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