regs);
+};
+
+typedef struct hw_interrupt_type  hw_irq_controller;
+
+/*
+ * This is the "IRQ descriptor", which contains various information
+ * about the irq, including what kind of hardware handling it has,
+ * whether it is disabled etc etc.
+ *
+ * Pad this out to 32 bytes for cache and indexing reasons.
+ */
+typedef struct {
+	unsigned int status;		/* IRQ status */
+	hw_irq_controller *handler;
+	struct irqaction *action;	/* IRQ action list */
+	unsigned int depth;		/* nested irq disables */
+	spinlock_t lock;
+} irq_desc_t;
+
+extern irq_desc_t irq_desc [NR_IRQS];
+
+
+#endif /* __asm_h */
+
diff -Nru a/include/linux/major.h b/include/linux/major.h
--- a/include/linux/major.h	Sat May 26 15:03:18 2001
+++ b/include/linux/major.h	Sat May 26 15:03:18 2001
@@ -122,6 +122,7 @@
 
 #define LVM_CHAR_MAJOR	109	/* Logical Volume Manager */
 
+#define RTF_MAJOR       150
 #define MDISK_MAJOR     95	/* Official assignations from Peter */
 
 #define AURORA_MAJOR 79