Add kexec jump support to the SuperH architecture. Similar to the x86 implementation, with the following exceptions: - Instead of separating the assembly code flow into two parts for regular kexec and kexec jump we use a single code path. In the assembly snippet regular kexec is just kexec jump that never comes back. - Instead of using a swap page when moving data between pages the page copy assembly routine has been modified to exchange the data between the pages using registers. - We walk the page list twice in machine_kexec() to do and undo physical to virtual address conversion. Signed-off-by: Magnus Damm <damm@igel.co.jp> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
		
			
				
	
	
		
			232 lines
		
	
	
	
		
			4.1 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			232 lines
		
	
	
	
		
			4.1 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
/*
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 * relocate_kernel.S - put the kernel image in place to boot
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 * 2005.9.17 kogiidena@eggplant.ddo.jp
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 *
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 * LANDISK/sh4 is supported. Maybe, SH archtecture works well.
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 *
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 * 2009-03-18 Magnus Damm - Added Kexec Jump support
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 *
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 * This source code is licensed under the GNU General Public License,
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 * Version 2.  See the file COPYING for more details.
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 */
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#include <linux/linkage.h>
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#include <asm/addrspace.h>
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#include <asm/page.h>
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		.globl relocate_new_kernel
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relocate_new_kernel:
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	/* r4 = indirection_page   */
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	/* r5 = reboot_code_buffer */
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	/* r6 = start_address      */
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	mov.l	10f, r0		/* PAGE_SIZE */
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	add	r5, r0		/* setup new stack at end of control page */
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	/* save r15->r8 to new stack */
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	mov.l	r15, @-r0
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	mov	r0, r15
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	mov.l	r14, @-r15
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	mov.l	r13, @-r15
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	mov.l	r12, @-r15
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	mov.l	r11, @-r15
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	mov.l	r10, @-r15
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	mov.l	r9, @-r15
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	mov.l	r8, @-r15
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	/* save other random registers */
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	sts.l	macl, @-r15
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	sts.l	mach, @-r15
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	stc.l	gbr, @-r15
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	stc.l	ssr, @-r15
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	stc.l	sr, @-r15
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	sts.l	pr, @-r15
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	stc.l	spc, @-r15
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	/* switch to bank1 and save r7->r0 */
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	mov.l	12f, r9
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	stc	sr, r8
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	or	r9, r8
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	ldc	r8, sr
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	mov.l	r7, @-r15
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	mov.l	r6, @-r15
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	mov.l	r5, @-r15
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	mov.l	r4, @-r15
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	mov.l	r3, @-r15
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	mov.l	r2, @-r15
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	mov.l	r1, @-r15
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	mov.l	r0, @-r15
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	/* switch to bank0 and save r7->r0 */
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	mov.l	12f, r9
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	not	r9, r9
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	stc	sr, r8
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	and	r9, r8
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	ldc	r8, sr
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	mov.l	r7, @-r15
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	mov.l	r6, @-r15
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	mov.l	r5, @-r15
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	mov.l	r4, @-r15
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	mov.l	r3, @-r15
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	mov.l	r2, @-r15
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	mov.l	r1, @-r15
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	mov.l	r0, @-r15
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	mov.l	r4, @-r15	/* save indirection page again */
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	bsr	swap_pages	/* swap pages before jumping to new kernel */
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	 nop
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	mova	11f, r0
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	mov.l	r15, @r0	/* save pointer to stack */
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	jsr	@r6		/* hand over control to new kernel */
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	 nop
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	mov.l	11f, r15	/* get pointer to stack */
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	mov.l	@r15+, r4	/* restore r4 to get indirection page */
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	bsr	swap_pages	/* swap pages back to previous state */
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	 nop
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	/* make sure bank0 is active and restore r0->r7 */
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	mov.l	12f, r9
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	not	r9, r9
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	stc	sr, r8
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	and	r9, r8
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	ldc	r8, sr
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	mov.l	@r15+, r0
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	mov.l	@r15+, r1
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	mov.l	@r15+, r2
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	mov.l	@r15+, r3
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	mov.l	@r15+, r4
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	mov.l	@r15+, r5
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	mov.l	@r15+, r6
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	mov.l	@r15+, r7
