do_env.c

阿基米德操作系统的源代码

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#include "general.h"

#include "hd_info_struct.h"
#include "dir_entry.h"
#include "msdos_dir_entry.h"
#include "d_inode.h"
#include "m_inode.h"
#include "buffer_head.h"
#include "fat_cache.h"
#include "file.h"
#include "hd_request_struct.h"
#include "super_block.h"

#include "common_head.h"
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void backup_env(unsigned long the_entry)
{
	unsigned long * temp_pLong;
	int temp_i;

	temp_pLong	= (unsigned long *)kernel_stack;
	temp_pLong	= temp_pLong + 2032;

	for (temp_i = 0; temp_i < 16; temp_i++)
		old_REGS[temp_i] = temp_pLong[temp_i];

	temp_pLong[15]	=	0x33;										////old SS
	temp_pLong[14]	=	((unsigned long)exec_stackptr) - 0x800000;	////old ESP
	temp_pLong[13]	=	(temp_pLong[13] & 0xffffbaff) | 0x00000200;	////old EFLAGS
	temp_pLong[12]	=	0x2b;										////old CS
	temp_pLong[11]	=	the_entry;									////old EIP
	temp_pLong[10]	=	0x33;										////GS
	temp_pLong[9]	=	0x33;										////FS
	temp_pLong[8]	=	0x33;										////ES
	temp_pLong[7]	=	0x33;										////DS
	temp_pLong[6]	=	0;											////EBP
	temp_pLong[5]	=	0;											////EDI
	temp_pLong[4]	=	0;											////ESI
	temp_pLong[3]	=	0;											////EDX
	temp_pLong[2]	=	0;											////ECX
	temp_pLong[1]	=	0;											////EBX
	temp_pLong[0]	=	0;											////EAX
	
	return;
}

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void restore_env(void)
{
	unsigned long * temp_pLong;
	int temp_i;

	temp_pLong	= (unsigned long *)kernel_stack;
	temp_pLong	= temp_pLong + 2032;

	for (temp_i = 0; temp_i < 16; temp_i++)
		temp_pLong[temp_i] = old_REGS[temp_i];

	return;
}

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