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 #ifdef CONFIG_CPU_V6
  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 #elif defined(CONFIG_CPU_V7)
  56
  57 static void icedcc_putc(int ch)
  58 {
  59         asm(
  60         "wait:  mrc     p14, 0, pc, c0, c1, 0                   \n\
  61                 bcs     wait                                    \n\
  62                 mcr     p14, 0, %0, c0, c5, 0                   "
  63         : : "r" (ch));
  64 }
  65
  66 #elif defined(CONFIG_CPU_XSCALE)
  67
  68 static void icedcc_putc(int ch)
  69 {
  70         int status, i = 0x4000000;
  71
  72         do {
  73                 if (--i < 0)
  74                         return;
  75
  76                 asm volatile ("mrc p14, 0, %0, c14, c0, 0" : "=r" (status));
  77         } while (status & (1 << 28));
  78
  79         asm("mcr p14, 0, %0, c8, c0, 0" : : "r" (ch));
  80 }
  81
  82 #else
  83
  84 static void icedcc_putc(int ch)
  85 {
  86         int status, i = 0x4000000;
  87
  88         do {
  89                 if (--i < 0)
  90                         return;
  91
  92                 asm volatile ("mrc p14, 0, %0, c0, c0, 0" : "=r" (status));
  93         } while (status & 2);
  94
  95         asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
  96 }
  97
  98 #endif
  99
 100 #define putc(ch)        icedcc_putc(ch)
 101 #endif
 102
 103 static void putstr(const char *ptr)
 104 {
 105         char c;
 106
 107         while ((c = *ptr++) != '\0') {
 108                 if (c == '\n')
 109                         putc('\r');
 110                 putc(c);
 111         }
 112
 113         flush();
 114 }
 115
 116
 117 void *memcpy(void *__dest, __const void *__src, size_t __n)
 118 {
 119         int i = 0;
 120         unsigned char *d = (unsigned char *)__dest, *s = (unsigned char *)__src;
 121
 122         for (i = __n >> 3; i > 0; i--) {
 123                 *d++ = *s++;
 124                 *d++ = *s++;
 125                 *d++ = *s++;
 126                 *d++ = *s++;
 127                 *d++ = *s++;
 128                 *d++ = *s++;
 129                 *d++ = *s++;
 130                 *d++ = *s++;
 131         }
 132
 133         if (__n & 1 << 2) {
 134                 *d++ = *s++;
 135                 *d++ = *s++;
 136                 *d++ = *s++;
 137                 *d++ = *s++;
 138         }
 139
 140         if (__n & 1 << 1) {
 141                 *d++ = *s++;
 142                 *d++ = *s++;
 143         }
 144
 145         if (__n & 1)
 146                 *d++ = *s++;
 147
 148         return __dest;
 149 }
 150
 151 /*
 152  * gzip delarations
 153  */
 154 extern char input_data[];
 155 extern char input_data_end[];
 156
 157 unsigned char *output_data;
 158 unsigned long output_ptr;
 159
 160 unsigned long free_mem_ptr;
 161 unsigned long free_mem_end_ptr;
 162
 163 #ifndef arch_error
 164 #define arch_error(x)
 165 #endif
 166
 167 void error(char *x)
 168 {
 169         arch_error(x);
 170
 171         putstr("\n\n");
 172         putstr(x);
 173         putstr("\n\n -- System halted");
 174
 175         while(1);       /* Halt */
 176 }
 177
 178 asmlinkage void __div0(void)
 179 {
 180         error("Attempting division by 0!");
 181 }
 182
 183 extern void do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x));
 184
 185
 186 unsigned long
 187 decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
 188                 unsigned long free_mem_ptr_end_p,
 189                 int arch_id)
 190 {
 191         unsigned char *tmp;
 192
 193         output_data             = (unsigned char *)output_start;
 194         free_mem_ptr            = free_mem_ptr_p;
 195         free_mem_end_ptr        = free_mem_ptr_end_p;
 196         __machine_arch_type     = arch_id;
 197
 198         arch_decomp_setup();
 199
 200         tmp = (unsigned char *) (((unsigned long)input_data_end) - 4);
 201         output_ptr = get_unaligned_le32(tmp);
 202
 203         putstr("Uncompressing Linux...");
 204         do_decompress(input_data, input_data_end - input_data,
 205                         output_data, error);
 206         putstr(" done, booting the kernel.\n");
 207         return output_ptr;
 208 }