setup.c

一个2.4.21版本的嵌入式linux内核

/*
 *  linux/arch/alpha/kernel/setup.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 */

/* 2.3.x bootmem, 1999 Andrea Arcangeli <[e-mail]> */

/*
 * Bootup setup stuff.
 */

#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/delay.h>
#include <linux/config.h>	/* CONFIG_ALPHA_LCA etc */
#include <linux/mc146818rtc.h>
#include <linux/console.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/bootmem.h>
#include <linux/pci.h>
#include <linux/seq_file.h>

#ifdef CONFIG_BLK_DEV_INITRD
#include <linux/blk.h>
#endif

#include <linux/notifier.h>
extern struct notifier_block *panic_notifier_list;
static int alpha_panic_event(struct notifier_block *, unsigned long, void *);
static struct notifier_block alpha_panic_block = {
	alpha_panic_event,
        NULL,
        INT_MAX /* try to do it first */
};

#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/hwrpb.h>
#include <asm/dma.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/console.h>

#include "proto.h"
#include "pci_impl.h"


struct hwrpb_struct *hwrpb;
unsigned long srm_hae;

/* Which processor we booted from.  */
int boot_cpuid;

/*
 * Using SRM callbacks for initial console output. This works from
 * setup_arch() time through the end of time_init(), as those places
 * are under our (Alpha) control.

 * "srmcons" specified in the boot command arguments allows us to
 * see kernel messages during the period of time before the true
 * console device is "registered" during console_init(). 
 * As of this version (2.4.20), console_init() will call
 * disable_early_printk() as the last action before initializing
 * the console drivers. That's the last possible time srmcons can be 
 * unregistered without interfering with console behavior.
 *
 * By default, OFF; set it with a bootcommand arg of "srmcons" or 
 * "console=srm". The meaning of these two args is:
 *     "srmcons"     - early callback prints 
 *     "console=srm" - full callback based console, including early prints
 */
int srmcons_output = 0;

/* Enforce a memory size limit; useful for testing. By default, none. */
unsigned long mem_size_limit = 0;

/* Set AGP GART window size (0 means disabled). */
unsigned long alpha_agpgart_size = DEFAULT_AGP_APER_SIZE;

#ifdef CONFIG_ALPHA_GENERIC
struct alpha_machine_vector alpha_mv;
int alpha_using_srm;
#endif

unsigned char aux_device_present = 0xaa;

#define N(a) (sizeof(a)/sizeof(a[0]))

static struct alpha_machine_vector *get_sysvec(long, long, long);
static struct alpha_machine_vector *get_sysvec_byname(const char *);
static void get_sysnames(long, long, long, char **, char **);

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

/*
 * The format of "screen_info" is strange, and due to early
 * i386-setup code. This is just enough to make the console
 * code think we're on a VGA color display.
 */

struct screen_info screen_info = {
	orig_x: 0,
	orig_y: 25,
	orig_video_cols: 80,
	orig_video_lines: 25,
	orig_video_isVGA: 1,
	orig_video_points: 16
};

/*
 * The direct map I/O window, if any.  This should be the same
 * for all busses, since it's used by virt_to_bus.
 */

unsigned long __direct_map_base;
unsigned long __direct_map_size;

/*
 * Declare all of the machine vectors.
 */

/* GCC 2.7.2 (on alpha at least) is lame.  It does not support either 
   __attribute__((weak)) or #pragma weak.  Bypass it and talk directly
   to the assembler.  */

#define WEAK(X) \
	extern struct alpha_machine_vector X; \
	asm(".weak "#X)

