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 #define _LINUX_STRING_H_
  22
  23 #include <linux/compiler.h>     /* for inline */
  24 #include <linux/types.h>        /* for size_t */
  25 #include <linux/stddef.h>       /* for NULL */
  26 #include <linux/linkage.h>
  27 #include <asm/string.h>
  28
  29 #include <asm/unaligned.h>
  30
  31
  32 static void putstr(const char *ptr);
  33 extern void error(char *x);
  34
  35 #include <mach/uncompress.h>
  36
  37 #ifdef CONFIG_DEBUG_ICEDCC
  38
  39 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
  40
  41 static void icedcc_putc(int ch)
  42 {
  43         int status, i = 0x4000000;
  44
  45         do {
  46                 if (--i < 0)
  47                         return;
  48
  49                 asm volatile ("mrc p14, 0, %0, c0, c1, 0" : "=r" (status));
  50         } while (status & (1 << 29));
  51
  52         asm("mcr p14, 0, %0, c0, c5, 0" : : "r" (ch));
  53 }
  54
  55
  56 #elif defined(CONFIG_CPU_XSCALE)
  57
  58 static void icedcc_putc(int ch)
  59 {
  60         int status, i = 0x4000000;
  61
  62         do {
  63                 if (--i < 0)
  64                         return;
  65
  66                 asm volatile ("mrc p14, 0, %0, c14, c0, 0" : "=r" (status));
  67         } while (status & (1 << 28));
  68
  69         asm("mcr p14, 0, %0, c8, c0, 0" : : "r" (ch));
  70 }
  71
  72 #else
  73
  74 static void icedcc_putc(int ch)
  75 {
  76         int status, i = 0x4000000;
  77
  78         do {
  79                 if (--i < 0)
  80                         return;
  81
  82                 asm volatile ("mrc p14, 0, %0, c0, c0, 0" : "=r" (status));
  83         } while (status & 2);
  84
  85         asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
  86 }
  87
  88 #endif
  89
  90 #define putc(ch)        icedcc_putc(ch)
  91 #endif
  92
  93 static void putstr(const char *ptr)
  94 {
  95         char c;
  96
  97         while ((c = *ptr++) != '\0') {
  98                 if (c == '\n')
  99                         putc('\r');
 100                 putc(c);
 101         }
 102
 103         flush();
 104 }
 105
 106
 107 void *memcpy(void *__dest, __const void *__src, size_t __n)
 108 {
 109         int i = 0;
 110         unsigned char *d = (unsigned char *)__dest, *s = (unsigned char *)__src;
 111
 112         for (i = __n >> 3; i > 0; i--) {
 113                 *d++ = *s++;
 114                 *d++ = *s++;
 115                 *d++ = *s++;
 116                 *d++ = *s++;
 117                 *d++ = *s++;
 118                 *d++ = *s++;
 119                 *d++ = *s++;
 120                 *d++ = *s++;
 121         }
 122
 123         if (__n & 1 << 2) {
 124                 *d++ = *s++;
 125                 *d++ = *s++;
 126                 *d++ = *s++;
 127                 *d++ = *s++;
 128         }
 129
 130         if (__n & 1 << 1) {
 131                 *d++ = *s++;
 132                 *d++ = *s++;
 133         }
 134
 135         if (__n & 1)
 136                 *d++ = *s++;
 137
 138         return __dest;
 139 }
 140
 141 /*
 142  * gzip delarations
 143  */
 144 extern char input_data[];
 145 extern char input_data_end[];
 146
 147 unsigned char *output_data;
 148 unsigned long output_ptr;
 149
 150 unsigned long free_mem_ptr;
 151 unsigned long free_mem_end_ptr;
 152
 153 #ifndef arch_error
 154 #define arch_error(x)
 155 #endif
 156
 157 void error(char *x)
 158 {
 159         arch_error(x);
 160
 161         putstr("\n\n");
 162         putstr(x);
 163         putstr("\n\n -- System halted");
 164
 165         while(1);       /* Halt */
 166 }
 167
 168 asmlinkage void __div0(void)
 169 {
 170         error("Attempting division by 0!");
 171 }
 172
 173 extern void do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x));
 174
 175
 176 unsigned long
 177 decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
 178                 unsigned long free_mem_ptr_end_p,
 179                 int arch_id)
 180 {
 181         unsigned char *tmp;
 182
 183         output_data             = (unsigned char *)output_start;
 184         free_mem_ptr            = free_mem_ptr_p;
 185         free_mem_end_ptr        = free_mem_ptr_end_p;
 186         __machine_arch_type     = arch_id;
 187
 188         arch_decomp_setup();
 189
 190         tmp = (unsigned char *) (((unsigned long)input_data_end) - 4);
 191         output_ptr = get_unaligned_le32(tmp);
 192
 193         putstr("Uncompressing Linux...");
 194         do_decompress(input_data, input_data_end - input_data,
 195                         output_data, error);
 196         putstr(" done, booting the kernel.\n");
 197         return output_ptr;
 198 }