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#include "mem.h"
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/*
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 * Turn off MMU, then memmove the new kernel to its correct location
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 * in physical memory.  Then jump to the start of the kernel.
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 */
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TEXT	main(SB),$0
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	MOVL	p1+0(FP), DI		/* destination */
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	MOVL	DI, AX			/* entry point */
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	MOVL	p2+4(FP), SI		/* source */
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	MOVL	n+8(FP), CX		/* byte count */
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/*
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 * disable paging
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 */
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	MOVL	CR0, DX
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	ANDL	$~0x80000000, DX		/* ~(PG) */
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	MOVL	DX, CR0
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	MOVL	$0, DX
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	MOVL	DX, CR3
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/*
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 * the source and destination may overlap.
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 * determine whether to copy forward or backwards
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 */
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	CMPL	SI, DI
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	JGT	_forward
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	MOVL	SI, DX
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	ADDL	CX, DX
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	CMPL	DX, DI
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	JGT	_back
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_forward:
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	CLD
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	REP;	MOVSB
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	JMP	_startkernel
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_back:
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	ADDL	CX, DI
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	ADDL	CX, SI
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	SUBL	$1, DI
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	SUBL	$1, SI
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	STD
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	REP;	MOVSB
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	JMP	_startkernel
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/*
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 * JMP to kernel entry point.  Note the true kernel entry point is
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 * the virtual address KZERO|AX, but this must wait until
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 * the MMU is enabled by the kernel in l.s
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 */
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_startkernel:
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	ORL	AX, AX		/* NOP: avoid link bug */
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	JMP*	AX