Linux-2.6.12-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, 720 insertions, 0 deletions

diff --git a/arch/frv/kernel/break.S b/arch/frv/kernel/break.S
new file mode 100644
index 0000000..33233dc
--- /dev/null
+++ b/arch/frv/kernel/break.S
@@ -0,0 +1,720 @@
+/* break.S: Break interrupt handling (kept separate from entry.S)
+ *
+ * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/sys.h>
+#include <linux/config.h>
+#include <linux/linkage.h>
+#include <asm/setup.h>
+#include <asm/segment.h>
+#include <asm/ptrace.h>
+#include <asm/spr-regs.h>
+
+#include <asm/errno.h>
+
+#
+# the break handler has its own stack
+#
+	.section	.bss.stack
+	.globl		__break_user_context
+	.balign		8192
+__break_stack:
+	.space		(8192 - (USER_CONTEXT_SIZE + REG__DEBUG_XTRA)) & ~7
+__break_stack_tos:
+	.space		REG__DEBUG_XTRA
+__break_user_context:
+	.space		USER_CONTEXT_SIZE
+
+#
+# miscellaneous variables
+#
+	.section	.bss
+#ifdef CONFIG_MMU
+	.globl		__break_tlb_miss_real_return_info
+__break_tlb_miss_real_return_info:
+	.balign		8
+	.space		2*4			/* saved PCSR, PSR for TLB-miss handler fixup */
+#endif
+
+__break_trace_through_exceptions:
+	.space		4
+
+#define CS2_ECS1	0xe1200000
+#define CS2_USERLED	0x4
+
+.macro LEDS val,reg
+#	sethi.p		%hi(CS2_ECS1+CS2_USERLED),gr30
+#	setlo		%lo(CS2_ECS1+CS2_USERLED),gr30
+#	setlos		#~\val,\reg
+#	st		\reg,@(gr30,gr0)
+#	setlos		#0x5555,\reg
+#	sethi.p		%hi(0xffc00100),gr30
+#	setlo		%lo(0xffc00100),gr30
+#	sth		\reg,@(gr30,gr0)
+#	membar
+.endm
+
+###############################################################################
+#
+# entry point for Break Exceptions/Interrupts
+#
+###############################################################################
+	.text
+	.balign		4
+	.globl		__entry_break
+__entry_break:
+#ifdef CONFIG_MMU
+	movgs		gr31,scr3
+#endif
+	LEDS		0x1001,gr31
+
+	sethi.p		%hi(__break_user_context),gr31
+	setlo		%lo(__break_user_context),gr31
+
+	stdi		gr2,@(gr31,#REG_GR(2))
+	movsg		ccr,gr3
+	sti		gr3,@(gr31,#REG_CCR)
+
+	# catch the return from a TLB-miss handler that had single-step disabled
+	# traps will be enabled, so we have to do this now
+#ifdef CONFIG_MMU
+	movsg		bpcsr,gr3
+	sethi.p		%hi(__break_tlb_miss_return_breaks_here),gr2
+	setlo		%lo(__break_tlb_miss_return_breaks_here),gr2
+	subcc		gr2,gr3,gr0,icc0
+	beq		icc0,#2,__break_return_singlestep_tlbmiss
+#endif
+
+	# determine whether we have stepped through into an exception
+	# - we need to take special action to suspend h/w single stepping if we've done
+	#   that, so that the gdbstub doesn't get bogged down endlessly stepping through
+	#   external interrupt handling
+	movsg		bpsr,gr3
+	andicc		gr3,#BPSR_BET,gr0,icc0
+	bne		icc0,#2,__break_maybe_userspace	/* jump if PSR.ET was 1 */
+
+	LEDS		0x1003,gr2
+
+	movsg		brr,gr3
+	andicc		gr3,#BRR_ST,gr0,icc0
+	andicc.p	gr3,#BRR_SB,gr0,icc1
+	bne		icc0,#2,__break_step		/* jump if single-step caused break */
+	beq		icc1,#2,__break_continue	/* jump if BREAK didn't cause break */
+
+	LEDS		0x1007,gr2
+
+	# handle special breaks
+	movsg		bpcsr,gr3
+
+	sethi.p		%hi(__entry_return_singlestep_breaks_here),gr2
+	setlo		%lo(__entry_return_singlestep_breaks_here),gr2
+	subcc		gr2,gr3,gr0,icc0
+	beq		icc0,#2,__break_return_singlestep
+
+	bra		__break_continue
+
+
+###############################################################################
+#
+# handle BREAK instruction in kernel-mode exception epilogue
+#
+###############################################################################
+__break_return_singlestep:
+	LEDS		0x100f,gr2
+
+	# special break insn requests single-stepping to be turned back on
+	#		HERE		RETT
+	# PSR.ET	0		0
+	# PSR.PS	old PSR.S	?
