arch/mips/boot/compressed/decompress.c

   1 /*
   2  * Copyright 2001 MontaVista Software Inc.
   3  * Author: Matt Porter <mporter@mvista.com>
   4  *
   5  * Copyright (C) 2009 Lemote, Inc.
   6  * Author: Wu Zhangjin <wuzhangjin@gmail.com>
   7  *
   8  * This program is free software; you can redistribute  it and/or modify it
   9  * under  the terms of  the GNU General  Public License as published by the
  10  * Free Software Foundation;  either version 2 of the  License, or (at your
  11  * option) any later version.
  12  */
  13
  14 #define DISABLE_BRANCH_PROFILING
  15
  16 #include <linux/types.h>
  17 #include <linux/kernel.h>
  18 #include <linux/string.h>
  19 #include <linux/libfdt.h>
  20
  21 #include <asm/addrspace.h>
  22 #include <asm/unaligned.h>
  23
  24 /*
  25  * These two variables specify the free mem region
  26  * that can be used for temporary malloc area
  27  */
  28 unsigned long free_mem_ptr;
  29 unsigned long free_mem_end_ptr;
  30
  31 /* The linker tells us where the image is. */
  32 extern unsigned char __image_begin, __image_end;
  33
  34 /* debug interfaces  */
  35 #ifdef CONFIG_DEBUG_ZBOOT
  36 extern void puts(const char *s);
  37 extern void puthex(unsigned long long val);
  38 #else
  39 #define puts(s) do {} while (0)
  40 #define puthex(val) do {} while (0)
  41 #endif
  42
  43 extern char __appended_dtb[];
  44
  45 void error(char *x)
  46 {
  47         puts("\n\n");
  48         puts(x);
  49         puts("\n\n -- System halted");
  50
  51         while (1)
  52                 ;       /* Halt */
  53 }
  54
  55 /* activate the code for pre-boot environment */
  56 #define STATIC static
  57
  58 #ifdef CONFIG_KERNEL_GZIP
  59 #include "../../../../lib/decompress_inflate.c"
  60 #endif
  61
  62 #ifdef CONFIG_KERNEL_BZIP2
  63 #include "../../../../lib/decompress_bunzip2.c"
  64 #endif
  65
  66 #ifdef CONFIG_KERNEL_LZ4
  67 #include "../../../../lib/decompress_unlz4.c"
  68 #endif
  69
  70 #ifdef CONFIG_KERNEL_LZMA
  71 #include "../../../../lib/decompress_unlzma.c"
  72 #endif
  73
  74 #ifdef CONFIG_KERNEL_LZO
  75 #include "../../../../lib/decompress_unlzo.c"
  76 #endif
  77
  78 #ifdef CONFIG_KERNEL_XZ
  79 #include "../../../../lib/decompress_unxz.c"
  80 #endif
  81
  82 unsigned long __stack_chk_guard;
  83
  84 void __stack_chk_guard_setup(void)
  85 {
  86         __stack_chk_guard = 0x000a0dff;
  87 }
  88
  89 void __stack_chk_fail(void)
  90 {
  91         error("stack-protector: Kernel stack is corrupted\n");
  92 }
  93
  94 void decompress_kernel(unsigned long boot_heap_start)
  95 {
  96         unsigned long zimage_start, zimage_size;
  97
  98         __stack_chk_guard_setup();
  99
 100         zimage_start = (unsigned long)(&__image_begin);
 101         zimage_size = (unsigned long)(&__image_end) -
 102             (unsigned long)(&__image_begin);
 103
 104         puts("zimage at:     ");
 105         puthex(zimage_start);
 106         puts(" ");
 107         puthex(zimage_size + zimage_start);
 108         puts("\n");
 109
 110         /* This area are prepared for mallocing when decompressing */
 111         free_mem_ptr = boot_heap_start;
 112         free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;
 113
 114         /* Display standard Linux/MIPS boot prompt */
 115         puts("Uncompressing Linux at load address ");
 116         puthex(VMLINUX_LOAD_ADDRESS_ULL);
 117         puts("\n");
 118
 119         /* Decompress the kernel with according algorithm */
 120         __decompress((char *)zimage_start, zimage_size, 0, 0,
 121                    (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, 0, error);
 122
 123         if (IS_ENABLED(CONFIG_MIPS_RAW_APPENDED_DTB) &&
 124             fdt_magic((void *)&__appended_dtb) == FDT_MAGIC) {
 125                 unsigned int image_size, dtb_size;
 126
 127                 dtb_size = fdt_totalsize((void *)&__appended_dtb);
 128
 129                 /* last four bytes is always image size in little endian */
 130                 image_size = get_unaligned_le32((void *)&__image_end - 4);
 131
 132                 /* copy dtb to where the booted kernel will expect it */
 133                 memcpy((void *)VMLINUX_LOAD_ADDRESS_ULL + image_size,
 134                        __appended_dtb, dtb_size);
 135         }
 136
 137         /* FIXME: should we flush cache here? */
 138         puts("Now, booting the kernel...\n");
 139 }