Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1132 insertions, 0 deletions

diff --git a/arch/cris/arch-v10/kernel/entry.S b/arch/cris/arch-v10/kernel/entry.S
new file mode 100644
index 0000000..1bc44f4
--- /dev/null
+++ b/arch/cris/arch-v10/kernel/entry.S
@@ -0,0 +1,1132 @@
+/* $Id: entry.S,v 1.23 2004/10/19 13:07:37 starvik Exp $
+ *
+ *  linux/arch/cris/entry.S
+ *
+ *  Copyright (C) 2000, 2001, 2002 Axis Communications AB
+ *
+ *  Authors:	Bjorn Wesen (bjornw@axis.com)
+ *
+ *  $Log: entry.S,v $
+ *  Revision 1.23  2004/10/19 13:07:37  starvik
+ *  Merge of Linux 2.6.9
+ *
+ *  Revision 1.22  2004/06/21 10:29:55  starvik
+ *  Merge of Linux 2.6.7
+ *
+ *  Revision 1.21  2004/06/09 05:30:27  starvik
+ *  Clean up multiple interrupt handling.
+ *    Prevent interrupts from interrupting each other.
+ *    Handle all active interrupts.
+ *
+ *  Revision 1.20  2004/06/08 08:55:32  starvik
+ *  Removed unused code
+ *
+ *  Revision 1.19  2004/06/04 11:56:15  starvik
+ *  Implemented page table lookup for refills in assembler for improved performance.
+ *
+ *  Revision 1.18  2004/05/11 12:28:25  starvik
+ *  Merge of Linux 2.6.6
+ *
+ *  Revision 1.17  2003/09/11 07:29:49  starvik
+ *  Merge of Linux 2.6.0-test5
+ *
+ *  Revision 1.16  2003/07/04 08:27:41  starvik
+ *  Merge of Linux 2.5.74
+ *
+ *  Revision 1.15  2003/04/09 07:32:55  starvik
+ *  resume should return task_struct, not thread_info
+ *
+ *  Revision 1.14  2003/04/09 05:20:44  starvik
+ *  Merge of Linux 2.5.67
+ *
+ *  Revision 1.13  2002/12/11 15:42:02  starvik
+ *  Extracted v10 (ETRAX 100LX) specific stuff from arch/cris/kernel/*.c
+ *
+ *  Revision 1.12  2002/12/10 09:00:10  starvik
+ *  Merge of Linux 2.5.51
+ *
+ *  Revision 1.11  2002/12/05 07:53:10  starvik
+ *  Corrected constants used with btstq
+ *
+ *  Revision 1.10  2002/11/27 08:45:10  starvik
+ *  pid is in task_struct, not thread_info
+ *
+ *  Revision 1.9  2002/11/26 09:52:05  starvik
+ *  Added preemptive kernel scheduling (if CONFIG_PREEMPT)
+ *
+ *  Revision 1.8  2002/11/20 11:56:11  starvik
+ *  Merge of Linux 2.5.48
+ *
+ *  Revision 1.7  2002/11/18 13:02:42  starvik
+ *  Added fourth parameter to do_notify_resume
+ *  Minor cleanup
+ *
+ *  Revision 1.6  2002/11/11 10:37:50  starvik
+ *  Use new asm-offset defines
+ *  Modified for new location of current->work etc
+ *  Removed SYMBOL_NAME from syscalls
+ *  Added some new syscalls
+ *
+ *  Revision 1.5  2002/11/05 06:45:11  starvik
+ *  Merge of Linux 2.5.45
+ *
+ *  Revision 1.4  2002/02/05 15:41:31  bjornw
+ *  Rewritten to conform better to current 2.5 code (similar to arch/i386)
+ *
+ *  Revision 1.3  2002/01/21 15:22:20  bjornw
+ *  NICE_DOGGY fix from 2.4 arch/cris
+ *
+ *  Revision 1.37  2001/12/07 17:03:55  bjornw
+ *  Call a c-hook called watchdog_bite_hook instead of show_registers directly
+ *
+ *  Revision 1.36  2001/11/22 13:36:36  bjornw
+ *  * In ret_from_intr, check regs->dccr for usermode reentrance instead of
+ *    DCCR explicitely (because the latter might not reflect current reality)
+ *  * In mmu_bus_fault, set $r9 _after_ calling the C-code instead of before
+ *    since $r9 is call-clobbered and is potentially needed afterwards
+ *
+ *  Revision 1.35  2001/10/30 17:10:15  bjornw
+ *  Add some syscalls
+ *
+ *  Revision 1.34  2001/10/01 14:45:03  bjornw
+ *  Removed underscores and added register prefixes
+ *
+ *  Revision 1.33  2001/08/21 13:48:01  jonashg
+ *  Added fix by HP to avoid oops when doing a hard_reset_now.
+ *
+ *  Revision 1.32  2001/08/14 04:32:02  hp
+ *  In _resume, add comment why R9 is saved; don't sound like it's call-saved.
+ *
+ *  Revision 1.31  2001/07/25 16:07:42  bjornw
+ *  softirq_active/mask -> softirq_pending only
+ *
+ *  Revision 1.30  2001/07/05 01:03:32  hp
+ *  - include asm/errno.h to get ENOSYS.
+ *  - Use ENOSYS, not local constant LENOSYS; tweak comments.
+ *  - Explain why .include, not #include is used.
+ *  - Make oops-register-dump if watchdog bits and it's not expected.
+ *  - Don't jsr, use jump _hard_reset_now, and skip spurious nop.
+ *  - Use correct section attribute for section .rodata.
+ *  - Adjust sys_ni_syscall fill number.
+ *
+ *  Revision 1.29  2001/06/25 14:07:00  hp
+ *  	Fix review comment.
+ *  	* head.S: Use IO_STATE, IO_FIELD and IO_MASK constructs instead of
+ *  	magic numbers.  Add comment that -traditional must not be used.
