LXR linux/arch/cris/kernel/setup.c

   1/*
   2 *
   3 *  linux/arch/cris/kernel/setup.c
   4 *
   5 *  Copyright (C) 1995  Linus Torvalds
   6 *  Copyright (c) 2001  Axis Communications AB
   7 */
   8
   9/*
  10 * This file handles the architecture-dependent parts of initialization
  11 */
  12
  13#include <linux/init.h>
  14#include <linux/mm.h>
  15#include <linux/bootmem.h>
  16#include <asm/pgtable.h>
  17#include <linux/seq_file.h>
  18#include <linux/screen_info.h>
  19#include <linux/utsname.h>
  20#include <linux/pfn.h>
  21#include <linux/cpu.h>
  22#include <asm/setup.h>
  23#include <arch/system.h>
  24
  25/*
  26 * Setup options
  27 */
  28struct screen_info screen_info;
  29
  30extern int root_mountflags;
  31extern char _etext, _edata, _end;
  32
  33char __initdata cris_command_line[COMMAND_LINE_SIZE] = { 0, };
  34
  35extern const unsigned long text_start, edata; /* set by the linker script */
  36extern unsigned long dram_start, dram_end;
  37
  38extern unsigned long romfs_start, romfs_length, romfs_in_flash; /* from head.S */
  39
  40static struct cpu cpu_devices[NR_CPUS];
  41
  42extern void show_etrax_copyright(void);         /* arch-vX/kernel/setup.c */
  43
  44/* This mainly sets up the memory area, and can be really confusing.
  45 *
  46 * The physical DRAM is virtually mapped into dram_start to dram_end
  47 * (usually c0000000 to c0000000 + DRAM size). The physical address is
  48 * given by the macro __pa().
  49 *
  50 * In this DRAM, the kernel code and data is loaded, in the beginning.
  51 * It really starts at c0004000 to make room for some special pages -
  52 * the start address is text_start. The kernel data ends at _end. After
  53 * this the ROM filesystem is appended (if there is any).
  54 *
  55 * Between this address and dram_end, we have RAM pages usable to the
  56 * boot code and the system.
  57 *
  58 */
  59
  60void __init setup_arch(char **cmdline_p)
  61{
  62        extern void init_etrax_debug(void);
  63        unsigned long bootmap_size;
  64        unsigned long start_pfn, max_pfn;
  65        unsigned long memory_start;
  66
  67        /* register an initial console printing routine for printk's */
  68
  69        init_etrax_debug();
  70
  71        /* we should really poll for DRAM size! */
  72
  73        high_memory = &dram_end;
  74
  75        if(romfs_in_flash || !romfs_length) {
  76                /* if we have the romfs in flash, or if there is no rom filesystem,
  77                 * our free area starts directly after the BSS
  78                 */
  79                memory_start = (unsigned long) &_end;
  80        } else {
  81                /* otherwise the free area starts after the ROM filesystem */
  82                printk("ROM fs in RAM, size %lu bytes\n", romfs_length);
  83                memory_start = romfs_start + romfs_length;
  84        }
  85
  86        /* process 1's initial memory region is the kernel code/data */
  87
  88        init_mm.start_code = (unsigned long) &text_start;
  89        init_mm.end_code =   (unsigned long) &_etext;
  90        init_mm.end_data =   (unsigned long) &_edata;
  91        init_mm.brk =        (unsigned long) &_end;
  92
  93        /* min_low_pfn points to the start of DRAM, start_pfn points
  94         * to the first DRAM pages after the kernel, and max_low_pfn
  95         * to the end of DRAM.
  96         */
  97
  98        /*
  99         * partially used pages are not usable - thus
 100         * we are rounding upwards:
 101         */
 102
 103        start_pfn = PFN_UP(memory_start);  /* usually c0000000 + kernel + romfs */
 104        max_pfn =   PFN_DOWN((unsigned long)high_memory); /* usually c0000000 + dram size */
 105
 106        /*
 107         * Initialize the boot-time allocator (start, end)
 108         *
 109         * We give it access to all our DRAM, but we could as well just have
 110         * given it a small slice. No point in doing that though, unless we
 111         * have non-contiguous memory and want the boot-stuff to be in, say,
 112         * the smallest area.
 113         *
 114         * It will put a bitmap of the allocated pages in the beginning
 115         * of the range we give it, but it won't mark the bitmaps pages
 116         * as reserved. We have to do that ourselves below.
 117         *
 118         * We need to use init_bootmem_node instead of init_bootmem
 119         * because our map starts at a quite high address (min_low_pfn).
 120         */
 121
 122        max_low_pfn = max_pfn;
 123        min_low_pfn = PAGE_OFFSET >> PAGE_SHIFT;
 124
 125        bootmap_size = init_bootmem_node(NODE_DATA(0), start_pfn,
 126                                         min_low_pfn,
 127                                         max_low_pfn);
 128
 129        /* And free all memory not belonging to the kernel (addr, size) */
 130
 131        free_bootmem(PFN_PHYS(start_pfn), PFN_PHYS(max_pfn - start_pfn));
 132
 133        /*
 134         * Reserve the bootmem bitmap itself as well. We do this in two
 135         * steps (first step was init_bootmem()) because this catches
 136         * the (very unlikely) case of us accidentally initializing the
 137         * bootmem allocator with an invalid RAM area.
 138         *
 139         * Arguments are start, size
 140         */
 141
 142        reserve_bootmem(PFN_PHYS(start_pfn), bootmap_size, BOOTMEM_DEFAULT);
 143
 144        /* paging_init() sets up the MMU and marks all pages as reserved */
 145
 146        paging_init();
 147
 148        *cmdline_p = cris_command_line;
 149
 150#ifdef CONFIG_ETRAX_CMDLINE
 151        if (!strcmp(cris_command_line, "")) {
 152                strlcpy(cris_command_line, CONFIG_ETRAX_CMDLINE, COMMAND_LINE_SIZE);
 153                cris_command_line[COMMAND_LINE_SIZE - 1] = '\0';
 154        }
 155#endif
 156
 157        /* Save command line for future references. */
 158        memcpy(boot_command_line, cris_command_line, COMMAND_LINE_SIZE);
 159        boot_command_line[COMMAND_LINE_SIZE - 1] = '\0';
 160
 161        /* give credit for the CRIS port */
 162        show_etrax_copyright();
 163
 164        /* Setup utsname */
 165        strcpy(init_utsname()->machine, cris_machine_name);
 166}
 167
 168static void *c_start(struct seq_file *m, loff_t *pos)
 169{
 170        return *pos < nr_cpu_ids ? (void *)(int)(*pos + 1) : NULL;
 171}
 172
 173static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 174{
 175        ++*pos;
 176        return c_start(m, pos);
 177}
 178
 179static void c_stop(struct seq_file *m, void *v)
 180{
 181}
 182
 183extern int show_cpuinfo(struct seq_file *m, void *v);
 184
 185const struct seq_operations cpuinfo_op = {
 186        .start = c_start,
 187        .next  = c_next,
 188        .stop  = c_stop,
 189        .show  = show_cpuinfo,
 190};
 191
 192static int __init topology_init(void)
 193{
 194        int i;
 195
 196        for_each_possible_cpu(i) {
 197                 return register_cpu(&cpu_devices[i], i);
 198        }
 199
 200        return 0;
 201}
 202
 203subsys_initcall(topology_init);
 204
 205