setup.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

/*
 *  linux/arch/x86-64/kernel/setup.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 *
 *  Nov 2001 Dave Jones <[e-mail]>
 *  Forked from i386 setup code.
 */

/*
 * This file handles the architecture-dependent parts of initialization
 */

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/tty.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/config.h>
#include <linux/init.h>
#include <linux/blk.h>
#include <linux/highmem.h>
#include <linux/bootmem.h>
#include <asm/processor.h>
#include <linux/console.h>
#include <linux/seq_file.h>
#include <asm/mtrr.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/msr.h>
#include <asm/desc.h>
#include <asm/e820.h>
#include <asm/dma.h>
#include <asm/mpspec.h>
#include <asm/mmu_context.h>
#include <asm/bootsetup.h>
#include <asm/proto.h>

/*
 * Machine setup..
 */

struct cpuinfo_x86 boot_cpu_data = { 
	cpuid_level: -1, 
};

unsigned long mmu_cr4_features;

/* For PCI or other memory-mapped resources */
unsigned long pci_mem_start = 0x10000000;

/*
 * Setup options
 */
struct drive_info_struct { char dummy[32]; } drive_info;
struct screen_info screen_info;
struct sys_desc_table_struct {
	unsigned short length;
	unsigned char table[0];
};

struct e820map e820;

unsigned char aux_device_present;

extern int root_mountflags;
extern char _text, _etext, _edata, _end;

static int disable_x86_fxsr __initdata = 0;

char command_line[COMMAND_LINE_SIZE];
char saved_command_line[COMMAND_LINE_SIZE];

struct resource standard_io_resources[] = {
	{ "dma1", 0x00, 0x1f, IORESOURCE_BUSY },
	{ "pic1", 0x20, 0x3f, IORESOURCE_BUSY },
	{ "timer", 0x40, 0x5f, IORESOURCE_BUSY },
	{ "keyboard", 0x60, 0x6f, IORESOURCE_BUSY },
	{ "dma page reg", 0x80, 0x8f, IORESOURCE_BUSY },
	{ "pic2", 0xa0, 0xbf, IORESOURCE_BUSY },
	{ "dma2", 0xc0, 0xdf, IORESOURCE_BUSY },
	{ "fpu", 0xf0, 0xff, IORESOURCE_BUSY }
};

#define STANDARD_IO_RESOURCES (sizeof(standard_io_resources)/sizeof(struct resource))

struct resource code_resource = { "Kernel code", 0x100000, 0 };
struct resource data_resource = { "Kernel data", 0, 0 };
struct resource vram_resource = { "Video RAM area", 0xa0000, 0xbffff, IORESOURCE_BUSY };


/* System ROM resources */
#define MAXROMS 6
static struct resource rom_resources[MAXROMS] = {
	{ "System ROM", 0xF0000, 0xFFFFF, IORESOURCE_BUSY },
	{ "Video ROM", 0xc0000, 0xc7fff, IORESOURCE_BUSY }
};

#define romsignature(x) (*(unsigned short *)(x) == 0xaa55)

static void __init probe_roms(void)
{
	int roms = 1;
	unsigned long base;
	unsigned char *romstart;

	request_resource(&iomem_resource, rom_resources+0);

	/* Video ROM is standard at C000:0000 - C7FF:0000, check signature */
	for (base = 0xC0000; base < 0xE0000; base += 2048) {
		romstart = bus_to_virt(base);
		if (!romsignature(romstart))
			continue;
		request_resource(&iomem_resource, rom_resources + roms);
		roms++;
		break;
	}

	/* Extension roms at C800:0000 - DFFF:0000 */
	for (base = 0xC8000; base < 0xE0000; base += 2048) {
		unsigned long length;

		romstart = bus_to_virt(base);
		if (!romsignature(romstart))
			continue;
		length = romstart[2] * 512;
		if (length) {
			unsigned int i;
			unsigned char chksum;

			chksum = 0;
			for (i = 0; i < length; i++)
				chksum += romstart[i];

			/* Good checksum? */
			if (!chksum) {
				rom_resources[roms].start = base;
				rom_resources[roms].end = base + length - 1;
				rom_resources[roms].name = "Extension ROM";
				rom_resources[roms].flags = IORESOURCE_BUSY;

				request_resource(&iomem_resource, rom_resources + roms);
				roms++;
				if (roms >= MAXROMS)
					return;
			}
		}
	}

	/* Final check for motherboard extension rom at E000:0000 */
	base = 0xE0000;
	romstart = bus_to_virt(base);

	if (romsignature(romstart)) {
		rom_resources[roms].start = base;
		rom_resources[roms].end = base + 65535;
		rom_resources[roms].name = "Extension ROM";
		rom_resources[roms].flags = IORESOURCE_BUSY;

		request_resource(&iomem_resource, rom_resources + roms);
	}
}

unsigned long start_pfn, end_pfn; 
extern unsigned long table_start, table_end;