+ *  	* entry.S (SYMBOL_NAME): Change redefinition to use ## concatenation.
+ *  	Correct and update comment.
+ *  	* Makefile (.S.o): Don't use -traditional.  Add comment why the
+ *  	toplevel rule can't be used (now that there's a reason).
+ *
+ *  Revision 1.28  2001/06/21 02:00:40  hp
+ *  	* entry.S: Include asm/unistd.h.
+ *  	(_sys_call_table): Use section .rodata, not .data.
+ *  	(_kernel_thread): Move from...
+ *  	* process.c: ... here.
+ *  	* entryoffsets.c (VAL): Break out from...
+ *  	(OF): Use VAL.
+ *  	(LCLONE_VM): New asmified value from CLONE_VM.
+ *
+ *  Revision 1.27  2001/05/29 11:25:27  markusl
+ *  In case of "spurious_interrupt", do hard_reset instead of hanging system in a loop...
+ *
+ *  Revision 1.26  2001/05/15 15:46:03  bjornw
+ *  Include config.h now that we use some CONFIG_ options
+ *
+ *  Revision 1.25  2001/05/15 05:38:47  hp
+ *  Tweaked code in _ret_from_sys_call
+ *
+ *  Revision 1.24  2001/05/15 05:27:49  hp
+ *  Save r9 in r1 over function call rather than on stack.
+ *
+ *  Revision 1.23  2001/05/15 05:10:00  hp
+ *  Generate entry.S structure offsets from C
+ *
+ *  Revision 1.22  2001/04/17 13:58:39  orjanf
+ *  * Renamed CONFIG_KGDB to CONFIG_ETRAX_KGDB.
+ *
+ *  Revision 1.21  2001/04/17 11:33:29  orjanf
+ *  Updated according to review:
+ *  * Included asm/sv_addr_ag.h to get macro for internal register.
+ *  * Corrected comment regarding system call argument passing.
+ *  * Removed comment about instruction being in a delay slot.
+ *  * Added comment about SYMBOL_NAME macro.
+ *
+ *  Revision 1.20  2001/04/12 08:51:07  hp
+ *  - Add entry for sys_fcntl64.  In fact copy last piece from i386 including ...
+ *  - .rept to fill table to safe state with sys_ni_syscall.
+ *
+ *  Revision 1.19  2001/04/04 09:43:32  orjanf
+ *  * Moved do_sigtrap from traps.c to entry.S.
+ *  * LTASK_PID need not be global anymore.
+ *
+ *  Revision 1.18  2001/03/26 09:25:02  markusl
+ *  Updated after review, should now handle USB interrupts correctly.
+ *
+ *  Revision 1.17  2001/03/21 16:12:55  bjornw
+ *  * Always make room for the cpu status record in the frame, in order to
+ *    use the same framelength and layout for both mmu busfaults and normal
+ *    irqs. No need to check for the explicit CRIS_FRAME_FIXUP type anymore.
+ *  * Fixed bug with using addq for popping the stack in the epilogue - it
+ *    destroyed the flag register. Use instructions that don't affect the
+ *    flag register instead.
+ *  * Removed write to R_PORT_PA_DATA during spurious_interrupt
+ *
+ *  Revision 1.16  2001/03/20 19:43:02  bjornw
+ *  * Get rid of esp0 setting
+ *  * Give a 7th argument to a systemcall - the stackframe
+ *
+ *  Revision 1.15  2001/03/05 13:14:30  bjornw
+ *  Spelling fix
+ *
+ *  Revision 1.14  2001/02/23 08:36:36  perf
+ *  New ABI; syscallnr=r9, arg5=mof, arg6=srp.
+ *  Corrected tracesys call check.
+ *
+ *  Revision 1.13  2001/02/15 08:40:55  perf
+ *  H-P by way of perf;
+ *  - (_system_call): Don't read system call function address into r1.
+ *  - (RBFExit): There is no such thing as a null pop.  Adjust sp by addq.
+ *  - (_system_call): Don't use r10 and don't save and restore it.
+ *  - (THREAD_ESP0): New constant.
+ *  - (_system_call): Inline set_esp0.
+ *
+ *  Revision 1.12  2001/01/31 17:56:25  orjanf
+ *  Added definition of LTASK_PID and made it global.
+ *
+ *  Revision 1.11  2001/01/10 21:13:29  bjornw
+ *  SYMBOL_NAME is defined incorrectly for the compiler options we currently use
+ *
+ *  Revision 1.10  2000/12/18 23:47:56  bjornw
+ *  * Added syscall trace support (ptrace), completely untested of course
+ *  * Removed redundant check for NULL entries in syscall_table
+ *
+ *  Revision 1.9  2000/11/21 16:40:51  bjornw
+ *  * New frame type used when an SBFS frame needs to be popped without
+ *    actually restarting the instruction
+ *  * Enable interrupts in signal_return (they did so in x86, I hope it's a good
+ *    idea)
+ *
+ *  Revision 1.8  2000/11/17 16:53:35  bjornw
+ *  Added detection of frame-type in Rexit, so that mmu_bus_fault can
+ *  use ret_from_intr in the return-path to check for signals (like SEGV)
+ *  and other foul things that might have occurred during the fault.
+ *
+ *  Revision 1.7  2000/10/06 15:04:28  bjornw
+ *  Include mof in register savings
+ *
+ *  Revision 1.6  2000/09/12 16:02:44  bjornw
+ *  Linux-2.4.0-test7 derived updates
+ *
+ *  Revision 1.5  2000/08/17 15:35:15  bjornw
+ *  2.4.0-test6 changed local_irq_count and friends API
+ *
+ *  Revision 1.4  2000/08/02 13:59:30  bjornw
+ *  Removed olduname and uname from the syscall list
+ *
+ *  Revision 1.3  2000/07/31 13:32:58  bjornw
+ *  * Export ret_from_intr
+ *  * _resume updated (prev/last tjohejsan)
+ *  * timer_interrupt obsolete
+ *  * SIGSEGV detection in mmu_bus_fault temporarily disabled
+ *
+ *
+ */
+
+/*
+ * entry.S contains the system-call and fault low-level handling routines.
