setup.c

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/*
 *  linux/arch/i386/kernel/setup.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 *
 *  Enhanced CPU type detection by Mike Jagdis, Patrick St. Jean
 *  and Martin Mares, November 1997.
 *
 *  Force Cyrix 6x86(MX) and M II processors to report MTRR capability
 *  and Cyrix "coma bug" recognition by
 *      Zolt醤 B鰏z鰎m閚yi <[e-mail]> February 1999.
 * 
 *  Force Centaur C6 processors to report MTRR capability.
 *      Bart Hartgers <[e-mail]>, May 1999.
 *
 *  Intel Mobile Pentium II detection fix. Sean Gilley, June 1999.
 *
 *  IDT Winchip tweaks, misc clean ups.
 *	Dave Jones <[e-mail]>, August 1999
 *
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *
 *  Better detection of Centaur/IDT WinChip models.
 *      Bart Hartgers <[e-mail]>, August 1999.
 *
 *  Memory region support
 *	David Parsons <[e-mail]>, July-August 1999
 *
 *  Cleaned up cache-detection code
 *	Dave Jones <[e-mail]>, October 1999
 *
 *	Added proper L2 cache detection for Coppermine
 *	Dragan Stancevic <[e-mail]>, October 1999
 *
 *  Added the original array for capability flags but forgot to credit 
 *  myself :) (~1998) Fixed/cleaned up some cpu_model_info and other stuff
 *  	Jauder Ho <[e-mail]>, January 2000
 *
 *  Detection for Celeron coppermine, identify_cpu() overhauled,
 *  and a few other clean ups.
 *  Dave Jones <[e-mail]>, April 2000
 *
 *  Pentium III FXSR, SSE support
 *  General FPU state handling cleanups
 *	Gareth Hughes <[e-mail]>, May 2000
 *
 *  Added proper Cascades CPU and L2 cache detection for Cascades
 *  and 8-way type cache happy bunch from Intel:^)
 *  Dragan Stancevic <[e-mail]>, May 2000 
 *
 *  Forward port AMD Duron errata T13 from 2.2.17pre
 *  Dave Jones <[e-mail]>, August 2000
 *
 *  Forward port lots of fixes/improvements from 2.2.18pre
 *  Cyrix III, Pentium IV support.
 *  Dave Jones <[e-mail]>, October 2000
 *
 *  Massive cleanup of CPU detection and bug handling;
 *  Transmeta CPU detection,
 *  H. Peter Anvin <[e-mail]>, November 2000
 *
 *  Added E820 sanitization routine (removes overlapping memory regions);
 *  Brian Moyle <[e-mail]>, February 2001
 *
 *  VIA C3 Support.
 *  Dave Jones <[e-mail]>, March 2001
 *
 *  AMD Athlon/Duron/Thunderbird bluesmoke support.
 *  Dave Jones <[e-mail]>, April 2001.
 *
 *  CacheSize bug workaround updates for AMD, Intel & VIA Cyrix.
 *  Dave Jones <[e-mail]>, September, October 2001.
 *
 */

/*
 * 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/acpi.h>
#include <linux/apm_bios.h>
#ifdef CONFIG_BLK_DEV_RAM
#include <linux/blk.h>
#endif
#include <linux/highmem.h>
#include <linux/bootmem.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/seq_file.h>
#include <linux/console.h>
#include <asm/processor.h>
#include <asm/mtrr.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/cobalt.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>

/*
 * Machine setup..
 */

char ignore_irq13;		/* set if exception 16 works */
struct cpuinfo_x86 boot_cpu_data = { 0, 0, 0, 0, -1, 1, 0, 0, -1 };

unsigned long mmu_cr4_features;

/*
 * Bus types ..
 */
int MCA_bus;

/* for MCA, but anyone else can use it if they want */
unsigned int machine_id;
unsigned int machine_submodel_id;
unsigned int BIOS_revision;
unsigned int mca_pentium_flag;

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

/* user-defined highmem size */
static unsigned int highmem_pages = -1;

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

struct e820map e820;

unsigned char aux_device_present;

extern void mcheck_init(struct cpuinfo_x86 *c);
extern void dmi_scan_machine(void);
extern int root_mountflags;
extern char _text, _etext, _edata, _end;
extern int blk_nohighio;
void __init visws_get_board_type_and_rev(void);

static int disable_x86_serial_nr __initdata = 1;
static int disable_x86_fxsr __initdata = 0;