#ifndef CONFIG_DISCONTIGMEM
static void __init contig_initmem_init(void)
{
	unsigned long bootmap_size, bootmap; 
	bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
	bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size);
	if (bootmap == -1L) 
		panic("Cannot find bootmem map of size %ld\n",bootmap_size);
	bootmap_size = init_bootmem(bootmap >> PAGE_SHIFT, end_pfn);
	e820_bootmem_free(&contig_page_data, 0, end_pfn << PAGE_SHIFT); 
	reserve_bootmem(bootmap, bootmap_size);
}
#endif

void __init setup_arch(char **cmdline_p)
{
	int i;
	unsigned long kernel_end; 

 	ROOT_DEV = to_kdev_t(ORIG_ROOT_DEV);
 	drive_info = DRIVE_INFO;
 	screen_info = SCREEN_INFO;
	aux_device_present = AUX_DEVICE_INFO;

#ifdef CONFIG_BLK_DEV_RAM
	rd_image_start = RAMDISK_FLAGS & RAMDISK_IMAGE_START_MASK;
	rd_prompt = ((RAMDISK_FLAGS & RAMDISK_PROMPT_FLAG) != 0);
	rd_doload = ((RAMDISK_FLAGS & RAMDISK_LOAD_FLAG) != 0);
#endif
	setup_memory_region();

	if (!MOUNT_ROOT_RDONLY)
		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 = (unsigned long) &_end;

	code_resource.start = virt_to_bus(&_text);
	code_resource.end = virt_to_bus(&_etext)-1;
	data_resource.start = virt_to_bus(&_etext);
	data_resource.end = virt_to_bus(&_edata)-1;

	parse_mem_cmdline(cmdline_p);

	e820_end_of_ram();

	init_memory_mapping(); 

#ifdef CONFIG_BLK_DEV_INITRD
	if (LOADER_TYPE && INITRD_START) {
		if (INITRD_START + INITRD_SIZE <= (end_pfn << PAGE_SHIFT)) {
			initrd_start =
				INITRD_START ? INITRD_START + PAGE_OFFSET : 0;
			initrd_end = initrd_start+INITRD_SIZE;
	}
		else {
			printk(KERN_ERR "initrd extends beyond end of memory "
			    "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
			    (unsigned long)INITRD_START + INITRD_SIZE,
			    (unsigned long)(end_pfn << PAGE_SHIFT));
			initrd_start = 0;
	}
	}
#endif

#ifdef CONFIG_DISCONTIGMEM
	numa_initmem_init(0, end_pfn); 	
#else
	contig_initmem_init(); 
#endif	

	/* Reserve direct mapping */
	reserve_bootmem_generic(table_start << PAGE_SHIFT, 
				(table_end - table_start) << PAGE_SHIFT);

#ifdef CONFIG_BLK_DEV_INITRD
	if (initrd_start) 
		reserve_bootmem_generic(INITRD_START, INITRD_SIZE);
#endif

	/* Reserve BIOS data page. Some things still need it */
	reserve_bootmem_generic(0, PAGE_SIZE);

#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_generic(PAGE_SIZE, PAGE_SIZE); 

	/* Reserve SMP trampoline */
	reserve_bootmem_generic(0x6000, PAGE_SIZE);
#endif
	/* Reserve Kernel */
	kernel_end = round_up(__pa_symbol(&_end), PAGE_SIZE);
	reserve_bootmem_generic(HIGH_MEMORY, kernel_end - HIGH_MEMORY);

#ifdef CONFIG_X86_LOCAL_APIC
	/*
	 * Find and reserve possible boot-time SMP configuration:
	 */
	find_smp_config();
#endif

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

	paging_init();
#ifdef CONFIG_X86_LOCAL_APIC
	/*
	 * get boot-time SMP configuration:
	 */
	if (smp_found_config)
		get_smp_config();
	init_apic_mappings();	
#endif

	/*
	 * Request address space for all standard RAM and ROM resources
	 * and also for regions reported as reserved by the e820.
	 */
	probe_roms();
	e820_reserve_resources(); 
	request_resource(&iomem_resource, &vram_resource);

	/* request I/O space for devices used on all i[345]86 PCs */
	for (i = 0; i < STANDARD_IO_RESOURCES; i++)
		request_resource(&ioport_resource, standard_io_resources+i);

	/* We put PCI memory up to make sure VALID_PAGE with DISCONTIGMEM
	   never returns true for it */ 

	/* Tell the PCI layer not to allocate too close to the RAM area.. */
	pci_mem_start = IOMAP_START;

#ifdef CONFIG_GART_IOMMU
	iommu_hole_init();
#endif

#ifdef CONFIG_VT
#if defined(CONFIG_VGA_CONSOLE)
	conswitchp = &vga_con;
#elif defined(CONFIG_DUMMY_CONSOLE)
	conswitchp = &dummy_con;
#endif
#endif

	num_mappedpages = end_pfn;
}

#ifndef CONFIG_X86_TSC
static int tsc_disable __initdata = 0;

static int __init tsc_setup(char *str)
{
	tsc_disable = 1;
	return 1;
}

__setup("notsc", tsc_setup);
#endif

static int __init get_model_name(struct cpuinfo_x86 *c)
{