+ *
+ * NOTE: This code handles signal-recognition, which happens every time
+ * after a timer-interrupt and after each system call.
+ *
+ * Stack layout in 'ret_from_system_call':
+ * 	ptrace needs to have all regs on the stack.
+ *	if the order here is changed, it needs to be 
+ *	updated in fork.c:copy_process, signal.c:do_signal,
+ *	ptrace.c and ptrace.h
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/linkage.h>
+#include <linux/sys.h>
+#include <asm/unistd.h>
+#include <asm/arch/sv_addr_ag.h>
+#include <asm/errno.h>
+#include <asm/thread_info.h>
+#include <asm/arch/offset.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+	;; functions exported from this file
+	
+	.globl system_call
+	.globl ret_from_intr
+	.globl ret_from_fork
+	.globl resume
+	.globl multiple_interrupt
+	.globl hwbreakpoint
+	.globl IRQ1_interrupt
+	.globl spurious_interrupt
+	.globl hw_bp_trigs
+	.globl mmu_bus_fault
+	.globl do_sigtrap
+	.globl gdb_handle_breakpoint
+	.globl sys_call_table
+	
+	;; below are various parts of system_call which are not in the fast-path
+	
+#ifdef CONFIG_PREEMPT	
+	; Check if preemptive kernel scheduling should be done
+_resume_kernel:
+	; Load current task struct
+	movs.w	-8192, $r0	;  THREAD_SIZE = 8192
+	and.d	$sp, $r0
+	move.d	[$r0+TI_preempt_count], $r10	;  Preemption disabled?
+	bne	_Rexit
+	nop
+_need_resched:
+	move.d	[$r0+TI_flags], $r10
+	btstq	TIF_NEED_RESCHED, $r10	; Check if need_resched is set
+	bpl	_Rexit
+	nop
+	; Ok, lets's do some preemptive kernel scheduling
+	move.d	PREEMPT_ACTIVE, $r10
+	move.d	$r10, [$r0+TI_preempt_count] ; Mark as active
+	ei
+	jsr	schedule
+	clear.d	[$r0+TI_preempt_count] ;  Mark as inactive
+	di
+	; Load new task struct
+	movs.w	-8192, $r0	;  THREAD_SIZE = 8192
+	and.d	$sp, $r0
+	; One more time (with new task)
+	ba	_need_resched
+	nop
+#else
+#define _resume_kernel _Rexit
+#endif	
+
+	; Called at exit from fork. schedule_tail must be called to drop
+	; spinlock if CONFIG_PREEMPT
+ret_from_fork:
+	jsr schedule_tail
+	ba  ret_from_sys_call
+	nop
+		
+ret_from_intr:
+	;; check for resched if preemptive kernel or if we're going back to user-mode 
+	;; this test matches the user_regs(regs) macro
+	;; we cannot simply test $dccr, because that does not necessarily
+	;; reflect what mode we'll return into.
+	
+	move.d	[$sp + PT_dccr], $r0; regs->dccr
+	btstq	8, $r0		; U-flag
+	bpl     _resume_kernel
+	; Note that di below is in delay slot 
+	
+_resume_userspace:
+	di			; so need_resched and sigpending don't change
+
+	movs.w	-8192, $r0	; THREAD_SIZE == 8192
+	and.d	$sp, $r0
+
+	move.d	[$r0+TI_flags], $r10	; current->work
+	and.d	_TIF_WORK_MASK, $r10	; is there any work to be done on return
+	bne	_work_pending
+	nop
+	ba	_Rexit
+	nop
+	
+	;; The system_call is called by a BREAK instruction, which works like
+	;; an interrupt call but it stores the return PC in BRP instead of IRP.
+	;; Since we dont really want to have two epilogues (one for system calls
+	;; and one for interrupts) we push the contents of BRP instead of IRP in the
+	;; system call prologue, to make it look like an ordinary interrupt on the
+	;; stackframe.
+	;;
+	;; Since we can't have system calls inside interrupts, it should not matter
+	;; that we don't stack IRP.
+	;; 
+	;; In r9 we have the wanted syscall number. Arguments come in r10,r11,r12,r13,mof,srp
+	;;
+	;; This function looks on the _surface_ like spaghetti programming, but it's
+	;; really designed so that the fast-path does not force cache-loading of non-used
+	;; instructions. Only the non-common cases cause the outlined code to run..
+
+system_call:
+	;; stack-frame similar to the irq heads, which is reversed in ret_from_sys_call
+	move	$brp,[$sp=$sp-16]; instruction pointer and room for a fake SBFS frame
+	push	$srp
+	push	$dccr
+	push	$mof
+	subq	14*4, $sp		; make room for r0-r13
+	movem	$r13, [$sp]	; push r0-r13
+	push	$r10		; push orig_r10
+	clear.d [$sp=$sp-4]	; frametype == 0, normal stackframe
+	
+	movs.w	-ENOSYS, $r0
+	move.d	$r0, [$sp+PT_r10]	; put the default return value in r10 in the frame
+
+	;; check if this process is syscall-traced
+
+	movs.w	-8192, $r0	; THREAD_SIZE == 8192
+	and.d	$sp, $r0
+	
+	move.d	[$r0+TI_flags], $r0
+	btstq   TIF_SYSCALL_TRACE, $r0
+	bmi	_syscall_trace_entry
+	nop	
+
+_syscall_traced:	
+
+	;; check for sanity in the requested syscall number
+	
+	cmpu.w	NR_syscalls, $r9	
+	bcc	ret_from_sys_call
+	lslq	2, $r9		;  multiply by 4, in the delay slot
+
+	;; as a bonus 7th parameter, we give the location on the stack
+	;; of the register structure itself. some syscalls need this.
+
+	push	$sp
+	
+	;; the parameter carrying registers r10, r11, r12 and 13 are intact.