+	# PSR.S		1		1
+	# BPSR.ET	0		1 (can't have caused orig excep otherwise)
+	# BPSR.BS	1		old PSR.S
+	movsg		dcr,gr2
+	sethi.p		%hi(DCR_SE),gr3
+	setlo		%lo(DCR_SE),gr3
+	or		gr2,gr3,gr2
+	movgs		gr2,dcr
+
+	movsg		psr,gr2
+	andi		gr2,#PSR_PS,gr2
+	slli		gr2,#11,gr2			/* PSR.PS -> BPSR.BS */
+	ori		gr2,#BPSR_BET,gr2		/* 1 -> BPSR.BET */
+	movgs		gr2,bpsr
+
+	# return to the invoker of the original kernel exception
+	movsg		pcsr,gr2
+	movgs		gr2,bpcsr
+
+	LEDS		0x101f,gr2
+
+	ldi		@(gr31,#REG_CCR),gr3
+	movgs		gr3,ccr
+	lddi.p		@(gr31,#REG_GR(2)),gr2
+	xor		gr31,gr31,gr31
+	movgs		gr0,brr
+#ifdef CONFIG_MMU
+	movsg		scr3,gr31
+#endif
+	rett		#1
+
+###############################################################################
+#
+# handle BREAK instruction in TLB-miss handler return path
+#
+###############################################################################
+#ifdef CONFIG_MMU
+__break_return_singlestep_tlbmiss:
+	LEDS		0x1100,gr2
+
+	sethi.p		%hi(__break_tlb_miss_real_return_info),gr3
+	setlo		%lo(__break_tlb_miss_real_return_info),gr3
+	lddi		@(gr3,#0),gr2
+	movgs		gr2,pcsr
+	movgs		gr3,psr
+
+	bra		__break_return_singlestep
+#endif
+
+
+###############################################################################
+#
+# handle single stepping into an exception prologue from kernel mode
+# - we try and catch it whilst it is still in the main vector table
+# - if we catch it there, we have to jump to the fixup handler
+#   - there is a fixup table that has a pointer for every 16b slot in the trap
+#     table
+#
+###############################################################################
+__break_step:
+	LEDS		0x2003,gr2
+
+	# external interrupts seem to escape from the trap table before single
+	# step catches up with them
+	movsg		bpcsr,gr2
+	sethi.p		%hi(__entry_kernel_external_interrupt),gr3
+	setlo		%lo(__entry_kernel_external_interrupt),gr3
+	subcc		gr2,gr3,gr0,icc0
+	beq		icc0,#2,__break_step_kernel_external_interrupt
+	sethi.p		%hi(__entry_uspace_external_interrupt),gr3
+	setlo		%lo(__entry_uspace_external_interrupt),gr3
+	subcc		gr2,gr3,gr0,icc0
+	beq		icc0,#2,__break_step_uspace_external_interrupt
+
+	LEDS		0x2007,gr2
+
+	# the two main vector tables are adjacent on one 8Kb slab
+	movsg		bpcsr,gr2
+	setlos		#0xffffe000,gr3
+	and		gr2,gr3,gr2
+	sethi.p		%hi(__trap_tables),gr3
+	setlo		%lo(__trap_tables),gr3
+	subcc		gr2,gr3,gr0,icc0
+	bne		icc0,#2,__break_continue
+
+	LEDS		0x200f,gr2
+
+	# skip workaround if so requested by GDB
+	sethi.p		%hi(__break_trace_through_exceptions),gr3
+	setlo		%lo(__break_trace_through_exceptions),gr3