WEAK(alcor_mv);
WEAK(alphabook1_mv);
WEAK(avanti_mv);
WEAK(cabriolet_mv);
WEAK(clipper_mv);
WEAK(dp264_mv);
WEAK(eb164_mv);
WEAK(eb64p_mv);
WEAK(eb66_mv);
WEAK(eb66p_mv);
WEAK(eiger_mv);
WEAK(jensen_mv);
WEAK(lx164_mv);
WEAK(marvel_ev7_mv);
WEAK(miata_mv);
WEAK(mikasa_mv);
WEAK(mikasa_primo_mv);
WEAK(monet_mv);
WEAK(nautilus_mv);
WEAK(noname_mv);
WEAK(noritake_mv);
WEAK(noritake_primo_mv);
WEAK(p2k_mv);
WEAK(pc164_mv);
WEAK(privateer_mv);
WEAK(rawhide_mv);
WEAK(ruffian_mv);
WEAK(rx164_mv);
WEAK(sable_mv);
WEAK(sable_gamma_mv);
WEAK(shark_mv);
WEAK(sx164_mv);
WEAK(takara_mv);
WEAK(titan_mv);
WEAK(webbrick_mv);
WEAK(wildfire_mv);
WEAK(xl_mv);
WEAK(xlt_mv);

#undef WEAK

/*
 * I/O resources inherited from PeeCees.  Except for perhaps the
 * turbochannel alphas, everyone has these on some sort of SuperIO chip.
 *
 * ??? If this becomes less standard, move the struct out into the
 * machine vector.
 */

static void __init
reserve_std_resources(void)
{
	static struct resource standard_io_resources[] = {
		{ "rtc", -1, -1 },
        	{ "dma1", 0x00, 0x1f },
        	{ "pic1", 0x20, 0x3f },
        	{ "timer", 0x40, 0x5f },
        	{ "keyboard", 0x60, 0x6f },
        	{ "dma page reg", 0x80, 0x8f },
        	{ "pic2", 0xa0, 0xbf },
        	{ "dma2", 0xc0, 0xdf },
	};

	struct resource *io = &ioport_resource;
	long i;

	if (hose_head) {
		struct pci_controller *hose;
		for (hose = hose_head; hose; hose = hose->next)
			if (hose->index == 0) {
				io = hose->io_space;
				break;
			}
	}

	/* Fix up for the Jensen's queer RTC placement.  */
	standard_io_resources[0].start = RTC_PORT(0);
	standard_io_resources[0].end = RTC_PORT(0) + 0x10;

	for (i = 0; i < N(standard_io_resources); ++i)
		request_resource(io, standard_io_resources+i);
}

#define PFN_UP(x)	(((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
#define PFN_DOWN(x)	((x) >> PAGE_SHIFT)
#define PFN_PHYS(x)	((x) << PAGE_SHIFT)
#define PFN_MAX		PFN_DOWN(0x80000000)
#define for_each_mem_cluster(memdesc, cluster, i)		\
	for ((cluster) = (memdesc)->cluster, (i) = 0;		\
	     (i) < (memdesc)->numclusters; (i)++, (cluster)++)

static unsigned long __init
get_mem_size_limit(char *s)
{
        unsigned long end = 0;
        char *from = s;

        end = simple_strtoul(from, &from, 0);
        if ( *from == 'K' || *from == 'k' ) {
                end = end << 10;
                from++;
        } else if ( *from == 'M' || *from == 'm' ) {
                end = end << 20;
                from++;
        } else if ( *from == 'G' || *from == 'g' ) {
                end = end << 30;
                from++;
        }
        return end >> PAGE_SHIFT; /* Return the PFN of the limit. */
}

#ifdef CONFIG_BLK_DEV_INITRD
void * __init
move_initrd(unsigned long mem_limit)
{
	void *start;
	unsigned long size;

	size = initrd_end - initrd_start;
	start = __alloc_bootmem(size, PAGE_SIZE, 0);
	if (!start || __pa(start) + size > mem_limit) {
		initrd_start = initrd_end = 0;
		return NULL;
	}
	memmove(start, (void *)initrd_start, size);
	initrd_start = (unsigned long)start;
	initrd_end = initrd_start + size;
	printk(KERN_INFO "initrd moved to %p\n", start);
	return start;
}
#endif

#ifndef CONFIG_DISCONTIGMEM
static void __init
setup_memory(void *kernel_end)
{
	struct memclust_struct * cluster;
	struct memdesc_struct * memdesc;
	unsigned long start_kernel_pfn, end_kernel_pfn;
	unsigned long bootmap_size, bootmap_pages, bootmap_start;
	unsigned long start, end;
	int i;

