arch/mips/boot/compressed/decompress.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2001 MontaVista Software Inc.
   4  * Author: Matt Porter <mporter@mvista.com>
   5  *
   6  * Copyright (C) 2009 Lemote, Inc.
   7  * Author: Wu Zhangjin <wuzhangjin@gmail.com>
   8  */
   9
  10 #include <linux/types.h>
  11 #include <linux/kernel.h>
  12 #include <linux/string.h>
  13 #include <linux/libfdt.h>
  14
  15 #include <asm/addrspace.h>
  16 #include <asm/unaligned.h>
  17
  18 /*
  19  * These two variables specify the free mem region
  20  * that can be used for temporary malloc area
  21  */
  22 unsigned long free_mem_ptr;
  23 unsigned long free_mem_end_ptr;
  24
  25 /* The linker tells us where the image is. */
  26 extern unsigned char __image_begin, __image_end;
  27
  28 /* debug interfaces  */
  29 #ifdef CONFIG_DEBUG_ZBOOT
  30 extern void puts(const char *s);
  31 extern void puthex(unsigned long long val);
  32 #else
  33 #define puts(s) do {} while (0)
  34 #define puthex(val) do {} while (0)
  35 #endif
  36
  37 extern char __appended_dtb[];
  38
  39 void error(char *x)
  40 {
  41         puts("\n\n");
  42         puts(x);
  43         puts("\n\n -- System halted");
  44
  45         while (1)
  46                 ;       /* Halt */
  47 }
  48
  49 /* activate the code for pre-boot environment */
  50 #define STATIC static
  51
  52 #ifdef CONFIG_KERNEL_GZIP
  53 #include "../../../../lib/decompress_inflate.c"
  54 #endif
  55
  56 #ifdef CONFIG_KERNEL_BZIP2
  57 #include "../../../../lib/decompress_bunzip2.c"
  58 #endif
  59
  60 #ifdef CONFIG_KERNEL_LZ4
  61 #include "../../../../lib/decompress_unlz4.c"
  62 #endif
  63
  64 #ifdef CONFIG_KERNEL_LZMA
  65 #include "../../../../lib/decompress_unlzma.c"
  66 #endif
  67
  68 #ifdef CONFIG_KERNEL_LZO
  69 #include "../../../../lib/decompress_unlzo.c"
  70 #endif
  71
  72 #ifdef CONFIG_KERNEL_XZ
  73 #include "../../../../lib/decompress_unxz.c"
  74 #endif
  75
  76 #ifdef CONFIG_KERNEL_ZSTD
  77 #include "../../../../lib/decompress_unzstd.c"
  78 #endif
  79
  80 const unsigned long __stack_chk_guard = 0x000a0dff;
  81
  82 void __stack_chk_fail(void)
  83 {
  84         error("stack-protector: Kernel stack is corrupted\n");
  85 }
  86
  87 void decompress_kernel(unsigned long boot_heap_start)
  88 {
  89         unsigned long zimage_start, zimage_size;
  90
  91         zimage_start = (unsigned long)(&__image_begin);
  92         zimage_size = (unsigned long)(&__image_end) -
  93             (unsigned long)(&__image_begin);
  94
  95         puts("zimage at:     ");
  96         puthex(zimage_start);
  97         puts(" ");
  98         puthex(zimage_size + zimage_start);
  99         puts("\n");
 100
 101         /* This area are prepared for mallocing when decompressing */
 102         free_mem_ptr = boot_heap_start;
 103         free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;
 104
 105         /* Display standard Linux/MIPS boot prompt */
 106         puts("Uncompressing Linux at load address ");
 107         puthex(VMLINUX_LOAD_ADDRESS_ULL);
 108         puts("\n");
 109
 110         /* Decompress the kernel with according algorithm */
 111         __decompress((char *)zimage_start, zimage_size, 0, 0,
 112                    (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, 0, error);
 113
 114         if (IS_ENABLED(CONFIG_MIPS_RAW_APPENDED_DTB) &&
 115             fdt_magic((void *)&__appended_dtb) == FDT_MAGIC) {
 116                 unsigned int image_size, dtb_size;
 117
 118                 dtb_size = fdt_totalsize((void *)&__appended_dtb);
 119
 120                 /* last four bytes is always image size in little endian */
 121                 image_size = get_unaligned_le32((void *)&__image_end - 4);
 122
 123                 /* copy dtb to where the booted kernel will expect it */
 124                 memcpy((void *)VMLINUX_LOAD_ADDRESS_ULL + image_size,
 125                        __appended_dtb, dtb_size);
 126         }
 127
 128         /* FIXME: should we flush cache here? */
 129         puts("Now, booting the kernel...\n");
 130 }