+	ld		@(gr3,gr0),gr3
+	subcc		gr3,gr0,gr0,icc0
+	bne		icc0,#0,__break_continue
+
+	LEDS		0x201f,gr2
+
+	# access the fixup table - there's a 1:1 mapping between the slots in the trap tables and
+	# the slots in the trap fixup tables allowing us to simply divide the offset into the
+	# former by 4 to access the latter
+	sethi.p		%hi(__trap_tables),gr3
+	setlo		%lo(__trap_tables),gr3
+	movsg		bpcsr,gr2
+	sub		gr2,gr3,gr2
+	srli.p		gr2,#2,gr2
+
+	sethi		%hi(__trap_fixup_tables),gr3
+	setlo.p		%lo(__trap_fixup_tables),gr3
+	andi		gr2,#~3,gr2
+	ld		@(gr2,gr3),gr2
+	jmpil		@(gr2,#0)
+
+# step through an internal exception from kernel mode
+	.globl		__break_step_kernel_softprog_interrupt
+__break_step_kernel_softprog_interrupt:
+	sethi.p		%hi(__entry_kernel_softprog_interrupt_reentry),gr3
+	setlo		%lo(__entry_kernel_softprog_interrupt_reentry),gr3
+	bra		__break_return_as_kernel_prologue
+
+# step through an external interrupt from kernel mode
+	.globl		__break_step_kernel_external_interrupt
+__break_step_kernel_external_interrupt:
+	sethi.p		%hi(__entry_kernel_external_interrupt_reentry),gr3
+	setlo		%lo(__entry_kernel_external_interrupt_reentry),gr3
+
+__break_return_as_kernel_prologue:
+	LEDS		0x203f,gr2
+
+	movgs		gr3,bpcsr
+
+	# do the bit we had to skip
+#ifdef CONFIG_MMU
+	movsg		ear0,gr2		/* EAR0 can get clobbered by gdb-stub (ICI/ICEI) */
+	movgs		gr2,scr2
+#endif
+
+	or.p		sp,gr0,gr2		/* set up the stack pointer */
+	subi		sp,#REG__END,sp
+	sti.p		gr2,@(sp,#REG_SP)
+
+	setlos		#REG__STATUS_STEP,gr2
+	sti		gr2,@(sp,#REG__STATUS)		/* record single step status */
+
+	# cancel single-stepping mode
+	movsg		dcr,gr2
+	sethi.p		%hi(~DCR_SE),gr3
+	setlo		%lo(~DCR_SE),gr3
+	and		gr2,gr3,gr2
+	movgs		gr2,dcr
+
+	LEDS		0x207f,gr2
+
+	ldi		@(gr31,#REG_CCR),gr3
+	movgs		gr3,ccr
+	lddi.p		@(gr31,#REG_GR(2)),gr2
+	xor		gr31,gr31,gr31
+	movgs		gr0,brr
+#ifdef CONFIG_MMU
+	movsg		scr3,gr31
+#endif
+	rett		#1
+
+# step through an internal exception from uspace mode
+	.globl		__break_step_uspace_softprog_interrupt
+__break_step_uspace_softprog_interrupt:
+	sethi.p		%hi(__entry_uspace_softprog_interrupt_reentry),gr3
+	setlo		%lo(__entry_uspace_softprog_interrupt_reentry),gr3
+	bra		__break_return_as_uspace_prologue
+
+# step through an external interrupt from kernel mode
+	.globl		__break_step_uspace_external_interrupt
+__break_step_uspace_external_interrupt:
+	sethi.p		%hi(__entry_uspace_external_interrupt_reentry),gr3
+	setlo		%lo(__entry_uspace_external_interrupt_reentry),gr3
+
+__break_return_as_uspace_prologue:
+	LEDS		0x20ff,gr2
+
+	movgs		gr3,bpcsr