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	/* switch to bank1 and restore r0->r7 */
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	mov.l	12f, r9
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	stc	sr, r8
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	or	r9, r8
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	ldc	r8, sr
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	mov.l	@r15+, r0
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	mov.l	@r15+, r1
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	mov.l	@r15+, r2
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	mov.l	@r15+, r3
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	mov.l	@r15+, r4
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	mov.l	@r15+, r5
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	mov.l	@r15+, r6
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	mov.l	@r15+, r7
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	/* switch back to bank0 */
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	mov.l	12f, r9
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	not	r9, r9
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	stc	sr, r8
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	and	r9, r8
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	ldc	r8, sr
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	/* restore other random registers */
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	ldc.l	@r15+, spc
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	lds.l	@r15+, pr
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	ldc.l	@r15+, sr
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	ldc.l	@r15+, ssr
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	ldc.l	@r15+, gbr
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	lds.l	@r15+, mach
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	lds.l	@r15+, macl
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	/* restore r8->r15 */
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	mov.l	@r15+, r8
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	mov.l	@r15+, r9
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	mov.l	@r15+, r10
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	mov.l	@r15+, r11
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	mov.l	@r15+, r12
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	mov.l	@r15+, r13
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	mov.l	@r15+, r14
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	mov.l	@r15+, r15
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	rts
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	 nop
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swap_pages:
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	bra	1f
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	 mov	r4,r0	  /* cmd = indirection_page */
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0:
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	mov.l	@r4+,r0	  /* cmd = *ind++ */
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1:	/* addr = cmd & 0xfffffff0 */
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	mov	r0,r2
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	mov	#-16,r1
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	and	r1,r2
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	/* if(cmd & IND_DESTINATION) dst = addr  */
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	tst	#1,r0
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	bt	2f
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	bra	0b
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	 mov	r2,r5
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2:	/* else if(cmd & IND_INDIRECTION) ind = addr  */
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	tst	#2,r0
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	bt	3f
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	bra	0b
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	 mov	r2,r4
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3:	/* else if(cmd & IND_DONE) return */
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	tst	#4,r0
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	bt	4f
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	rts
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	 nop
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4:	/* else if(cmd & IND_SOURCE) memcpy(dst,addr,PAGE_SIZE) */
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	tst	#8,r0
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	bt	0b
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	mov.l	10f,r3	  /* PAGE_SIZE */
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	shlr2	r3
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	shlr2	r3
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5:
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	dt	r3
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	/* regular kexec just overwrites the destination page
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	 * with the contents of the source page.
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	 * for the kexec jump case we need to swap the contents
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	 * of the pages.
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	 * to keep it simple swap the contents for both cases.
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	 */
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	mov.l	@(0, r2), r8
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	mov.l	@(0, r5), r1
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	mov.l	r8, @(0, r5)
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	mov.l	r1, @(0, r2)
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	mov.l	@(4, r2), r8
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	mov.l	@(4, r5), r1
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	mov.l	r8, @(4, r5)
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	mov.l	r1, @(4, r2)
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	mov.l	@(8, r2), r8
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	mov.l	@(8, r5), r1
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	mov.l	r8, @(8, r5)
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	mov.l	r1, @(8, r2)
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	mov.l	@(12, r2), r8
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	mov.l	@(12, r5), r1
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	mov.l	r8, @(12, r5)
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	mov.l	r1, @(12, r2)
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	add	#16,r5
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	add	#16,r2
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	bf	5b
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	bra	0b
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	 nop
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	.align 2
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10:
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	.long	PAGE_SIZE
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11:
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	.long	0
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12:
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	.long	0x20000000 ! RB=1
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relocate_new_kernel_end:
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	.globl relocate_new_kernel_size
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relocate_new_kernel_size:
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	.long relocate_new_kernel_end - relocate_new_kernel
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