164 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
		
		
			
		
	
	
			164 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
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								/*
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								 * linux/arch/unicore32/lib/backtrace.S
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								 *
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								 * Code specific to PKUnity SoC and UniCore ISA
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								 *
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								 * Copyright (C) 2001-2010 GUAN Xue-tao
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								 *
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								 * This program is free software; you can redistribute it and/or modify
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								 * it under the terms of the GNU General Public License version 2 as
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								 * published by the Free Software Foundation.
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								 */
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								#include <linux/linkage.h>
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								#include <asm/assembler.h>
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										.text
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								@ fp is 0 or stack frame
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								#define frame	v4
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								#define sv_fp	v5
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								#define sv_pc	v6
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								#define offset	v8
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								ENTRY(__backtrace)
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										mov	r0, fp
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								ENTRY(c_backtrace)
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								#if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK)
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										mov	pc, lr
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								ENDPROC(__backtrace)
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								ENDPROC(c_backtrace)
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								#else
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										stm.w	(v4 - v8, lr), [sp-]	@ Save an extra register
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														@ so we have a location...
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										mov.a	frame, r0		@ if frame pointer is zero
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										beq	no_frame		@ we have no stack frames
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								1:		stm.w	(pc), [sp-]		@ calculate offset of PC stored
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										ldw.w	r0, [sp]+, #4		@ by stmfd for this CPU
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										adr	r1, 1b
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										sub	offset, r0, r1
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								/*
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								 * Stack frame layout:
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								 *             optionally saved caller registers (r4 - r10)
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								 *             saved fp
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								 *             saved sp
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								 *             saved lr
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								 *    frame => saved pc
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								 *             optionally saved arguments (r0 - r3)
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								 * saved sp => <next word>
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								 *
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								 * Functions start with the following code sequence:
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								 *                  mov   ip, sp
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								 *                  stm.w (r0 - r3), [sp-] (optional)
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								 * corrected pc =>  stm.w sp, (..., fp, ip, lr, pc)
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								 */
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								for_each_frame:
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								1001:		ldw	sv_pc, [frame+], #0	@ get saved pc
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								1002:		ldw	sv_fp, [frame+], #-12	@ get saved fp
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										sub	sv_pc, sv_pc, offset	@ Correct PC for prefetching
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								1003:		ldw	r2, [sv_pc+], #-4	@ if stmfd sp, {args} exists,
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										ldw	r3, .Ldsi+4		@ adjust saved 'pc' back one
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										cxor.a	r3, r2 >> #14		@ instruction
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										beq	201f
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										sub	r0, sv_pc, #4		@ allow for mov
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										b	202f
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								201:
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										sub	r0, sv_pc, #8		@ allow for mov + stmia
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								202:
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										ldw	r1, [frame+], #-4	@ get saved lr
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										mov	r2, frame
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										b.l	dump_backtrace_entry
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										ldw	r1, [sv_pc+], #-4	@ if stmfd sp, {args} exists,
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										ldw	r3, .Ldsi+4
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										cxor.a	r3, r1 >> #14
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										bne	1004f
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										ldw	r0, [frame+], #-8	@ get sp
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										sub	r0, r0, #4		@ point at the last arg
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										b.l	.Ldumpstm		@ dump saved registers
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								1004:		ldw	r1, [sv_pc+], #0	@ if stmfd {, fp, ip, lr, pc}
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										ldw	r3, .Ldsi		@ instruction exists,
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										cxor.a	r3, r1 >> #14
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										bne	201f
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										sub	r0, frame, #16
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										b.l	.Ldumpstm		@ dump saved registers
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								201:
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										cxor.a	sv_fp, #0		@ zero saved fp means
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										beq	no_frame		@ no further frames
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										csub.a	sv_fp, frame		@ next frame must be
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										mov	frame, sv_fp		@ above the current frame
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										bua	for_each_frame
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								1006:		adr	r0, .Lbad
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										mov	r1, frame
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										b.l	printk
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								no_frame:	ldm.w	(v4 - v8, pc), [sp]+
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								ENDPROC(__backtrace)
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								ENDPROC(c_backtrace)
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										.pushsection __ex_table,"a"
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										.align	3
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										.long	1001b, 1006b
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										.long	1002b, 1006b
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										.long	1003b, 1006b
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										.long	1004b, 1006b
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										.popsection
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								#define instr v4
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								#define reg   v5
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								#define stack v6
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								.Ldumpstm:	stm.w	(instr, reg, stack, v7, lr), [sp-]
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										mov	stack, r0
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										mov	instr, r1
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										mov	reg, #14
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										mov	v7, #0
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								1:		mov	r3, #1
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										csub.a	reg, #8
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										bne	201f
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										sub	reg, reg, #3
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								201:
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										cand.a	instr, r3 << reg
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										beq	2f
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										add	v7, v7, #1
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										cxor.a	v7, #6
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										cmoveq	v7, #1
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										cmoveq	r1, #'\n'
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										cmovne	r1, #' '
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										ldw.w	r3, [stack]+, #-4
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										mov	r2, reg
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										csub.a	r2, #8
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										bsl	201f
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										sub	r2, r2, #3
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								201:
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										cand.a	instr, #0x40		@ if H is 1, high 16 regs
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										beq	201f
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										add	r2, r2, #0x10		@ so r2 need add 16
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								201:
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										adr	r0, .Lfp
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										b.l	printk
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								2:		sub.a	reg, reg, #1
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										bns	1b
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										cxor.a	v7, #0
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										beq	201f
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										adr	r0, .Lcr
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										b.l	printk
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								201:		ldm.w	(instr, reg, stack, v7, pc), [sp]+
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								.Lfp:		.asciz	"%cr%d:%08x"
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								.Lcr:		.asciz	"\n"
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								.Lbad:		.asciz	"Backtrace aborted due to bad frame pointer <%p>\n"
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										.align
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								.Ldsi:		.word	0x92eec000 >> 14	@ stm.w sp, (... fp, ip, lr, pc)
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										.word	0x92e10000 >> 14	@ stm.w sp, ()
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								#endif
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