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