+
+	# do the bit we had to skip
+	sethi.p		%hi(__kernel_frame0_ptr),gr28
+	setlo		%lo(__kernel_frame0_ptr),gr28
+	ldi.p		@(gr28,#0),gr28
+
+	setlos		#REG__STATUS_STEP,gr2
+	sti		gr2,@(gr28,#REG__STATUS)	/* record single step status */
+
+	# cancel single-stepping mode
+	movsg		dcr,gr2
+	sethi.p		%hi(~DCR_SE),gr3
+	setlo		%lo(~DCR_SE),gr3
+	and		gr2,gr3,gr2
+	movgs		gr2,dcr
+
+	LEDS		0x20fe,gr2
+
+	ldi		@(gr31,#REG_CCR),gr3
+	movgs		gr3,ccr
+	lddi.p		@(gr31,#REG_GR(2)),gr2
+	xor		gr31,gr31,gr31
+	movgs		gr0,brr
+#ifdef CONFIG_MMU
+	movsg		scr3,gr31
+#endif
+	rett		#1
+
+#ifdef CONFIG_MMU
+# step through an ITLB-miss handler from user mode
+	.globl		__break_user_insn_tlb_miss
+__break_user_insn_tlb_miss:
+	# we'll want to try the trap stub again
+	sethi.p		%hi(__trap_user_insn_tlb_miss),gr2
+	setlo		%lo(__trap_user_insn_tlb_miss),gr2
+	movgs		gr2,bpcsr
+
+__break_tlb_miss_common:
+	LEDS		0x2101,gr2
+
+	# cancel single-stepping mode
+	movsg		dcr,gr2
+	sethi.p		%hi(~DCR_SE),gr3
+	setlo		%lo(~DCR_SE),gr3
+	and		gr2,gr3,gr2
+	movgs		gr2,dcr
+
+	# we'll swap the real return address for one with a BREAK insn so that we can re-enable
+	# single stepping on return
+	movsg		pcsr,gr2
+	sethi.p		%hi(__break_tlb_miss_real_return_info),gr3
+	setlo		%lo(__break_tlb_miss_real_return_info),gr3
+	sti		gr2,@(gr3,#0)
+
+	sethi.p		%hi(__break_tlb_miss_return_break),gr2
+	setlo		%lo(__break_tlb_miss_return_break),gr2
+	movgs		gr2,pcsr
+
+	# we also have to fudge PSR because the return BREAK is in kernel space and we want
+	# to get a BREAK fault not an access violation should the return be to userspace
+	movsg		psr,gr2
+	sti.p		gr2,@(gr3,#4)
+	ori		gr2,#PSR_PS,gr2
+	movgs		gr2,psr
+
+	LEDS		0x2102,gr2
+
+	ldi		@(gr31,#REG_CCR),gr3
+	movgs		gr3,ccr
+	lddi		@(gr31,#REG_GR(2)),gr2
+	movsg		scr3,gr31
+	movgs		gr0,brr
+	rett		#1
+
+# step through a DTLB-miss handler from user mode
+	.globl		__break_user_data_tlb_miss
+__break_user_data_tlb_miss:
+	# we'll want to try the trap stub again
+	sethi.p		%hi(__trap_user_data_tlb_miss),gr2
+	setlo		%lo(__trap_user_data_tlb_miss),gr2
+	movgs		gr2,bpcsr
+	bra		__break_tlb_miss_common
+
+# step through an ITLB-miss handler from kernel mode
+	.globl		__break_kernel_insn_tlb_miss
+__break_kernel_insn_tlb_miss:
+	# we'll want to try the trap stub again
+	sethi.p		%hi(__trap_kernel_insn_tlb_miss),gr2
+	setlo		%lo(__trap_kernel_insn_tlb_miss),gr2
+	movgs		gr2,bpcsr
+	bra		__break_tlb_miss_common
+
+# step through a DTLB-miss handler from kernel mode
+	.globl		__break_kernel_data_tlb_miss
+__break_kernel_data_tlb_miss:
