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 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/libfdt.h>
  18
  19 #include <asm/addrspace.h>
  20
  21 /*
  22  * These two variables specify the free mem region
  23  * that can be used for temporary malloc area
  24  */
  25 unsigned long free_mem_ptr;
  26 unsigned long free_mem_end_ptr;
  27
  28 /* The linker tells us where the image is. */
  29 extern unsigned char __image_begin, __image_end;
  30
  31 /* debug interfaces  */
  32 #ifdef CONFIG_DEBUG_ZBOOT
  33 extern void puts(const char *s);
  34 extern void puthex(unsigned long long val);
  35 #else
  36 #define puts(s) do {} while (0)
  37 #define puthex(val) do {} while (0)
  38 #endif
  39
  40 extern char __appended_dtb[];
  41
  42 void error(char *x)
  43 {
  44         puts("\n\n");
  45         puts(x);
  46         puts("\n\n -- System halted");
  47
  48         while (1)
  49                 ;       /* Halt */
  50 }
  51
  52 /* activate the code for pre-boot environment */
  53 #define STATIC static
  54
  55 #ifdef CONFIG_KERNEL_GZIP
  56 #include "../../../../lib/decompress_inflate.c"
  57 #endif
  58
  59 #ifdef CONFIG_KERNEL_BZIP2
  60 #include "../../../../lib/decompress_bunzip2.c"
  61 #endif
  62
  63 #ifdef CONFIG_KERNEL_LZ4
  64 #include "../../../../lib/decompress_unlz4.c"
  65 #endif
  66
  67 #ifdef CONFIG_KERNEL_LZMA
  68 #include "../../../../lib/decompress_unlzma.c"
  69 #endif
  70
  71 #ifdef CONFIG_KERNEL_LZO
  72 #include "../../../../lib/decompress_unlzo.c"
  73 #endif
  74
  75 #ifdef CONFIG_KERNEL_XZ
  76 #include "../../../../lib/decompress_unxz.c"
  77 #endif
  78
  79 unsigned long __stack_chk_guard;
  80
  81 void __stack_chk_guard_setup(void)
  82 {
  83         __stack_chk_guard = 0x000a0dff;
  84 }
  85
  86 void __stack_chk_fail(void)
  87 {
  88         error("stack-protector: Kernel stack is corrupted\n");
  89 }
  90
  91 void decompress_kernel(unsigned long boot_heap_start)
  92 {
  93         unsigned long zimage_start, zimage_size;
  94
  95         __stack_chk_guard_setup();
  96
  97         zimage_start = (unsigned long)(&__image_begin);
  98         zimage_size = (unsigned long)(&__image_end) -
  99             (unsigned long)(&__image_begin);
 100
 101         puts("zimage at:     ");
 102         puthex(zimage_start);
 103         puts(" ");
 104         puthex(zimage_size + zimage_start);
 105         puts("\n");
 106
 107         /* This area are prepared for mallocing when decompressing */
 108         free_mem_ptr = boot_heap_start;
 109         free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;
 110
 111         /* Display standard Linux/MIPS boot prompt */
 112         puts("Uncompressing Linux at load address ");
 113         puthex(VMLINUX_LOAD_ADDRESS_ULL);
 114         puts("\n");
 115
 116         /* Decompress the kernel with according algorithm */
 117         __decompress((char *)zimage_start, zimage_size, 0, 0,
 118                    (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, 0, error);
 119
 120         if (IS_ENABLED(CONFIG_MIPS_RAW_APPENDED_DTB) &&
 121             fdt_magic((void *)&__appended_dtb) == FDT_MAGIC) {
 122                 unsigned int image_size, dtb_size;
 123
 124                 dtb_size = fdt_totalsize((void *)&__appended_dtb);
 125
 126                 /* last four bytes is always image size in little endian */
 127                 image_size = le32_to_cpup((void *)&__image_end - 4);
 128
 129                 /* copy dtb to where the booted kernel will expect it */
 130                 memcpy((void *)VMLINUX_LOAD_ADDRESS_ULL + image_size,
 131                        __appended_dtb, dtb_size);
 132         }
 133
 134         /* FIXME: should we flush cache here? */
 135         puts("Now, booting the kernel...\n");
 136 }