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98 cejka 1 
/*
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 * Copyright (C) 2005 Josef Cejka
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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#include <arch/boot/memmapasm.h>
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E820_SMAP = 0x534d4150
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.global memmap_arch_init
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.global e801memorysize
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.code16
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.section K_TEXT_START_2, "ax"
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memmap_arch_init:
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e820begin:
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	xorl	%ebx,%ebx			# during first call, ebx must be 0
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	movw	$e820table_boot,%di
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	movb	$MEMMAP_E820_MAX_RECORDS,e820counter_boot
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e820loop:
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	movl	$E820_SMAP,%edx 		# control sequence "SMAP"
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	movl	$0x0000e820,%eax		# service
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	movl	$MEMMAP_E820_RECORD_SIZE,%ecx
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	int 	$0x15
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	jc	e820err
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	cmpl	$E820_SMAP,%eax			# verifying BIOS
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	jne	e820err
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	cmpl	$MEMMAP_E820_RECORD_SIZE,%ecx
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	jne	e820err				# bad record size - bug in bios
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	movw	%di,%ax				# next record
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	addw	$MEMMAP_E820_RECORD_SIZE,%ax
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	movw	%ax,%di
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	decb	e820counter_boot 		# buffer is full
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	jz	e820end
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	testl	%ebx,%ebx
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	jnz	e820loop
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e820end:
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	movb	$MEMMAP_E820_MAX_RECORDS,%al
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	subb	e820counter_boot,%al
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	movb	%al,e820counter_boot 		# store # of valid entries in e820counter
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	jmp	e801begin
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e820err:
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	movb	$0,e820counter_boot
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# method e801 - get size of memory
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e801begin:
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	xorw	%dx,%dx
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	xorw	%cx,%cx
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	xorw	%bx,%bx
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	movw	$0xe801,%ax
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	stc
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	int	$0x15
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	jc	e801end
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	# fix problem with some BIOSes which use ax:bx rather than cx:dx
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	testw	%cx,%cx
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	jnz	e801cxdx
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	testw	%dx,%dx
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	jnz	e801cxdx
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	movw	%ax,%cx
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	movw	%bx,%dx
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e801cxdx:
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	andl	$0xffff,%edx
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	shll	$6,%edx
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	andl	$0xffff,%ecx
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	addl	%ecx,%edx
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	addl	$0x0400,%edx  			# add lower 1 MB - it's not included by e801 method
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	movl	%edx,e801memorysize
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e801end:
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	ret
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.section K_DATA_START, "aw", @progbits
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#memory size in 1 kb chunks
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e801memorysize:
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	.long	0