+	# we'll want to try the trap stub again
+	sethi.p		%hi(__trap_kernel_data_tlb_miss),gr2
+	setlo		%lo(__trap_kernel_data_tlb_miss),gr2
+	movgs		gr2,bpcsr
+	bra		__break_tlb_miss_common
+#endif
+
+###############################################################################
+#
+# handle debug events originating with userspace
+#
+###############################################################################
+__break_maybe_userspace:
+	LEDS		0x3003,gr2
+
+	setlos		#BPSR_BS,gr2
+	andcc		gr3,gr2,gr0,icc0
+	bne		icc0,#0,__break_continue	/* skip if PSR.S was 1 */
+
+	movsg		brr,gr2
+	andicc		gr2,#BRR_ST|BRR_SB,gr0,icc0
+	beq		icc0,#0,__break_continue	/* jump if not BREAK or single-step */
+
+	LEDS		0x3007,gr2
+
+	# do the first part of the exception prologue here
+	sethi.p		%hi(__kernel_frame0_ptr),gr28
+	setlo		%lo(__kernel_frame0_ptr),gr28
+	ldi		@(gr28,#0),gr28
+	andi		gr28,#~7,gr28
+
+	# set up the kernel stack pointer
+	sti		sp  ,@(gr28,#REG_SP)
+	ori		gr28,0,sp
+	sti		gr0 ,@(gr28,#REG_GR(28))
+
+	stdi		gr20,@(gr28,#REG_GR(20))
+	stdi		gr22,@(gr28,#REG_GR(22))
+
+	movsg		tbr,gr20
+	movsg		bpcsr,gr21
+	movsg		psr,gr22
+
+	# determine the exception type and cancel single-stepping mode
+	or		gr0,gr0,gr23
+
+	movsg		dcr,gr2
+	sethi.p		%hi(DCR_SE),gr3
+	setlo		%lo(DCR_SE),gr3
+	andcc		gr2,gr3,gr0,icc0
+	beq		icc0,#0,__break_no_user_sstep	/* must have been a BREAK insn */
+
+	not		gr3,gr3
+	and		gr2,gr3,gr2
+	movgs		gr2,dcr
+	ori		gr23,#REG__STATUS_STEP,gr23
+
+__break_no_user_sstep:
+	LEDS		0x300f,gr2
+
+	movsg		brr,gr2
+	andi		gr2,#BRR_ST|BRR_SB,gr2
+	slli		gr2,#1,gr2
+	or		gr23,gr2,gr23
+	sti.p		gr23,@(gr28,#REG__STATUS)	/* record single step status */
+
+	# adjust the value acquired from TBR - this indicates the exception
+	setlos		#~TBR_TT,gr2
+	and.p		gr20,gr2,gr20
+	setlos		#TBR_TT_BREAK,gr2
+	or.p		gr20,gr2,gr20
+
+	# fudge PSR.PS and BPSR.BS to return to kernel mode through the trap
+	# table as trap 126
+	andi		gr22,#~PSR_PS,gr22		/* PSR.PS should be 0 */
+	movgs		gr22,psr
+
+	setlos		#BPSR_BS,gr2			/* BPSR.BS should be 1 and BPSR.BET 0 */
+	movgs		gr2,bpsr
+
+	# return through remainder of the exception prologue
+	# - need to load gr23 with return handler address
+	sethi.p		%hi(__entry_return_from_user_exception),gr23
+	setlo		%lo(__entry_return_from_user_exception),gr23
+	sethi.p		%hi(__entry_common),gr3
+	setlo		%lo(__entry_common),gr3
+	movgs		gr3,bpcsr
+
+	LEDS		0x301f,gr2
+
+	ldi		@(gr31,#REG_CCR),gr3
+	movgs		gr3,ccr
+	lddi.p		@(gr31,#REG_GR(2)),gr2
+	xor		gr31,gr31,gr31
+	movgs		gr0,brr
+#ifdef CONFIG_MMU
+	movsg		scr3,gr31
+#endif
+	rett		#1
