linux/arch/cris/kernel/setup.c
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   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 <linux/of.h>
  23#include <linux/of_fdt.h>
  24#include <linux/of_platform.h>
  25#include <asm/setup.h>
  26#include <arch/system.h>
  27
  28/*
  29 * Setup options
  30 */
  31struct screen_info screen_info;
  32
  33extern int root_mountflags;
  34extern char _etext, _edata, _end;
  35
  36char __initdata cris_command_line[COMMAND_LINE_SIZE] = { 0, };
  37
  38extern const unsigned long text_start, edata; /* set by the linker script */
  39extern unsigned long dram_start, dram_end;
  40
  41extern unsigned long romfs_start, romfs_length, romfs_in_flash; /* from head.S */
  42
  43static struct cpu cpu_devices[NR_CPUS];
  44
  45extern void show_etrax_copyright(void);         /* arch-vX/kernel/setup.c */
  46
  47/* This mainly sets up the memory area, and can be really confusing.
  48 *
  49 * The physical DRAM is virtually mapped into dram_start to dram_end
  50 * (usually c0000000 to c0000000 + DRAM size). The physical address is
  51 * given by the macro __pa().
  52 *
  53 * In this DRAM, the kernel code and data is loaded, in the beginning.
  54 * It really starts at c0004000 to make room for some special pages -
  55 * the start address is text_start. The kernel data ends at _end. After
  56 * this the ROM filesystem is appended (if there is any).
  57 *
  58 * Between this address and dram_end, we have RAM pages usable to the
  59 * boot code and the system.
  60 *
  61 */
  62
  63void __init setup_arch(char **cmdline_p)
  64{
  65        extern void init_etrax_debug(void);
  66        unsigned long bootmap_size;
  67        unsigned long start_pfn, max_pfn;
  68        unsigned long memory_start;
  69
  70#ifdef CONFIG_OF
  71        early_init_dt_scan(__dtb_start);
  72#endif
  73
  74        /* register an initial console printing routine for printk's */
  75
  76        init_etrax_debug();
  77
  78        /* we should really poll for DRAM size! */
  79
  80        high_memory = &dram_end;
  81
  82        if(romfs_in_flash || !romfs_length) {
  83                /* if we have the romfs in flash, or if there is no rom filesystem,
  84                 * our free area starts directly after the BSS
  85                 */
  86                memory_start = (unsigned long) &_end;
  87        } else {
  88                /* otherwise the free area starts after the ROM filesystem */
  89                printk("ROM fs in RAM, size %lu bytes\n", romfs_length);
  90                memory_start = romfs_start + romfs_length;
  91        }
  92
  93        /* process 1's initial memory region is the kernel code/data */
  94
  95        init_mm.start_code = (unsigned long) &text_start;
  96        init_mm.end_code =   (unsigned long) &_etext;
  97        init_mm.end_data =   (unsigned long) &_edata;
  98        init_mm.brk =        (unsigned long) &_end;
  99
 100        /* min_low_pfn points to the start of DRAM, start_pfn points
 101         * to the first DRAM pages after the kernel, and max_low_pfn
 102         * to the end of DRAM.
 103         */
 104
 105        /*
 106         * partially used pages are not usable - thus
 107         * we are rounding upwards:
 108         */
 109
 110        start_pfn = PFN_UP(memory_start);  /* usually c0000000 + kernel + romfs */
 111        max_pfn =   PFN_DOWN((unsigned long)high_memory); /* usually c0000000 + dram size */
 112
 113        /*
 114         * Initialize the boot-time allocator (start, end)
 115         *
 116         * We give it access to all our DRAM, but we could as well just have
 117         * given it a small slice. No point in doing that though, unless we
 118         * have non-contiguous memory and want the boot-stuff to be in, say,
 119         * the smallest area.
 120         *
 121         * It will put a bitmap of the allocated pages in the beginning
 122         * of the range we give it, but it won't mark the bitmaps pages
 123         * as reserved. We have to do that ourselves below.
 124         *
 125         * We need to use init_bootmem_node instead of init_bootmem
 126         * because our map starts at a quite high address (min_low_pfn).
 127         */
 128
 129        max_low_pfn = max_pfn;
 130        min_low_pfn = PAGE_OFFSET >> PAGE_SHIFT;
 131
 132        bootmap_size = init_bootmem_node(NODE_DATA(0), start_pfn,
 133                                         min_low_pfn,
 134                                         max_low_pfn);
 135
 136        /* And free all memory not belonging to the kernel (addr, size) */
 137
 138        free_bootmem(PFN_PHYS(start_pfn), PFN_PHYS(max_pfn - start_pfn));
 139
 140        /*
 141         * Reserve the bootmem bitmap itself as well. We do this in two
 142         * steps (first step was init_bootmem()) because this catches
 143         * the (very unlikely) case of us accidentally initializing the
 144         * bootmem allocator with an invalid RAM area.
 145         *
 146         * Arguments are start, size
 147         */
 148
 149        reserve_bootmem(PFN_PHYS(start_pfn), bootmap_size, BOOTMEM_DEFAULT);
 150
 151        unflatten_and_copy_device_tree();
 152
 153        /* paging_init() sets up the MMU and marks all pages as reserved */
 154
 155        paging_init();
 156
 157        *cmdline_p = cris_command_line;
 158
 159#ifdef CONFIG_ETRAX_CMDLINE
 160        if (!strcmp(cris_command_line, "")) {
 161                strlcpy(cris_command_line, CONFIG_ETRAX_CMDLINE, COMMAND_LINE_SIZE);
 162                cris_command_line[COMMAND_LINE_SIZE - 1] = '\0';
 163        }
 164#endif
 165
 166        /* Save command line for future references. */
 167        memcpy(boot_command_line, cris_command_line, COMMAND_LINE_SIZE);
 168        boot_command_line[COMMAND_LINE_SIZE - 1] = '\0';
 169
 170        /* give credit for the CRIS port */
 171        show_etrax_copyright();
 172
 173        /* Setup utsname */
 174        strcpy(init_utsname()->machine, cris_machine_name);
 175}
 176
 177#ifdef CONFIG_PROC_FS
 178static void *c_start(struct seq_file *m, loff_t *pos)
 179{
 180        return *pos < nr_cpu_ids ? (void *)(int)(*pos + 1) : NULL;
 181}
 182
 183static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 184{
 185        ++*pos;
 186        return c_start(m, pos);
 187}
 188
 189static void c_stop(struct seq_file *m, void *v)
 190{
 191}
 192
 193extern int show_cpuinfo(struct seq_file *m, void *v);
 194
 195const struct seq_operations cpuinfo_op = {
 196        .start = c_start,
 197        .next  = c_next,
 198        .stop  = c_stop,
 199        .show  = show_cpuinfo,
 200};
 201#endif /* CONFIG_PROC_FS */
 202
 203static int __init topology_init(void)
 204{
 205        int i;
 206
 207        for_each_possible_cpu(i) {
 208                 return register_cpu(&cpu_devices[i], i);
 209        }
 210
 211        return 0;
 212}
 213
 214subsys_initcall(topology_init);
 215
 216static int __init cris_of_init(void)
 217{
 218        of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 219        return 0;
 220}
 221core_initcall(cris_of_init);
 222