+	;; the fifth and sixth parameters (if any) was in mof and srp 
+	;; respectively, and we need to put them on the stack.
+
+	push	$srp
+	push	$mof
+	
+	jsr	[$r9+sys_call_table]	; actually do the system call
+	addq	3*4, $sp		; pop the mof, srp and regs parameters
+	move.d	$r10, [$sp+PT_r10]	; save the return value
+
+	moveq	1, $r9		; "parameter" to ret_from_sys_call to show it was a sys call
+	
+	;; fall through into ret_from_sys_call to return
+	
+ret_from_sys_call:
+	;; r9 is a parameter - if >=1 we came from a syscall, if 0, from an irq
+		
+	;; get the current task-struct pointer (see top for defs)
+
+	movs.w	-8192, $r0	; THREAD_SIZE == 8192 
+	and.d	$sp, $r0
+
+	di			; make sure need_resched and sigpending don't change
+	move.d	[$r0+TI_flags],$r1
+	and.d	_TIF_ALLWORK_MASK, $r1
+	bne	_syscall_exit_work
+	nop
+
+_Rexit:
+	;; this epilogue MUST match the prologues in multiple_interrupt, irq.h and ptregs.h
+	pop	$r10		; frametype
+	bne	_RBFexit	; was not CRIS_FRAME_NORMAL, handle otherwise
+	addq	4, $sp		; skip orig_r10, in delayslot
+	movem	[$sp+], $r13	; registers r0-r13
+	pop	$mof		; multiply overflow register 
+	pop	$dccr		; condition codes
+	pop	$srp		; subroutine return pointer
+	;; now we have a 4-word SBFS frame which we do not want to restore
+	;; using RBF since it was not stacked with SBFS. instead we would like to
+	;; just get the PC value to restart it with, and skip the rest of
+	;; the frame.
+	;; Also notice that it's important to use instructions here that
+	;; keep the interrupts disabled (since we've already popped DCCR)
+	move	[$sp=$sp+16], $p8; pop the SBFS frame from the sp
+	jmpu	[$sp-16]	; return through the irp field in the sbfs frame
+
+_RBFexit:
+	movem	[$sp+], $r13	; registers r0-r13, in delay slot
+	pop	$mof		; multiply overflow register 
+	pop	$dccr		; condition codes
+	pop	$srp		; subroutine return pointer
+	rbf	[$sp+]		; return by popping the CPU status
+
+	;; We get here after doing a syscall if extra work might need to be done
+	;; perform syscall exit tracing if needed
+	
+_syscall_exit_work:
+	;; $r0 contains current at this point and irq's are disabled
+
+	move.d  [$r0+TI_flags], $r1
+	btstq	TIF_SYSCALL_TRACE, $r1
+	bpl	_work_pending
+	nop
+	
+	ei
+
+	move.d	$r9, $r1	; preserve r9
+	jsr	do_syscall_trace
+	move.d	$r1, $r9
+	
+	ba	_resume_userspace
+	nop
+	
+_work_pending:
+	move.d  [$r0+TI_flags], $r1
+	btstq   TIF_NEED_RESCHED, $r1
+	bpl	_work_notifysig	; was neither trace nor sched, must be signal/notify
+	nop
+	
+_work_resched:
+	move.d	$r9, $r1	; preserve r9
+	jsr	schedule
+	move.d	$r1, $r9
+	di
+
+	move.d	[$r0+TI_flags], $r1
+	and.d	_TIF_WORK_MASK, $r1; ignore the syscall trace counter
+	beq	_Rexit
+	nop
+	btstq	TIF_NEED_RESCHED, $r1
+	bmi	_work_resched	; current->work.need_resched
+	nop
+
+_work_notifysig:
+	;; deal with pending signals and notify-resume requests
+
+	move.d	$r9, $r10	; do_notify_resume syscall/irq param
+	moveq	0, $r11		; oldset param - 0 in this case
+	move.d	$sp, $r12	; the regs param
+	move.d  $r1, $r13	; the thread_info_flags parameter
+	jsr	do_notify_resume
+	
+	ba _Rexit
+	nop
+
+	;; We get here as a sidetrack when we've entered a syscall with the
+	;; trace-bit set. We need to call do_syscall_trace and then continue
+	;; with the call.
+	
+_syscall_trace_entry:
+	;; PT_r10 in the frame contains -ENOSYS as required, at this point
+	
+	jsr	do_syscall_trace
+
+	;; now re-enter the syscall code to do the syscall itself
+	;; we need to restore $r9 here to contain the wanted syscall, and
+	;; the other parameter-bearing registers
+
+	move.d	[$sp+PT_r9], $r9
+	move.d	[$sp+PT_orig_r10], $r10  ; PT_r10 is already filled with -ENOSYS.
+	move.d	[$sp+PT_r11],      $r11
+	move.d	[$sp+PT_r12],      $r12
+	move.d	[$sp+PT_r13],      $r13
+	move	[$sp+PT_mof],      $mof
+	move	[$sp+PT_srp],      $srp
+	
+	ba	_syscall_traced
+	nop
+	
+	;; resume performs the actual task-switching, by switching stack pointers
+	;; input arguments: r10 = prev, r11 = next, r12 = thread offset in task struct
+	;; returns old current in r10
+	;;
+	;; TODO:  see the i386 version. The switch_to which calls resume in our version
+	;;        could really be an inline asm of this.
+
+resume:	
+	push	$srp		         ; we keep the old/new PC on the stack 
+	add.d	$r12, $r10		 ; r10 = current tasks tss
+	move	$dccr, [$r10+THREAD_dccr]; save irq enable state
+	di
+
+	move	$usp, [$r10+ THREAD_usp] ; save user-mode stackpointer
+	
+	;; See copy_thread for the reason why register R9 is saved.
+	subq	10*4, $sp
+	movem	$r9, [$sp]		 ; save non-scratch registers and R9.