	/* Find free clusters, and init and free the bootmem accordingly.  */
	memdesc = (struct memdesc_struct *)
	  (hwrpb->mddt_offset + (unsigned long) hwrpb);

	for_each_mem_cluster(memdesc, cluster, i) {
		printk("memcluster %d, usage %01lx, start %8lu, end %8lu\n",
		       i, cluster->usage, cluster->start_pfn,
		       cluster->start_pfn + cluster->numpages);

		/* Bit 0 is console/PALcode reserved.  Bit 1 is
		   non-volatile memory -- we might want to mark
		   this for later.  */
		if (cluster->usage & 3)
			continue;

		end = cluster->start_pfn + cluster->numpages;
		if (end > max_low_pfn)
			max_low_pfn = end;
	}

	/*
	 * Except for the NUMA systems (wildfire, marvel) all of the 
	 * Alpha systems we run on support 32GB of memory or less.
	 * Since the NUMA systems introduce large holes in memory addressing,
	 * we can get into a situation where there is not enough contiguous
	 * memory for the memory map. 
	 *
	 * Limit memory to the first 32GB to limit the NUMA systems to 
	 * memory on their first node (wildfire) or 2 (marvel) to avoid 
	 * not being able to produce the memory map. In order to access 
	 * all of the memory on the NUMA systems, build with discontiguous
	 * memory support.
	 *
	 * If the user specified a memory limit, let that memory limit stand.
	 */
	if (!mem_size_limit) 
		mem_size_limit = (32ul * 1024 * 1024 * 1024) >> PAGE_SHIFT;

	if (mem_size_limit && max_low_pfn >= mem_size_limit)
	{
		printk("setup: forcing memory size to %ldK (from %ldK).\n",
		       mem_size_limit << (PAGE_SHIFT - 10),
		       max_low_pfn    << (PAGE_SHIFT - 10));
		max_low_pfn = mem_size_limit;
	}

	/* Find the bounds of kernel memory.  */
	start_kernel_pfn = PFN_DOWN(KERNEL_START_PHYS);
	end_kernel_pfn = PFN_UP(virt_to_phys(kernel_end));
	bootmap_start = -1;

 try_again:
	if (max_low_pfn <= end_kernel_pfn)
		panic("not enough memory to boot");

	/* We need to know how many physically contiguous pages
	   we'll need for the bootmap.  */
	bootmap_pages = bootmem_bootmap_pages(max_low_pfn);

	/* Now find a good region where to allocate the bootmap.  */
	for_each_mem_cluster(memdesc, cluster, i) {
		if (cluster->usage & 3)
			continue;

		start = cluster->start_pfn;
		end = start + cluster->numpages;
		if (start >= max_low_pfn)
			continue;
		if (end > max_low_pfn)
			end = max_low_pfn;
		if (start < start_kernel_pfn) {
			if (end > end_kernel_pfn
			    && end - end_kernel_pfn >= bootmap_pages) {
				bootmap_start = end_kernel_pfn;
				break;
			} else if (end > start_kernel_pfn)
				end = start_kernel_pfn;
		} else if (start < end_kernel_pfn)
			start = end_kernel_pfn;
		if (end - start >= bootmap_pages) {
			bootmap_start = start;
			break;
		}
	}

	if (bootmap_start == -1) {
		max_low_pfn >>= 1;
		goto try_again;
	}

	/* Allocate the bootmap and mark the whole MM as reserved.  */
	bootmap_size = init_bootmem(bootmap_start, max_low_pfn);

	/* Mark the free regions.  */
	for_each_mem_cluster(memdesc, cluster, i) {
		if (cluster->usage & 3)
			continue;

		start = cluster->start_pfn;
		end = cluster->start_pfn + cluster->numpages;
		if (start >= max_low_pfn)
			continue;
		if (end > max_low_pfn)
			end = max_low_pfn;
		if (start < start_kernel_pfn) {
			if (end > end_kernel_pfn) {
				free_bootmem(PFN_PHYS(start),
					     (PFN_PHYS(start_kernel_pfn)
					      - PFN_PHYS(start)));
				printk("freeing pages %ld:%ld\n",
				       start, start_kernel_pfn);
				start = end_kernel_pfn;
			} else if (end > start_kernel_pfn)
				end = start_kernel_pfn;