121 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			121 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
/*
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 * kexec trampoline
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 *
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 * Based on code taken from kexec-tools and kexec-lite.
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 *
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 * Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation
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 * Copyright (C) 2006, Mohan Kumar M, IBM Corporation
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 * Copyright (C) 2013, Anton Blanchard, IBM Corporation
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 *
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 * This program is free software; you can redistribute it and/or modify it under
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 * the terms of the GNU General Public License as published by the Free
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 * Software Foundation (version 2 of the License).
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 */
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#include <asm/asm-compat.h>
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	.machine ppc64
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	.balign 256
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	.globl purgatory_start
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purgatory_start:
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	b	master
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	/* ABI: possible run_at_load flag at 0x5c */
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	.org purgatory_start + 0x5c
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	.globl run_at_load
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run_at_load:
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	.long 0
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	.size run_at_load, . - run_at_load
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	/* ABI: slaves start at 60 with r3=phys */
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	.org purgatory_start + 0x60
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slave:
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	b .
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	/* ABI: end of copied region */
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	.org purgatory_start + 0x100
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	.size purgatory_start, . - purgatory_start
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/*
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 * The above 0x100 bytes at purgatory_start are replaced with the
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 * code from the kernel (or next stage) by setup_purgatory().
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 */
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master:
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	or	%r1,%r1,%r1	/* low priority to let other threads catchup */
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	isync
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	mr	%r17,%r3	/* save cpu id to r17 */
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	mr	%r15,%r4	/* save physical address in reg15 */
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	or	%r3,%r3,%r3	/* ok now to high priority, lets boot */
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	lis	%r6,0x1
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	mtctr	%r6		/* delay a bit for slaves to catch up */
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	bdnz	.		/* before we overwrite 0-100 again */
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	bl	0f		/* Work out where we're running */
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0:	mflr	%r18
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	/* load device-tree address */
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	ld	%r3, (dt_offset - 0b)(%r18)
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	mr	%r16,%r3	/* save dt address in reg16 */
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	li	%r4,20
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	LWZX_BE	%r6,%r3,%r4	/* fetch __be32 version number at byte 20 */
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	cmpwi	%cr0,%r6,2	/* v2 or later? */
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	blt	1f
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	li	%r4,28
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	STWX_BE	%r17,%r3,%r4	/* Store my cpu as __be32 at byte 28 */
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1:
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	/* load the kernel address */
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	ld	%r4,(kernel - 0b)(%r18)
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	/* load the run_at_load flag */
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	/* possibly patched by kexec */
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	ld	%r6,(run_at_load - 0b)(%r18)
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	/* and patch it into the kernel */
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	stw	%r6,(0x5c)(%r4)
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	mr	%r3,%r16	/* restore dt address */
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	li	%r5,0		/* r5 will be 0 for kernel */
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	mfmsr	%r11
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	andi.	%r10,%r11,1	/* test MSR_LE */
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	bne	.Little_endian
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	mtctr	%r4		/* prepare branch to */
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	bctr			/* start kernel */
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.Little_endian:
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	mtsrr0	%r4		/* prepare branch to */
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	clrrdi	%r11,%r11,1	/* clear MSR_LE */
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	mtsrr1	%r11
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	rfid			/* update MSR and start kernel */
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	.balign 8
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	.globl kernel
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kernel:
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	.8byte  0x0
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	.size kernel, . - kernel
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	.balign 8
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	.globl dt_offset
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dt_offset:
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	.8byte  0x0
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	.size dt_offset, . - dt_offset
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	.data
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	.balign 8
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.globl purgatory_sha256_digest
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purgatory_sha256_digest:
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	.skip	32
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	.size purgatory_sha256_digest, . - purgatory_sha256_digest
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	.balign 8
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.globl purgatory_sha_regions
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purgatory_sha_regions:
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	.skip	8 * 2 * 16
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	.size purgatory_sha_regions, . - purgatory_sha_regions
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