+	
+	move.d	$sp, [$r10+THREAD_ksp]	 ; save the kernel stack pointer for the old task
+	move.d	$sp, $r10		 ; return last running task in r10
+	and.d   -8192, $r10	         ; get thread_info from stackpointer
+	move.d  [$r10+TI_task], $r10     ; get task  
+	add.d	$r12, $r11		 ; find the new tasks tss
+	move.d	[$r11+THREAD_ksp], $sp	 ; switch into the new stackframe by restoring kernel sp
+
+	movem	[$sp+], $r9		 ; restore non-scratch registers and R9.
+
+	move	[$r11+THREAD_usp], $usp ; restore user-mode stackpointer
+	
+	move	[$r11+THREAD_dccr], $dccr ; restore irq enable status
+	jump	[$sp+]		         ; restore PC
+
+	;; This is the MMU bus fault handler.
+	;; It needs to stack the CPU status and overall is different
+	;; from the other interrupt handlers.
+
+mmu_bus_fault:
+	;; For refills we try to do a quick page table lookup. If it is
+	;; a real fault we let the mm subsystem handle it.
+
+	;; the first longword in the sbfs frame was the interrupted PC
+	;; which fits nicely with the "IRP" slot in pt_regs normally used to
+	;; contain the return address. used by Oops to print kernel errors.
+	sbfs	[$sp=$sp-16]	; push the internal CPU status
+	push	$dccr
+	di
+	subq	2*4, $sp
+	movem	$r1, [$sp]
+	move.d  [R_MMU_CAUSE], $r1
+	;; ETRAX 100LX TR89 bugfix: if the second half of an unaligned
+	;; write causes a MMU-fault, it will not be restarted correctly.
+	;; This could happen if a write crosses a page-boundary and the
+	;; second page is not yet COW'ed or even loaded. The workaround
+	;; is to clear the unaligned bit in the CPU status record, so
+	;; that the CPU will rerun both the first and second halves of
+	;; the instruction. This will not have any sideeffects unless
+	;; the first half goes to any device or memory that can't be
+	;; written twice, and which is mapped through the MMU.
+	;;
+	;; We only need to do this for writes.
+	btstq	8, $r1		   ; Write access?
+	bpl	1f
+	nop
+	move.d	[$sp+16], $r0	   ; Clear unaligned bit in csrinstr
+	and.d	~(1<<5), $r0
+	move.d	$r0, [$sp+16]
+1:	btstq	12, $r1		   ; Refill?
+	bpl	2f
+	lsrq	PMD_SHIFT, $r1     ; Get PMD index into PGD (bit 24-31)
+	move.d  [current_pgd], $r0 ; PGD for the current process
+	move.d	[$r0+$r1.d], $r0   ; Get PMD
+	beq	2f
+	nop
+	and.w	PAGE_MASK, $r0	   ; Remove PMD flags
+	move.d  [R_MMU_CAUSE], $r1
+	lsrq	PAGE_SHIFT, $r1
+	and.d	0x7ff, $r1         ; Get PTE index into PMD (bit 13-24)
+	move.d	[$r0+$r1.d], $r1   ; Get PTE
+	beq	2f
+	nop
+	;; Store in TLB
+	move.d  $r1, [R_TLB_LO]
+	;; Return
+	movem	[$sp+], $r1
+	pop	$dccr
+	rbf	[$sp+]		; return by popping the CPU status
+
+2:	; PMD or PTE missing, let the mm subsystem fix it up.
+	movem	[$sp+], $r1
+	pop	$dccr
+
+	; Ok, not that easy, pass it on to the mm subsystem
+	; The MMU status record is now on the stack
+	push	$srp		; make a stackframe similar to pt_regs
+	push	$dccr
+	push	$mof
+	di
+	subq	14*4, $sp
+	movem	$r13, [$sp]
+	push	$r10		; dummy orig_r10
+	moveq	1, $r10
+	push	$r10		; frametype == 1, BUSFAULT frame type
+
+	move.d	$sp, $r10	; pt_regs argument to handle_mmu_bus_fault
+		
+	jsr	handle_mmu_bus_fault  ; in arch/cris/arch-v10/mm/fault.c
+
+	;; now we need to return through the normal path, we cannot just
+	;; do the RBFexit since we might have killed off the running
+	;; process due to a SEGV, scheduled due to a page blocking or
+	;; whatever.
+
+	moveq	0, $r9		; busfault is equivalent to an irq
+		
+	ba	ret_from_intr
+	nop
+		
+	;; special handlers for breakpoint and NMI
+hwbreakpoint:
+	push	$dccr
+	di
+	push	$r10
+	push	$r11
+	move.d	[hw_bp_trig_ptr],$r10
+	move	$brp,$r11
+	move.d	$r11,[$r10+]
+	move.d	$r10,[hw_bp_trig_ptr]
+1:	pop	$r11
+	pop	$r10
+	pop	$dccr
+	retb
+	nop
+	
+IRQ1_interrupt:
+
+#if defined(CONFIG_ETRAX_WATCHDOG) && !defined(CONFIG_SVINTO_SIM)
+;; If we receive a watchdog interrupt while it is not expected, then set
+;; up a canonical frame and dump register contents before dying.
+
+	;; this prologue MUST match the one in irq.h and the struct in ptregs.h!!!
+	move	$brp,[$sp=$sp-16]; instruction pointer and room for a fake SBFS frame
+	push	$srp
+	push	$dccr
+	push	$mof
+	di
+	subq	14*4, $sp
+	movem	$r13, [$sp]
+	push	$r10		; push orig_r10
+	clear.d [$sp=$sp-4]	; frametype == 0, normal frame
+
+;; We don't check that we actually were bit by the watchdog as opposed to
+;; an external NMI, since there is currently no handler for external NMI.
+
+;; Check if we're waiting for reset to happen, as signalled by
+;; hard_reset_now setting cause_of_death to a magic value.  If so, just
+;; get stuck until reset happens.
