os/linux-2.6-tag--devboard-R2_10-4/arch/cris/kernel/setup.c

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/*
 *
 *  linux/arch/cris/kernel/setup.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 *  Copyright (c) 2001  Axis Communications AB
 */

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

#include <linux/init.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <asm/pgtable.h>
#include <linux/seq_file.h>
#include <linux/screen_info.h>
#include <linux/utsname.h>
#include <linux/pfn.h>
#include <linux/cpu.h>
#include <asm/setup.h>

/*
 * Setup options
 */
struct screen_info screen_info;

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

char cris_command_line[COMMAND_LINE_SIZE] = { 0, };

extern const unsigned long text_start, edata; /* set by the linker script */
extern unsigned long dram_start, dram_end;

extern unsigned long romfs_start, romfs_length, romfs_in_flash; /* from head.S */

static struct cpu cpu_devices[NR_CPUS];

extern void show_etrax_copyright(void);         /* arch-vX/kernel/setup.c */

/* This mainly sets up the memory area, and can be really confusing.
 *
 * The physical DRAM is virtually mapped into dram_start to dram_end
 * (usually c0000000 to c0000000 + DRAM size). The physical address is
 * given by the macro __pa().
 *
 * In this DRAM, the kernel code and data is loaded, in the beginning.
 * It really starts at c0004000 to make room for some special pages - 
 * the start address is text_start. The kernel data ends at _end. After
 * this the ROM filesystem is appended (if there is any).
 * 
 * Between this address and dram_end, we have RAM pages usable to the
 * boot code and the system.
 *
 */

void __init 
setup_arch(char **cmdline_p)
{
        extern void init_etrax_debug(void);
        unsigned long bootmap_size;
        unsigned long start_pfn, max_pfn;
        unsigned long memory_start;

        /* register an initial console printing routine for printk's */

        init_etrax_debug();

        /* we should really poll for DRAM size! */

        high_memory = &dram_end;

        if(romfs_in_flash || !romfs_length) {
                /* if we have the romfs in flash, or if there is no rom filesystem,
                 * our free area starts directly after the BSS
                 */
                memory_start = (unsigned long) &_end;
        } else {
                /* otherwise the free area starts after the ROM filesystem */
                printk("ROM fs in RAM, size %lu bytes\n", romfs_length);
                memory_start = romfs_start + romfs_length;
        }

        /* process 1's initial memory region is the kernel code/data */

        init_mm.start_code = (unsigned long) &text_start;
        init_mm.end_code =   (unsigned long) &_etext;
        init_mm.end_data =   (unsigned long) &_edata;
        init_mm.brk =        (unsigned long) &_end;

        /* min_low_pfn points to the start of DRAM, start_pfn points
         * to the first DRAM pages after the kernel, and max_low_pfn
         * to the end of DRAM.
         */

        /*
         * partially used pages are not usable - thus
         * we are rounding upwards:
         */

        start_pfn = PFN_UP(memory_start);  /* usually c0000000 + kernel + romfs */
        max_pfn =   PFN_DOWN((unsigned long)high_memory); /* usually c0000000 + dram size */

        /*
         * Initialize the boot-time allocator (start, end)
         *
         * We give it access to all our DRAM, but we could as well just have
         * given it a small slice. No point in doing that though, unless we
         * have non-contiguous memory and want the boot-stuff to be in, say,
         * the smallest area.
         *
         * It will put a bitmap of the allocated pages in the beginning
         * of the range we give it, but it won't mark the bitmaps pages
         * as reserved. We have to do that ourselves below.
         *
         * We need to use init_bootmem_node instead of init_bootmem
         * because our map starts at a quite high address (min_low_pfn).
         */

        max_low_pfn = max_pfn;
        min_low_pfn = PAGE_OFFSET >> PAGE_SHIFT;

        bootmap_size = init_bootmem_node(NODE_DATA(0), start_pfn,
                                         min_low_pfn, 
                                         max_low_pfn);

        /* And free all memory not belonging to the kernel (addr, size) */

        free_bootmem(PFN_PHYS(start_pfn), PFN_PHYS(max_pfn - start_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.
         *
         * Arguments are start, size
         */

        reserve_bootmem(PFN_PHYS(start_pfn), bootmap_size);

        /* paging_init() sets up the MMU and marks all pages as reserved */

        paging_init();

        /* look for command line in memory */
        //#define CMDLINE_MAGIC 0x87109563
        #define CMDLINE_MAGIC   0x63951087
        unsigned char *cmdline_ram = (unsigned char *)0xC0004000;
        unsigned long *ul_cmdline_ram = (unsigned long *)0xC0004000;
//      printk("____________________________________________________________\n");
//      printk("==>> stamp in memory is: 0x%02X, 0x%02X, 0x%02X, 0x%02X\n", cmdline_ram[0], cmdline_ram[1], cmdline_ram[2], cmdline_ram[3]);
        if(ul_cmdline_ram[0] == CMDLINE_MAGIC) {
                printk("command line found: \"%s\"\n", &cmdline_ram[4]);
                strcpy(cris_command_line, &cmdline_ram[4]);
        } else {
//              printk("magic is: 0x%08X; stamp in memory is: 0x%08X\n", CMDLINE_MAGIC, ul_cmdline_ram[0]);
        }
        cmdline_ram[0] = 0x00;
        cmdline_ram[1] = 0x00;
        cmdline_ram[2] = 0x00;
        cmdline_ram[3] = 0x00;

        *cmdline_p = cris_command_line;

#ifdef CONFIG_ETRAX_CMDLINE
        if (!strcmp(cris_command_line, "")) {
                strlcpy(cris_command_line, CONFIG_ETRAX_CMDLINE, COMMAND_LINE_SIZE);
                cris_command_line[COMMAND_LINE_SIZE - 1] = '\0';
        }
#endif

        /* Save command line for future references. */
        memcpy(saved_command_line, cris_command_line, COMMAND_LINE_SIZE);
        saved_command_line[COMMAND_LINE_SIZE - 1] = '\0';

        /* give credit for the CRIS port */
        show_etrax_copyright();

        /* Setup utsname */
        strcpy(init_utsname()->machine, cris_machine_name);
}

static void *c_start(struct seq_file *m, loff_t *pos)
{
        return *pos < NR_CPUS ? (void *)(int)(*pos + 1): NULL;
}

static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
        ++*pos;
        return c_start(m, pos);
}

static void c_stop(struct seq_file *m, void *v)
{
}

extern int show_cpuinfo(struct seq_file *m, void *v);

struct seq_operations cpuinfo_op = {
        .start = c_start,
        .next  = c_next,
        .stop  = c_stop,
        .show  = show_cpuinfo,
};

static int __init topology_init(void)
{
        int i;
        
        for_each_possible_cpu(i) {
                 return register_cpu(&cpu_devices[i], i);
        }
}

subsys_initcall(topology_init);

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