/*
 * This is set up by the setup-routine at boot-time
 */
#define PARAM	((unsigned char *)empty_zero_page)
#define SCREEN_INFO (*(struct screen_info *) (PARAM+0))
#define EXT_MEM_K (*(unsigned short *) (PARAM+2))
#define ALT_MEM_K (*(unsigned long *) (PARAM+0x1e0))
#define E820_MAP_NR (*(char*) (PARAM+E820NR))
#define E820_MAP    ((struct e820entry *) (PARAM+E820MAP))
#define APM_BIOS_INFO (*(struct apm_bios_info *) (PARAM+0x40))
#define DRIVE_INFO (*(struct drive_info_struct *) (PARAM+0x80))
#define SYS_DESC_TABLE (*(struct sys_desc_table_struct*)(PARAM+0xa0))
#define MOUNT_ROOT_RDONLY (*(unsigned short *) (PARAM+0x1F2))
#define RAMDISK_FLAGS (*(unsigned short *) (PARAM+0x1F8))
#define ORIG_ROOT_DEV (*(unsigned short *) (PARAM+0x1FC))
#define AUX_DEVICE_INFO (*(unsigned char *) (PARAM+0x1FF))
#define LOADER_TYPE (*(unsigned char *) (PARAM+0x210))
#define KERNEL_START (*(unsigned long *) (PARAM+0x214))
#define INITRD_START (*(unsigned long *) (PARAM+0x218))
#define INITRD_SIZE (*(unsigned long *) (PARAM+0x21c))
#define COMMAND_LINE ((char *) (PARAM+2048))
#define COMMAND_LINE_SIZE 256

#define RAMDISK_IMAGE_START_MASK  	0x07FF
#define RAMDISK_PROMPT_FLAG		0x8000
#define RAMDISK_LOAD_FLAG		0x4000	


static 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 }
};
#ifdef CONFIG_MELAN
standard_io_resources[1] = { "pic1", 0x20, 0x21, IORESOURCE_BUSY };
standard_io_resources[5] = { "pic2", 0xa0, 0xa1, IORESOURCE_BUSY };
#endif

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

static struct resource code_resource = { "Kernel code", 0x100000, 0 };
static struct resource data_resource = { "Kernel data", 0, 0 };
static 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 = isa_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 = isa_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 = isa_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);
	}
}

static void __init add_memory_region(unsigned long long start,
                                  unsigned long long size, int type)
{
	int x = e820.nr_map;

	if (x == E820MAX) {
	    printk(KERN_ERR "Ooops! Too many entries in the memory map!\n");
	    return;
	}

	e820.map[x].addr = start;
	e820.map[x].size = size;
	e820.map[x].type = type;
	e820.nr_map++;
} /* add_memory_region */

#define E820_DEBUG	1

static void __init print_memory_map(char *who)
{
	int i;

	for (i = 0; i < e820.nr_map; i++) {
		printk(" %s: %016Lx - %016Lx ", who,
			e820.map[i].addr,
			e820.map[i].addr + e820.map[i].size);
		switch (e820.map[i].type) {
		case E820_RAM:	printk("(usable)\n");
				break;
		case E820_RESERVED:
				printk("(reserved)\n");
				break;
		case E820_ACPI:
				printk("(ACPI data)\n");
				break;
		case E820_NVS:
				printk("(ACPI NVS)\n");
				break;
		default:	printk("type %lu\n", e820.map[i].type);
				break;
		}
	}
}

/*
 * Sanitize the BIOS e820 map.
 *
 * Some e820 responses include overlapping entries.  The following 
 * replaces the original e820 map with a new one, removing overlaps.
 *
 */
static int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
{
	struct change_member {
		struct e820entry *pbios; /* pointer to original bios entry */
		unsigned long long addr; /* address for this change point */
	};
	struct change_member change_point_list[2*E820MAX];
	struct change_member *change_point[2*E820MAX];
	struct e820entry *overlap_list[E820MAX];
	struct e820entry new_bios[E820MAX];
	struct change_member *change_tmp;
	unsigned long current_type, last_type;
	unsigned long long last_addr;
	int chgidx, still_changing;
	int overlap_entries;
	int new_bios_entry;
	int old_nr, new_nr;
	int i;

	/*
		Visually we're performing the following (1,2,3,4 = memory types)...