+	.comm	cause_of_death, 4	;; Don't declare this anywhere.
+	move.d	[cause_of_death], $r10
+	cmp.d	0xbedead, $r10
+_killed_by_death:
+	beq	_killed_by_death
+	nop
+
+;; We'll see this in ksymoops dumps.
+Watchdog_bite:
+
+#ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
+       ;; We just restart the watchdog here to be sure we dont get
+       ;; hit while printing the watchdogmsg below
+       ;; This restart is compatible with the rest of the C-code, so
+       ;; the C-code can keep restarting the watchdog after this point.
+       ;; The non-NICE_DOGGY code below though, disables the possibility
+       ;; to restart since it changes the watchdog key, to avoid any
+       ;; buggy loops etc. keeping the watchdog alive after this.
+       jsr     reset_watchdog
+#else
+
+;; We need to extend the 3.3ms after the NMI at watchdog bite, so we have
+;; time for an oops-dump over a 115k2 serial wire.  Another 100ms should do.
+
+;; Change the watchdog key to an arbitrary 3-bit value and restart the
+;; watchdog.
+#define WD_INIT 2
+	moveq	  IO_FIELD (R_WATCHDOG, key, WD_INIT), $r10
+	move.d	R_WATCHDOG, $r11
+
+	move.d	$r10, [$r11]
+	moveq	  IO_FIELD (R_WATCHDOG, key,				\
+			    IO_EXTRACT (R_WATCHDOG, key,		\
+					IO_MASK (R_WATCHDOG, key))	\
+			    ^ WD_INIT)					\
+		| IO_STATE (R_WATCHDOG, enable, start), $r10
+	move.d	$r10, [$r11]
+
+#endif
+	
+;; Note that we don't do "setf m" here (or after two necessary NOPs),
+;; since *not* doing that saves us from re-entrancy checks.  We don't want
+;; to get here again due to possible subsequent NMIs; we want the watchdog
+;; to reset us.
+
+	move.d	_watchdogmsg,$r10
+	jsr	printk
+
+	move.d	$sp, $r10
+	jsr	watchdog_bite_hook
+
+;; This nop is here so we see the "Watchdog_bite" label in ksymoops dumps
+;; rather than "spurious_interrupt".
+	nop
+;; At this point we drop down into spurious_interrupt, which will do a
+;; hard reset.
+
+	.section .rodata,"a"
+_watchdogmsg:
+	.ascii	"Oops: bitten by watchdog\n\0"
+	.previous
+
+#endif /* CONFIG_ETRAX_WATCHDOG and not CONFIG_SVINTO_SIM */
+
+spurious_interrupt:	
+	di
+	jump hard_reset_now
+
+	;; this handles the case when multiple interrupts arrive at the same time
+	;; we jump to the first set interrupt bit in a priority fashion
+	;; the hardware will call the unserved interrupts after the handler finishes
+	
+multiple_interrupt:
+	;; this prologue MUST match the one in irq.h and the struct in ptregs.h!!!
+	move	$irp,[$sp=$sp-16]; instruction pointer and room for a fake SBFS frame
+	push	$srp
+	push	$dccr
+	push	$mof
+	di
+	subq	14*4, $sp
+	movem	$r13, [$sp]
+	push	$r10		; push orig_r10
+	clear.d [$sp=$sp-4]	; frametype == 0, normal frame
+	
+	moveq	2, $r2		; first bit we care about is the timer0 irq
+	move.d	[R_VECT_MASK_RD], $r0; read the irq bits that triggered the multiple irq
+	move.d	$r0, [R_VECT_MASK_CLR] ; Block all active IRQs
+1:	
+	btst	$r2, $r0	; check for the irq given by bit r2
+	bpl	2f
+	move.d  $r2, $r10	; First argument to do_IRQ
+	move.d  $sp, $r11	; second argument to do_IRQ
+	jsr	do_IRQ
+2:
+	addq	1, $r2		; next vector bit
+	cmp.b	32, $r2
+	bne	1b	; process all irq's up to and including number 31
+	moveq	0, $r9  ; make ret_from_intr realise we came from an ir
+	
+	move.d	$r0, [R_VECT_MASK_SET] ;  Unblock all the IRQs
+	jump    ret_from_intr
+
+do_sigtrap:
+	;; 
+	;; SIGTRAP the process that executed the break instruction.
+	;; Make a frame that Rexit in entry.S expects.
+	;;
+	move	$brp, [$sp=$sp-16]	; Push BRP while faking a cpu status record.
+	push	$srp			; Push subroutine return pointer.
+	push	$dccr			; Push condition codes.
+	push	$mof			; Push multiply overflow reg.
+	di				; Need to disable irq's at this point.
+	subq	14*4, $sp		; Make room for r0-r13.
+	movem	$r13, [$sp]		; Push the r0-r13 registers.
+	push	$r10			; Push orig_r10.
+	clear.d	[$sp=$sp-4]		; Frametype - this is a normal stackframe.
+
+	movs.w	-8192,$r9		; THREAD_SIZE == 8192
+	and.d	$sp, $r9
+	move.d  [$r9+TI_task], $r10
+	move.d  [$r10+TASK_pid], $r10	; current->pid as arg1. 
+	moveq	5, $r11			; SIGTRAP as arg2.
+	jsr	sys_kill       
+	jump	ret_from_intr		; Use the return routine for interrupts.
+
+gdb_handle_breakpoint:	
+	push	$dccr
+	push	$r0
+#ifdef CONFIG_ETRAX_KGDB
+	move	$dccr, $r0		; U-flag not affected by previous insns. 
+	btstq	8, $r0			; Test the U-flag.
+	bmi	_ugdb_handle_breakpoint	; Go to user mode debugging. 
+	nop				; Empty delay slot (cannot pop r0 here). 
+	pop	$r0			; Restore r0.
+	ba	kgdb_handle_breakpoint	; Go to kernel debugging. 
+	pop	$dccr			; Restore dccr in delay slot.
