arch/arm/boot/compressed/misc.c

   1 /*
   2  * misc.c
   3  *
   4  * This is a collection of several routines from gzip-1.0.3
   5  * adapted for Linux.
   6  *
   7  * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
   8  *
   9  * Modified for ARM Linux by Russell King
  10  *
  11  * Nicolas Pitre <nico@visuaide.com>  1999/04/14 :
  12  *  For this code to run directly from Flash, all constant variables must
  13  *  be marked with 'const' and all other variables initialized at run-time
  14  *  only.  This way all non constant variables will end up in the bss segment,
  15  *  which should point to addresses in RAM and cleared to 0 on start.
  16  *  This allows for a much quicker boot time.
  17  */
  18
  19 unsigned int __machine_arch_type;
  20
  21 #include <linux/compiler.h>     /* for inline */
  22 #include <linux/types.h>
  23 #include <linux/linkage.h>
  24
  25 static void putstr(const char *ptr);
  26 extern void error(char *x);
  27
  28 #include CONFIG_UNCOMPRESS_INCLUDE
  29
  30 #ifdef CONFIG_DEBUG_ICEDCC
  31
  32 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
  33
  34 static void icedcc_putc(int ch)
  35 {
  36         int status, i = 0x4000000;
  37
  38         do {
  39                 if (--i < 0)
  40                         return;
  41
  42                 asm volatile ("mrc p14, 0, %0, c0, c1, 0" : "=r" (status));
  43         } while (status & (1 << 29));
  44
  45         asm("mcr p14, 0, %0, c0, c5, 0" : : "r" (ch));
  46 }
  47
  48
  49 #elif defined(CONFIG_CPU_XSCALE)
  50
  51 static void icedcc_putc(int ch)
  52 {
  53         int status, i = 0x4000000;
  54
  55         do {
  56                 if (--i < 0)
  57                         return;
  58
  59                 asm volatile ("mrc p14, 0, %0, c14, c0, 0" : "=r" (status));
  60         } while (status & (1 << 28));
  61
  62         asm("mcr p14, 0, %0, c8, c0, 0" : : "r" (ch));
  63 }
  64
  65 #else
  66
  67 static void icedcc_putc(int ch)
  68 {
  69         int status, i = 0x4000000;
  70
  71         do {
  72                 if (--i < 0)
  73                         return;
  74
  75                 asm volatile ("mrc p14, 0, %0, c0, c0, 0" : "=r" (status));
  76         } while (status & 2);
  77
  78         asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
  79 }
  80
  81 #endif
  82
  83 #define putc(ch)        icedcc_putc(ch)
  84 #endif
  85
  86 static void putstr(const char *ptr)
  87 {
  88         char c;
  89
  90         while ((c = *ptr++) != '\0') {
  91                 if (c == '\n')
  92                         putc('\r');
  93                 putc(c);
  94         }
  95
  96         flush();
  97 }
  98
  99 /*
 100  * gzip declarations
 101  */
 102 extern char input_data[];
 103 extern char input_data_end[];
 104
 105 unsigned char *output_data;
 106
 107 unsigned long free_mem_ptr;
 108 unsigned long free_mem_end_ptr;
 109
 110 #ifndef arch_error
 111 #define arch_error(x)
 112 #endif
 113
 114 void error(char *x)
 115 {
 116         arch_error(x);
 117
 118         putstr("\n\n");
 119         putstr(x);
 120         putstr("\n\n -- System halted");
 121
 122         while(1);       /* Halt */
 123 }
 124
 125 asmlinkage void __div0(void)
 126 {
 127         error("Attempting division by 0!");
 128 }
 129
 130 unsigned long __stack_chk_guard;
 131
 132 void __stack_chk_guard_setup(void)
 133 {
 134         __stack_chk_guard = 0x000a0dff;
 135 }
 136
 137 void __stack_chk_fail(void)
 138 {
 139         error("stack-protector: Kernel stack is corrupted\n");
 140 }
 141
 142 extern int do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x));
 143
 144
 145 void
 146 decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
 147                 unsigned long free_mem_ptr_end_p,
 148                 int arch_id)
 149 {
 150         int ret;
 151
 152         __stack_chk_guard_setup();
 153
 154         output_data             = (unsigned char *)output_start;
 155         free_mem_ptr            = free_mem_ptr_p;
 156         free_mem_end_ptr        = free_mem_ptr_end_p;
 157         __machine_arch_type     = arch_id;
 158
 159         arch_decomp_setup();
 160
 161         putstr("Uncompressing Linux...");
 162         ret = do_decompress(input_data, input_data_end - input_data,
 163                             output_data, error);
 164         if (ret)
 165                 error("decompressor returned an error");
 166         else
 167                 putstr(" done, booting the kernel.\n");
 168 }