+
+###############################################################################
+#
+# resume normal debug-mode entry
+#
+###############################################################################
+__break_continue:
+	LEDS		0x4003,gr2
+
+	# set up the kernel stack pointer
+	sti		sp,@(gr31,#REG_SP)
+
+	sethi.p		%hi(__break_stack_tos),sp
+	setlo		%lo(__break_stack_tos),sp
+
+	# finish building the exception frame
+	stdi		gr4 ,@(gr31,#REG_GR(4))
+	stdi		gr6 ,@(gr31,#REG_GR(6))
+	stdi		gr8 ,@(gr31,#REG_GR(8))
+	stdi		gr10,@(gr31,#REG_GR(10))
+	stdi		gr12,@(gr31,#REG_GR(12))
+	stdi		gr14,@(gr31,#REG_GR(14))
+	stdi		gr16,@(gr31,#REG_GR(16))
+	stdi		gr18,@(gr31,#REG_GR(18))
+	stdi		gr20,@(gr31,#REG_GR(20))
+	stdi		gr22,@(gr31,#REG_GR(22))
+	stdi		gr24,@(gr31,#REG_GR(24))
+	stdi		gr26,@(gr31,#REG_GR(26))
+	sti		gr0 ,@(gr31,#REG_GR(28))	/* NULL frame pointer */
+	sti		gr29,@(gr31,#REG_GR(29))
+	sti		gr30,@(gr31,#REG_GR(30))
+	sti		gr8 ,@(gr31,#REG_ORIG_GR8)
+
+#ifdef CONFIG_MMU
+	movsg		scr3,gr19
+	sti		gr19,@(gr31,#REG_GR(31))
+#endif
+
+	movsg		bpsr ,gr19
+	movsg		tbr  ,gr20
+	movsg		bpcsr,gr21
+	movsg		psr  ,gr22
+	movsg		isr  ,gr23
+	movsg		cccr ,gr25
+	movsg		lr   ,gr26
+	movsg		lcr  ,gr27
+
+	andi.p		gr22,#~(PSR_S|PSR_ET),gr5	/* rebuild PSR */
+	andi		gr19,#PSR_ET,gr4
+	or.p		gr4,gr5,gr5
+	srli		gr19,#10,gr4
+	andi		gr4,#PSR_S,gr4
+	or.p		gr4,gr5,gr5
+
+	setlos		#-1,gr6
+	sti		gr20,@(gr31,#REG_TBR)
+	sti		gr21,@(gr31,#REG_PC)
+	sti		gr5 ,@(gr31,#REG_PSR)
+	sti		gr23,@(gr31,#REG_ISR)
+	sti		gr25,@(gr31,#REG_CCCR)
+	stdi		gr26,@(gr31,#REG_LR)
+	sti		gr6 ,@(gr31,#REG_SYSCALLNO)
+
+	# store CPU-specific regs
+	movsg		iacc0h,gr4
+	movsg		iacc0l,gr5
+	stdi		gr4,@(gr31,#REG_IACC0)
+
+	movsg		gner0,gr4
+	movsg		gner1,gr5
+	stdi		gr4,@(gr31,#REG_GNER0)
+
+	# build the debug register frame
+	movsg		brr,gr4
+	movgs		gr0,brr
+	movsg		nmar,gr5
+	movsg		dcr,gr6
+
+	stdi		gr4 ,@(gr31,#REG_BRR)
+	sti		gr19,@(gr31,#REG_BPSR)
+	sti.p		gr6 ,@(gr31,#REG_DCR)
+
+	# trap exceptions during break handling and disable h/w breakpoints/watchpoints
+	sethi		%hi(DCR_EBE),gr5
+	setlo.p		%lo(DCR_EBE),gr5
+	sethi		%hi(__entry_breaktrap_table),gr4
+	setlo		%lo(__entry_breaktrap_table),gr4
+	movgs		gr5,dcr
+	movgs		gr4,tbr
+
+	# set up kernel global registers
+	sethi.p		%hi(__kernel_current_task),gr5
+	setlo		%lo(__kernel_current_task),gr5
+	ld		@(gr5,gr0),gr29
+	ldi.p		@(gr29,#4),gr15		; __current_thread_info = current->thread_info
+
+	sethi		%hi(_gp),gr16
+	setlo.p		%lo(_gp),gr16
+
+	# make sure we (the kernel) get div-zero and misalignment exceptions