+#endif
+	
+_ugdb_handle_breakpoint:	
+	move	$brp, $r0		; Use r0 temporarily for calculation.
+	subq	2, $r0			; Set to address of previous instruction.
+	move	$r0, $brp
+	pop	$r0			; Restore r0. 
+	ba	do_sigtrap		; SIGTRAP the offending process. 
+	pop	$dccr			; Restore dccr in delay slot.
+	
+	.data
+
+hw_bp_trigs:
+	.space 64*4
+hw_bp_trig_ptr:
+	.dword hw_bp_trigs
+
+	.section .rodata,"a"
+sys_call_table:	
+	.long sys_restart_syscall	/* 0 - old "setup()" system call, used for restarting */
+	.long sys_exit
+	.long sys_fork
+	.long sys_read
+	.long sys_write
+	.long sys_open		/* 5 */
+	.long sys_close
+	.long sys_waitpid
+	.long sys_creat
+	.long sys_link
+	.long sys_unlink	/* 10 */
+	.long sys_execve
+	.long sys_chdir
+	.long sys_time
+	.long sys_mknod
+	.long sys_chmod		/* 15 */
+	.long sys_lchown16
+	.long sys_ni_syscall	/* old break syscall holder */
+	.long sys_stat
+	.long sys_lseek
+	.long sys_getpid	/* 20 */
+	.long sys_mount
+	.long sys_oldumount
+	.long sys_setuid16
+	.long sys_getuid16
+	.long sys_stime		/* 25 */
+	.long sys_ptrace
+	.long sys_alarm
+	.long sys_fstat
+	.long sys_pause
+	.long sys_utime		/* 30 */
+	.long sys_ni_syscall	/* old stty syscall holder */
+	.long sys_ni_syscall	/* old gtty syscall holder */
+	.long sys_access
+	.long sys_nice
+	.long sys_ni_syscall	/* 35  old ftime syscall holder */
+	.long sys_sync
+	.long sys_kill
+	.long sys_rename
+	.long sys_mkdir
+	.long sys_rmdir		/* 40 */
+	.long sys_dup
+	.long sys_pipe
+	.long sys_times
+	.long sys_ni_syscall	/* old prof syscall holder */
+	.long sys_brk		/* 45 */
+	.long sys_setgid16
+	.long sys_getgid16
+	.long sys_signal
+	.long sys_geteuid16
+	.long sys_getegid16	/* 50 */
+	.long sys_acct
+	.long sys_umount	/* recycled never used phys( */
+	.long sys_ni_syscall	/* old lock syscall holder */
+	.long sys_ioctl
+	.long sys_fcntl		/* 55 */
+	.long sys_ni_syscall	/* old mpx syscall holder */
+	.long sys_setpgid
+	.long sys_ni_syscall	/* old ulimit syscall holder */
+	.long sys_ni_syscall	/* old sys_olduname holder */
+	.long sys_umask		/* 60 */
+	.long sys_chroot
+	.long sys_ustat
+	.long sys_dup2
+	.long sys_getppid
+	.long sys_getpgrp	/* 65 */
+	.long sys_setsid
+	.long sys_sigaction
+	.long sys_sgetmask
+	.long sys_ssetmask
+	.long sys_setreuid16	/* 70 */
+	.long sys_setregid16
+	.long sys_sigsuspend
+	.long sys_sigpending
+	.long sys_sethostname
+	.long sys_setrlimit	/* 75 */
+	.long sys_old_getrlimit
+	.long sys_getrusage
+	.long sys_gettimeofday
+	.long sys_settimeofday
+	.long sys_getgroups16	/* 80 */
+	.long sys_setgroups16
+	.long sys_select	/* was old_select in Linux/E100 */
+	.long sys_symlink
+	.long sys_lstat
+	.long sys_readlink	/* 85 */
+	.long sys_uselib
+	.long sys_swapon
+	.long sys_reboot
+	.long old_readdir
+	.long old_mmap		/* 90 */
+	.long sys_munmap
+	.long sys_truncate
+	.long sys_ftruncate
+	.long sys_fchmod
+	.long sys_fchown16	/* 95 */
+	.long sys_getpriority
+	.long sys_setpriority
+	.long sys_ni_syscall	/* old profil syscall holder */
+	.long sys_statfs
+	.long sys_fstatfs	/* 100 */
+	.long sys_ni_syscall	/* sys_ioperm in i386 */
+	.long sys_socketcall
+	.long sys_syslog
+	.long sys_setitimer
+	.long sys_getitimer	/* 105 */
+	.long sys_newstat
+	.long sys_newlstat
+	.long sys_newfstat
+	.long sys_ni_syscall	/* old sys_uname holder */
+	.long sys_ni_syscall	/* sys_iopl in i386 */
+	.long sys_vhangup
+	.long sys_ni_syscall	/* old "idle" system call */
+	.long sys_ni_syscall	/* vm86old in i386 */
+	.long sys_wait4
+	.long sys_swapoff	/* 115 */
+	.long sys_sysinfo
+	.long sys_ipc
+	.long sys_fsync
+	.long sys_sigreturn
+	.long sys_clone		/* 120 */
+	.long sys_setdomainname
+	.long sys_newuname
+	.long sys_ni_syscall	/* sys_modify_ldt */
+	.long sys_adjtimex
+	.long sys_mprotect	/* 125 */
+	.long sys_sigprocmask
+	.long sys_ni_syscall	/* old "create_module" */ 
+	.long sys_init_module
+	.long sys_delete_module
+	.long sys_ni_syscall	/* 130:	old "get_kernel_syms" */
+	.long sys_quotactl
+	.long sys_getpgid
+	.long sys_fchdir
+	.long sys_bdflush
+	.long sys_sysfs		/* 135 */
+	.long sys_personality
+	.long sys_ni_syscall	/* for afs_syscall */
+	.long sys_setfsuid16
+	.long sys_setfsgid16
+	.long sys_llseek	/* 140 */
