__asm__ __volatile__ ("lgdt %0" : : "m" (real_mode_gdt)); 
load_gdt(&real_mode_gdt); 
void machine_real_restart(unsigned char *code, int length){	unsigned long flags;	local_irq_disable();	/* Write zero to CMOS register number 0x0f, which the BIOS POST	   routine will recognize as telling it to do a proper reboot.  (Well	   that's what this book in front of me says -- it may only apply to	   the Phoenix BIOS though, it's not clear).  At the same time,	   disable NMIs by setting the top bit in the CMOS address register,	   as we're about to do peculiar things to the CPU.  I'm not sure if	   `outb_p' is needed instead of just `outb'.  Use it to be on the	   safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)	 */	spin_lock_irqsave(&rtc_lock, flags);	CMOS_WRITE(0x00, 0x8f);	spin_unlock_irqrestore(&rtc_lock, flags);	/* Remap the kernel at virtual address zero, as well as offset zero	   from the kernel segment.  This assumes the kernel segment starts at	   virtual address PAGE_OFFSET. */	memcpy (swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,		sizeof (swapper_pg_dir [0]) * KERNEL_PGD_PTRS);	/*	 * Use `swapper_pg_dir' as our page directory.	 */	load_cr3(swapper_pg_dir);	/* Write 0x1234 to absolute memory location 0x472.  The BIOS reads	   this on booting to tell it to "Bypass memory test (also warm	   boot)".  This seems like a fairly standard thing that gets set by	   REBOOT.COM programs, and the previous reset routine did this	   too. */	*((unsigned short *)0x472) = reboot_mode;	/* For the switch to real mode, copy some code to low memory.  It has	   to be in the first 64k because it is running in 16-bit mode, and it	   has to have the same physical and virtual address, because it turns	   off paging.  Copy it near the end of the first page, out of the way	   of BIOS variables. */	memcpy ((void *) (0x1000 - sizeof (real_mode_switch) - 100),		real_mode_switch, sizeof (real_mode_switch));	memcpy ((void *) (0x1000 - 100), code, length);	/* Set up the IDT for real mode. */	__asm__ __volatile__ ("lidt %0" : : "m" (real_mode_idt));	/* Set up a GDT from which we can load segment descriptors for real	   mode.  The GDT is not used in real mode; it is just needed here to	   prepare the descriptors. */	__asm__ __volatile__ ("lgdt %0" : : "m" (real_mode_gdt));	/* Load the data segment registers, and thus the descriptors ready for	   real mode.  The base address of each segment is 0x100, 16 times the	   selector value being loaded here.  This is so that the segment	   registers don't have to be reloaded after switching to real mode:	   the values are consistent for real mode operation already. */	__asm__ __volatile__ ("movl $0x0010,%%eax\n"				"\tmovl %%eax,%%ds\n"				"\tmovl %%eax,%%es\n"				"\tmovl %%eax,%%fs\n"				"\tmovl %%eax,%%gs\n"				"\tmovl %%eax,%%ss" : : : "eax");	/* Jump to the 16-bit code that we copied earlier.  It disables paging	   and the cache, switches to real mode, and jumps to the BIOS reset	   entry point. */	__asm__ __volatile__ ("ljmp $0x0008,%0"				:				: "i" ((void *) (0x1000 - sizeof (real_mode_switch) - 100)));}
10457	/local/tlutelli/issta_data/temp/c/2005_temp/2005/10457/4d37e7e3fd851428dede4d05d3e69d03795a744a/reboot.c/buggy/arch/i386/kernel/reboot.c