arch/arm/boot/compressed/misc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * misc.c
   4  *
   5  * This is a collection of several routines from gzip-1.0.3
   6  * adapted for Linux.
   7  *
   8  * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
   9  *
  10  * Modified for ARM Linux by Russell King
  11  *
  12  * Nicolas Pitre <nico@visuaide.com>  1999/04/14 :
  13  *  For this code to run directly from Flash, all constant variables must
  14  *  be marked with 'const' and all other variables initialized at run-time
  15  *  only.  This way all non constant variables will end up in the bss segment,
  16  *  which should point to addresses in RAM and cleared to 0 on start.
  17  *  This allows for a much quicker boot time.
  18  */
  19
  20 unsigned int __machine_arch_type;
  21
  22 #include <linux/compiler.h>     /* for inline */
  23 #include <linux/types.h>
  24 #include <linux/linkage.h>
  25
  26 static void putstr(const char *ptr);
  27 extern void error(char *x);
  28
  29 #include CONFIG_UNCOMPRESS_INCLUDE
  30
  31 #ifdef CONFIG_DEBUG_ICEDCC
  32
  33 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
  34
  35 static void icedcc_putc(int ch)
  36 {
  37         int status, i = 0x4000000;
  38
  39         do {
  40                 if (--i < 0)
  41                         return;
  42
  43                 asm volatile ("mrc p14, 0, %0, c0, c1, 0" : "=r" (status));
  44         } while (status & (1 << 29));
  45
  46         asm("mcr p14, 0, %0, c0, c5, 0" : : "r" (ch));
  47 }
  48
  49
  50 #elif defined(CONFIG_CPU_XSCALE)
  51
  52 static void icedcc_putc(int ch)
  53 {
  54         int status, i = 0x4000000;
  55
  56         do {
  57                 if (--i < 0)
  58                         return;
  59
  60                 asm volatile ("mrc p14, 0, %0, c14, c0, 0" : "=r" (status));
  61         } while (status & (1 << 28));
  62
  63         asm("mcr p14, 0, %0, c8, c0, 0" : : "r" (ch));
  64 }
  65
  66 #else
  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, c0, c0, 0" : "=r" (status));
  77         } while (status & 2);
  78
  79         asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
  80 }
  81
  82 #endif
  83
  84 #define putc(ch)        icedcc_putc(ch)
  85 #endif
  86
  87 static void putstr(const char *ptr)
  88 {
  89         char c;
  90
  91         while ((c = *ptr++) != '\0') {
  92                 if (c == '\n')
  93                         putc('\r');
  94                 putc(c);
  95         }
  96
  97         flush();
  98 }
  99
 100 /*
 101  * gzip declarations
 102  */
 103 extern char input_data[];
 104 extern char input_data_end[];
 105
 106 unsigned char *output_data;
 107
 108 unsigned long free_mem_ptr;
 109 unsigned long free_mem_end_ptr;
 110
 111 #ifndef arch_error
 112 #define arch_error(x)
 113 #endif
 114
 115 void error(char *x)
 116 {
 117         arch_error(x);
 118
 119         putstr("\n\n");
 120         putstr(x);
 121         putstr("\n\n -- System halted");
 122
 123         while(1);       /* Halt */
 124 }
 125
 126 asmlinkage void __div0(void)
 127 {
 128         error("Attempting division by 0!");
 129 }
 130
 131 unsigned long __stack_chk_guard;
 132
 133 void __stack_chk_guard_setup(void)
 134 {
 135         __stack_chk_guard = 0x000a0dff;
 136 }
 137
 138 void __stack_chk_fail(void)
 139 {
 140         error("stack-protector: Kernel stack is corrupted\n");
 141 }
 142
 143 extern int do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x));
 144
 145
 146 void
 147 decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
 148                 unsigned long free_mem_ptr_end_p,
 149                 int arch_id)
 150 {
 151         int ret;
 152
 153         __stack_chk_guard_setup();
 154
 155         output_data             = (unsigned char *)output_start;
 156         free_mem_ptr            = free_mem_ptr_p;
 157         free_mem_end_ptr        = free_mem_ptr_end_p;
 158         __machine_arch_type     = arch_id;
 159
 160         arch_decomp_setup();
 161
 162         putstr("Uncompressing Linux...");
 163         ret = do_decompress(input_data, input_data_end - input_data,
 164                             output_data, error);
 165         if (ret)
 166                 error("decompressor returned an error");
 167         else
 168                 putstr(" done, booting the kernel.\n");
 169 }