+	.long sys_getdents
+	.long sys_select
+	.long sys_flock
+	.long sys_msync
+	.long sys_readv		/* 145 */
+	.long sys_writev
+	.long sys_getsid
+	.long sys_fdatasync
+	.long sys_sysctl
+	.long sys_mlock		/* 150 */
+	.long sys_munlock
+	.long sys_mlockall
+	.long sys_munlockall
+	.long sys_sched_setparam
+	.long sys_sched_getparam	/* 155 */
+	.long sys_sched_setscheduler
+	.long sys_sched_getscheduler
+	.long sys_sched_yield
+	.long sys_sched_get_priority_max
+	.long sys_sched_get_priority_min	/* 160 */
+	.long sys_sched_rr_get_interval
+	.long sys_nanosleep
+	.long sys_mremap
+	.long sys_setresuid16
+	.long sys_getresuid16	/* 165 */
+	.long sys_ni_syscall	/* sys_vm86 */
+	.long sys_ni_syscall	/* Old sys_query_module */
+	.long sys_poll
+	.long sys_nfsservctl
+	.long sys_setresgid16	/* 170 */
+	.long sys_getresgid16
+	.long sys_prctl
+	.long sys_rt_sigreturn
+	.long sys_rt_sigaction
+	.long sys_rt_sigprocmask	/* 175 */
+	.long sys_rt_sigpending
+	.long sys_rt_sigtimedwait
+	.long sys_rt_sigqueueinfo
+	.long sys_rt_sigsuspend
+	.long sys_pread64	/* 180 */
+	.long sys_pwrite64
+	.long sys_chown16
+	.long sys_getcwd
+	.long sys_capget
+	.long sys_capset	/* 185 */
+	.long sys_sigaltstack
+	.long sys_sendfile
+	.long sys_ni_syscall	/* streams1 */
+	.long sys_ni_syscall	/* streams2 */
+	.long sys_vfork		/* 190 */
+	.long sys_getrlimit
+	.long sys_mmap2
+	.long sys_truncate64
+	.long sys_ftruncate64
+	.long sys_stat64	/* 195 */
+	.long sys_lstat64
+	.long sys_fstat64
+	.long sys_lchown
+	.long sys_getuid
+	.long sys_getgid	/* 200 */
+	.long sys_geteuid
+	.long sys_getegid
+	.long sys_setreuid
+	.long sys_setregid
+	.long sys_getgroups	/* 205 */
+	.long sys_setgroups
+	.long sys_fchown
+	.long sys_setresuid
+	.long sys_getresuid
+	.long sys_setresgid	/* 210 */
+	.long sys_getresgid
+	.long sys_chown
+	.long sys_setuid
+	.long sys_setgid
+	.long sys_setfsuid	/* 215 */
+	.long sys_setfsgid
+	.long sys_pivot_root
+	.long sys_mincore
+	.long sys_madvise
+	.long sys_getdents64	/* 220 */
+	.long sys_fcntl64
+	.long sys_ni_syscall	/* reserved for TUX */
+	.long sys_ni_syscall
+	.long sys_gettid
+	.long sys_readahead	/* 225 */
+	.long sys_setxattr
+	.long sys_lsetxattr
+	.long sys_fsetxattr
+	.long sys_getxattr
+	.long sys_lgetxattr	/* 230 */
+	.long sys_fgetxattr
+	.long sys_listxattr
+	.long sys_llistxattr
+	.long sys_flistxattr
+	.long sys_removexattr	/* 235 */
+	.long sys_lremovexattr
+	.long sys_fremovexattr
+	.long sys_tkill
+	.long sys_sendfile64
+	.long sys_futex		/* 240 */
+	.long sys_sched_setaffinity
+	.long sys_sched_getaffinity
+	.long sys_ni_syscall	/* sys_set_thread_area */
+	.long sys_ni_syscall	/* sys_get_thread_area */
+	.long sys_io_setup	/* 245 */
+	.long sys_io_destroy
+	.long sys_io_getevents
+	.long sys_io_submit
+	.long sys_io_cancel
+	.long sys_fadvise64	/* 250 */
+	.long sys_ni_syscall
+	.long sys_exit_group
+	.long sys_lookup_dcookie
+	.long sys_epoll_create
+	.long sys_epoll_ctl	/* 255 */
+	.long sys_epoll_wait
+	.long sys_remap_file_pages
+ 	.long sys_set_tid_address
+ 	.long sys_timer_create
+ 	.long sys_timer_settime		/* 260 */
+ 	.long sys_timer_gettime
+ 	.long sys_timer_getoverrun
+ 	.long sys_timer_delete
+ 	.long sys_clock_settime
+ 	.long sys_clock_gettime		/* 265 */
+ 	.long sys_clock_getres
+ 	.long sys_clock_nanosleep
+	.long sys_statfs64
+	.long sys_fstatfs64	
+	.long sys_tgkill	/* 270 */
+	.long sys_utimes
+ 	.long sys_fadvise64_64
+	.long sys_ni_syscall	/* sys_vserver */
+	.long sys_ni_syscall	/* sys_mbind */
+	.long sys_ni_syscall	/* 275 sys_get_mempolicy */
+	.long sys_ni_syscall	/* sys_set_mempolicy */
+	.long sys_mq_open
+	.long sys_mq_unlink
+	.long sys_mq_timedsend
+	.long sys_mq_timedreceive	/* 280 */
+	.long sys_mq_notify
+	.long sys_mq_getsetattr
+	.long sys_ni_syscall		/* reserved for kexec */
+	.long sys_waitid
+
+        /*
+         * NOTE!! This doesn't have to be exact - we just have
+         * to make sure we have _enough_ of the "sys_ni_syscall"
+         * entries. Don't panic if you notice that this hasn't
+         * been shrunk every time we add a new system call.
+         */
+
+	.rept NR_syscalls-(.-sys_call_table)/4
+		.long sys_ni_syscall
+	.endr
+