		Sample memory map (w/overlaps):
		   ____22__________________
		   ______________________4_
		   ____1111________________
		   _44_____________________
		   11111111________________
		   ____________________33__
		   ___________44___________
		   __________33333_________
		   ______________22________
		   ___________________2222_
		   _________111111111______
		   _____________________11_
		   _________________4______

		Sanitized equivalent (no overlap):
		   1_______________________
		   _44_____________________
		   ___1____________________
		   ____22__________________
		   ______11________________
		   _________1______________
		   __________3_____________
		   ___________44___________
		   _____________33_________
		   _______________2________
		   ________________1_______
		   _________________4______
		   ___________________2____
		   ____________________33__
		   ______________________4_
	*/

	/* if there's only one memory region, don't bother */
	if (*pnr_map < 2)
		return -1;

	old_nr = *pnr_map;

	/* bail out if we find any unreasonable addresses in bios map */
	for (i=0; i<old_nr; i++)
		if (biosmap[i].addr + biosmap[i].size < biosmap[i].addr)
			return -1;

	/* create pointers for initial change-point information (for sorting) */
	for (i=0; i < 2*old_nr; i++)
		change_point[i] = &change_point_list[i];

	/* record all known change-points (starting and ending addresses) */
	chgidx = 0;
	for (i=0; i < old_nr; i++)	{
		change_point[chgidx]->addr = biosmap[i].addr;
		change_point[chgidx++]->pbios = &biosmap[i];
		change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
		change_point[chgidx++]->pbios = &biosmap[i];
	}

	/* sort change-point list by memory addresses (low -> high) */
	still_changing = 1;
	while (still_changing)	{
		still_changing = 0;
		for (i=1; i < 2*old_nr; i++)  {
			/* if <current_addr> > <last_addr>, swap */
			/* or, if current=<start_addr> & last=<end_addr>, swap */
			if ((change_point[i]->addr < change_point[i-1]->addr) ||
				((change_point[i]->addr == change_point[i-1]->addr) &&
				 (change_point[i]->addr == change_point[i]->pbios->addr) &&
				 (change_point[i-1]->addr != change_point[i-1]->pbios->addr))
			   )
			{
				change_tmp = change_point[i];
				change_point[i] = change_point[i-1];
				change_point[i-1] = change_tmp;
				still_changing=1;
			}
		}
	}

	/* create a new bios memory map, removing overlaps */
	overlap_entries=0;	 /* number of entries in the overlap table */
	new_bios_entry=0;	 /* index for creating new bios map entries */
	last_type = 0;		 /* start with undefined memory type */
	last_addr = 0;		 /* start with 0 as last starting address */
	/* loop through change-points, determining affect on the new bios map */
	for (chgidx=0; chgidx < 2*old_nr; chgidx++)
	{
		/* keep track of all overlapping bios entries */
		if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
		{
			/* add map entry to overlap list (> 1 entry implies an overlap) */
			overlap_list[overlap_entries++]=change_point[chgidx]->pbios;
		}
		else
		{
			/* remove entry from list (order independent, so swap with last) */
			for (i=0; i<overlap_entries; i++)
			{
				if (overlap_list[i] == change_point[chgidx]->pbios)
					overlap_list[i] = overlap_list[overlap_entries-1];
			}
			overlap_entries--;
		}
		/* if there are overlapping entries, decide which "type" to use */
		/* (larger value takes precedence -- 1=usable, 2,3,4,4+=unusable) */
		current_type = 0;
		for (i=0; i<overlap_entries; i++)
			if (overlap_list[i]->type > current_type)
				current_type = overlap_list[i]->type;
		/* continue building up new bios map based on this information */
		if (current_type != last_type)	{
			if (last_type != 0)	 {
				new_bios[new_bios_entry].size =
					change_point[chgidx]->addr - last_addr;
				/* move forward only if the new size was non-zero */
				if (new_bios[new_bios_entry].size != 0)
					if (++new_bios_entry >= E820MAX)
						break; 	/* no more space left for new bios entries */
			}
			if (current_type != 0)	{
				new_bios[new_bios_entry].addr = change_point[chgidx]->addr;
				new_bios[new_bios_entry].type = current_type;
				last_addr=change_point[chgidx]->addr;
			}
			last_type = current_type;
		}
	}