setup_32.c

linux 内核源代码

	max_mapnr = num_physpages;
#endif
	printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
			pages_to_mb(max_low_pfn));

	setup_bootmem_allocator();

	return max_low_pfn;
}

void __init zone_sizes_init(void)
{
	unsigned long max_zone_pfns[MAX_NR_ZONES];
	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
	max_zone_pfns[ZONE_DMA] =
		virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
#ifdef CONFIG_HIGHMEM
	max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
	add_active_range(0, 0, highend_pfn);
#else
	add_active_range(0, 0, max_low_pfn);
#endif

	free_area_init_nodes(max_zone_pfns);
}
#else
extern unsigned long __init setup_memory(void);
extern void zone_sizes_init(void);
#endif /* !CONFIG_NEED_MULTIPLE_NODES */

static inline unsigned long long get_total_mem(void)
{
	unsigned long long total;

	total = max_low_pfn - min_low_pfn;
#ifdef CONFIG_HIGHMEM
	total += highend_pfn - highstart_pfn;
#endif

	return total << PAGE_SHIFT;
}

#ifdef CONFIG_KEXEC
static void __init reserve_crashkernel(void)
{
	unsigned long long total_mem;
	unsigned long long crash_size, crash_base;
	int ret;

	total_mem = get_total_mem();

	ret = parse_crashkernel(boot_command_line, total_mem,
			&crash_size, &crash_base);
	if (ret == 0 && crash_size > 0) {
		if (crash_base > 0) {
			printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
					"for crashkernel (System RAM: %ldMB)\n",
					(unsigned long)(crash_size >> 20),
					(unsigned long)(crash_base >> 20),
					(unsigned long)(total_mem >> 20));
			crashk_res.start = crash_base;
			crashk_res.end   = crash_base + crash_size - 1;
			reserve_bootmem(crash_base, crash_size);
		} else
			printk(KERN_INFO "crashkernel reservation failed - "
					"you have to specify a base address\n");
	}
}
#else
static inline void __init reserve_crashkernel(void)
{}
#endif

void __init setup_bootmem_allocator(void)
{
	unsigned long bootmap_size;
	/*
	 * Initialize the boot-time allocator (with low memory only):
	 */
	bootmap_size = init_bootmem(min_low_pfn, max_low_pfn);

	register_bootmem_low_pages(max_low_pfn);

	/*
	 * Reserve the bootmem bitmap itself as well. We do this in two
	 * steps (first step was init_bootmem()) because this catches
	 * the (very unlikely) case of us accidentally initializing the
	 * bootmem allocator with an invalid RAM area.
	 */
	reserve_bootmem(__pa_symbol(_text), (PFN_PHYS(min_low_pfn) +
			 bootmap_size + PAGE_SIZE-1) - __pa_symbol(_text));

	/*
	 * reserve physical page 0 - it's a special BIOS page on many boxes,
	 * enabling clean reboots, SMP operation, laptop functions.
	 */
	reserve_bootmem(0, PAGE_SIZE);

	/* reserve EBDA region, it's a 4K region */
	reserve_ebda_region();

    /* could be an AMD 768MPX chipset. Reserve a page  before VGA to prevent
       PCI prefetch into it (errata #56). Usually the page is reserved anyways,
       unless you have no PS/2 mouse plugged in. */
	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
	    boot_cpu_data.x86 == 6)
	     reserve_bootmem(0xa0000 - 4096, 4096);

#ifdef CONFIG_SMP
	/*
	 * But first pinch a few for the stack/trampoline stuff
	 * FIXME: Don't need the extra page at 4K, but need to fix
	 * trampoline before removing it. (see the GDT stuff)
	 */
	reserve_bootmem(PAGE_SIZE, PAGE_SIZE);
#endif
#ifdef CONFIG_ACPI_SLEEP
	/*
	 * Reserve low memory region for sleep support.
	 */
	acpi_reserve_bootmem();
#endif
#ifdef CONFIG_X86_FIND_SMP_CONFIG
	/*
	 * Find and reserve possible boot-time SMP configuration:
	 */
	find_smp_config();
#endif
	numa_kva_reserve();
#ifdef CONFIG_BLK_DEV_INITRD
	if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
		unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
		unsigned long ramdisk_size  = boot_params.hdr.ramdisk_size;
		unsigned long ramdisk_end   = ramdisk_image + ramdisk_size;
		unsigned long end_of_lowmem = max_low_pfn << PAGE_SHIFT;

		if (ramdisk_end <= end_of_lowmem) {
			reserve_bootmem(ramdisk_image, ramdisk_size);
			initrd_start = ramdisk_image + PAGE_OFFSET;
			initrd_end = initrd_start+ramdisk_size;
		} else {
			printk(KERN_ERR "initrd extends beyond end of memory "
			       "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
			       ramdisk_end, end_of_lowmem);
			initrd_start = 0;
		}
	}
#endif
	reserve_crashkernel();
}

/*
 * The node 0 pgdat is initialized before all of these because
 * it's needed for bootmem.  node>0 pgdats have their virtual
 * space allocated before the pagetables are in place to access
 * them, so they can't be cleared then.
 *
 * This should all compile down to nothing when NUMA is off.
 */
static void __init remapped_pgdat_init(void)
{
	int nid;

	for_each_online_node(nid) {
		if (nid != 0)
			memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));
	}
}

#ifdef CONFIG_MCA
static void set_mca_bus(int x)
{
	MCA_bus = x;
}
#else
static void set_mca_bus(int x) { }
#endif