+	setlos		#ISR_EDE|ISR_DTT_DIVBYZERO|ISR_EMAM_EXCEPTION,gr5
+	movgs		gr5,isr
+
+	# enter the GDB stub
+	LEDS		0x4007,gr2
+
+	or.p		gr0,gr0,fp
+	call		debug_stub
+
+	LEDS		0x403f,gr2
+
+	# return from break
+	lddi		@(gr31,#REG_IACC0),gr4
+	movgs		gr4,iacc0h
+	movgs		gr5,iacc0l
+
+	lddi		@(gr31,#REG_GNER0),gr4
+	movgs		gr4,gner0
+	movgs		gr5,gner1
+
+	lddi		@(gr31,#REG_LR)  ,gr26
+	lddi		@(gr31,#REG_CCR) ,gr24
+	lddi		@(gr31,#REG_PSR) ,gr22
+	ldi		@(gr31,#REG_PC)  ,gr21
+	ldi		@(gr31,#REG_TBR) ,gr20
+	ldi.p		@(gr31,#REG_DCR) ,gr6
+
+	andi		gr22,#PSR_S,gr19		/* rebuild BPSR */
+	andi.p		gr22,#PSR_ET,gr5
+	slli		gr19,#10,gr19
+	or		gr5,gr19,gr19
+
+	movgs		gr6 ,dcr
+	movgs		gr19,bpsr
+	movgs		gr20,tbr
+	movgs		gr21,bpcsr
+	movgs		gr23,isr
+	movgs		gr24,ccr
+	movgs		gr25,cccr
+	movgs		gr26,lr
+	movgs		gr27,lcr
+
+	LEDS		0x407f,gr2
+
+#ifdef CONFIG_MMU
+	ldi		@(gr31,#REG_GR(31)),gr2
+	movgs		gr2,scr3
+#endif
+
+	ldi		@(gr31,#REG_GR(30)),gr30
+	ldi		@(gr31,#REG_GR(29)),gr29
+	lddi		@(gr31,#REG_GR(26)),gr26
+	lddi		@(gr31,#REG_GR(24)),gr24
+	lddi		@(gr31,#REG_GR(22)),gr22
+	lddi		@(gr31,#REG_GR(20)),gr20
+	lddi		@(gr31,#REG_GR(18)),gr18
+	lddi		@(gr31,#REG_GR(16)),gr16
+	lddi		@(gr31,#REG_GR(14)),gr14
+	lddi		@(gr31,#REG_GR(12)),gr12
+	lddi		@(gr31,#REG_GR(10)),gr10
+	lddi		@(gr31,#REG_GR(8)) ,gr8
+	lddi		@(gr31,#REG_GR(6)) ,gr6
+	lddi		@(gr31,#REG_GR(4)) ,gr4
+	lddi		@(gr31,#REG_GR(2)) ,gr2
+	ldi.p		@(gr31,#REG_SP)    ,sp
+
+	xor		gr31,gr31,gr31
+	movgs		gr0,brr
+#ifdef CONFIG_MMU
+	movsg		scr3,gr31
+#endif
+	rett		#1
+
+###################################################################################################
+#
+# GDB stub "system calls"
+#
+###################################################################################################
+
+#ifdef CONFIG_GDBSTUB
+	# void gdbstub_console_write(struct console *con, const char *p, unsigned n)
+	.globl		gdbstub_console_write
+gdbstub_console_write:
+	break
+	bralr
+#endif
+
+	# GDB stub BUG() trap
+	# GR8 is the proposed signal number
+	.globl		__debug_bug_trap
+__debug_bug_trap:
+	break
+	bralr
+
+	# transfer kernel exeception to GDB for handling
+	.globl		__break_hijack_kernel_event
+__break_hijack_kernel_event:
+	break
+	.globl		__break_hijack_kernel_event_breaks_here
+__break_hijack_kernel_event_breaks_here:
+	nop
+
+#ifdef CONFIG_MMU
+	# handle a return from TLB-miss that requires single-step reactivation
+	.globl		__break_tlb_miss_return_break
+__break_tlb_miss_return_break:
+	break
+__break_tlb_miss_return_breaks_here:
+	nop
+#endif
+
+	# guard the first .text label in the next file from confusion
+	nop