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