/* Overridden in paravirt.c if CONFIG_PARAVIRT */
char * __init __attribute__((weak)) memory_setup(void)
{
	return machine_specific_memory_setup();
}

/*
 * Determine if we were loaded by an EFI loader.  If so, then we have also been
 * passed the efi memmap, systab, etc., so we should use these data structures
 * for initialization.  Note, the efi init code path is determined by the
 * global efi_enabled. This allows the same kernel image to be used on existing
 * systems (with a traditional BIOS) as well as on EFI systems.
 */
void __init setup_arch(char **cmdline_p)
{
	unsigned long max_low_pfn;

	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
	pre_setup_arch_hook();
	early_cpu_init();

	/*
	 * FIXME: This isn't an official loader_type right
	 * now but does currently work with elilo.
	 * If we were configured as an EFI kernel, check to make
	 * sure that we were loaded correctly from elilo and that
	 * the system table is valid.  If not, then initialize normally.
	 */
#ifdef CONFIG_EFI
	if ((boot_params.hdr.type_of_loader == 0x50) &&
	    boot_params.efi_info.efi_systab)
		efi_enabled = 1;
#endif

	ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
	screen_info = boot_params.screen_info;
	edid_info = boot_params.edid_info;
	apm_info.bios = boot_params.apm_bios_info;
	ist_info = boot_params.ist_info;
	saved_videomode = boot_params.hdr.vid_mode;
	if( boot_params.sys_desc_table.length != 0 ) {
		set_mca_bus(boot_params.sys_desc_table.table[3] & 0x2);
		machine_id = boot_params.sys_desc_table.table[0];
		machine_submodel_id = boot_params.sys_desc_table.table[1];
		BIOS_revision = boot_params.sys_desc_table.table[2];
	}
	bootloader_type = boot_params.hdr.type_of_loader;

#ifdef CONFIG_BLK_DEV_RAM
	rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
	rd_prompt = ((boot_params.hdr.ram_size & RAMDISK_PROMPT_FLAG) != 0);
	rd_doload = ((boot_params.hdr.ram_size & RAMDISK_LOAD_FLAG) != 0);
#endif
	ARCH_SETUP
	if (efi_enabled)
		efi_init();
	else {
		printk(KERN_INFO "BIOS-provided physical RAM map:\n");
		print_memory_map(memory_setup());
	}

	copy_edd();

	if (!boot_params.hdr.root_flags)
		root_mountflags &= ~MS_RDONLY;
	init_mm.start_code = (unsigned long) _text;
	init_mm.end_code = (unsigned long) _etext;
	init_mm.end_data = (unsigned long) _edata;
	init_mm.brk = init_pg_tables_end + PAGE_OFFSET;

	code_resource.start = virt_to_phys(_text);
	code_resource.end = virt_to_phys(_etext)-1;
	data_resource.start = virt_to_phys(_etext);
	data_resource.end = virt_to_phys(_edata)-1;
	bss_resource.start = virt_to_phys(&__bss_start);
	bss_resource.end = virt_to_phys(&__bss_stop)-1;

	parse_early_param();

	if (user_defined_memmap) {
		printk(KERN_INFO "user-defined physical RAM map:\n");
		print_memory_map("user");
	}

	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
	*cmdline_p = command_line;

	max_low_pfn = setup_memory();

#ifdef CONFIG_VMI
	/*
	 * Must be after max_low_pfn is determined, and before kernel
	 * pagetables are setup.
	 */
	vmi_init();
#endif

	/*
	 * NOTE: before this point _nobody_ is allowed to allocate
	 * any memory using the bootmem allocator.  Although the
	 * allocator is now initialised only the first 8Mb of the kernel
	 * virtual address space has been mapped.  All allocations before
	 * paging_init() has completed must use the alloc_bootmem_low_pages()
	 * variant (which allocates DMA'able memory) and care must be taken
	 * not to exceed the 8Mb limit.
	 */

#ifdef CONFIG_SMP
	smp_alloc_memory(); /* AP processor realmode stacks in low memory*/
#endif
	paging_init();
	remapped_pgdat_init();
	sparse_init();
	zone_sizes_init();

	/*
	 * NOTE: at this point the bootmem allocator is fully available.
	 */

	paravirt_post_allocator_init();

	dmi_scan_machine();

#ifdef CONFIG_X86_GENERICARCH
	generic_apic_probe();
#endif	
	if (efi_enabled)
		efi_map_memmap();

#ifdef CONFIG_ACPI
	/*
	 * Parse the ACPI tables for possible boot-time SMP configuration.
	 */
	acpi_boot_table_init();
#endif

#ifdef CONFIG_PCI
	early_quirks();
#endif

#ifdef CONFIG_ACPI
	acpi_boot_init();

#if defined(CONFIG_SMP) && defined(CONFIG_X86_PC)
	if (def_to_bigsmp)
		printk(KERN_WARNING "More than 8 CPUs detected and "
			"CONFIG_X86_PC cannot handle it.\nUse "
			"CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP.\n");
#endif
#endif
#ifdef CONFIG_X86_LOCAL_APIC
	if (smp_found_config)
		get_smp_config();
#endif

	e820_register_memory();
	e820_mark_nosave_regions();

#ifdef CONFIG_VT
#if defined(CONFIG_VGA_CONSOLE)
	if (!efi_enabled || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
		conswitchp = &vga_con;
#elif defined(CONFIG_DUMMY_CONSOLE)
	conswitchp = &dummy_con;
#endif
#endif
}