boot/compressed/decompress.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Copyright 2001 MontaVista Software Inc.
0004  * Author: Matt Porter <mporter@mvista.com>
0005  *
0006  * Copyright (C) 2009 Lemote, Inc.
0007  * Author: Wu Zhangjin <wuzhangjin@gmail.com>
0008  */
0009
0010 #define DISABLE_BRANCH_PROFILING
0011
0012 #include <linux/types.h>
0013 #include <linux/kernel.h>
0014 #include <linux/string.h>
0015 #include <linux/libfdt.h>
0016
0017 #include <asm/addrspace.h>
0018 #include <asm/unaligned.h>
0019 #include <asm-generic/vmlinux.lds.h>
0020
0021 /*
0022  * These two variables specify the free mem region
0023  * that can be used for temporary malloc area
0024  */
0025 unsigned long free_mem_ptr;
0026 unsigned long free_mem_end_ptr;
0027
0028 /* The linker tells us where the image is. */
0029 extern unsigned char __image_begin[], __image_end[];
0030
0031 /* debug interfaces  */
0032 #ifdef CONFIG_DEBUG_ZBOOT
0033 extern void puts(const char *s);
0034 extern void puthex(unsigned long long val);
0035 #else
0036 #define puts(s) do {} while (0)
0037 #define puthex(val) do {} while (0)
0038 #endif
0039
0040 extern char __appended_dtb[];
0041
0042 void error(char *x)
0043 {
0044     puts("\n\n");
0045     puts(x);
0046     puts("\n\n -- System halted");
0047
0048     while (1)
0049         ;   /* Halt */
0050 }
0051
0052 /* activate the code for pre-boot environment */
0053 #define STATIC static
0054
0055 #ifdef CONFIG_KERNEL_GZIP
0056 #include "../../../../lib/decompress_inflate.c"
0057 #endif
0058
0059 #ifdef CONFIG_KERNEL_BZIP2
0060 #include "../../../../lib/decompress_bunzip2.c"
0061 #endif
0062
0063 #ifdef CONFIG_KERNEL_LZ4
0064 #include "../../../../lib/decompress_unlz4.c"
0065 #endif
0066
0067 #ifdef CONFIG_KERNEL_LZMA
0068 #include "../../../../lib/decompress_unlzma.c"
0069 #endif
0070
0071 #ifdef CONFIG_KERNEL_LZO
0072 #include "../../../../lib/decompress_unlzo.c"
0073 #endif
0074
0075 #ifdef CONFIG_KERNEL_XZ
0076 #include "../../../../lib/decompress_unxz.c"
0077 #endif
0078
0079 #ifdef CONFIG_KERNEL_ZSTD
0080 #include "../../../../lib/decompress_unzstd.c"
0081 #endif
0082
0083 const unsigned long __stack_chk_guard = 0x000a0dff;
0084
0085 void __stack_chk_fail(void)
0086 {
0087     error("stack-protector: Kernel stack is corrupted\n");
0088 }
0089
0090 void decompress_kernel(unsigned long boot_heap_start)
0091 {
0092     unsigned long zimage_start, zimage_size;
0093
0094     zimage_start = (unsigned long)(__image_begin);
0095     zimage_size = (unsigned long)(__image_end) -
0096         (unsigned long)(__image_begin);
0097
0098     puts("zimage at:     ");
0099     puthex(zimage_start);
0100     puts(" ");
0101     puthex(zimage_size + zimage_start);
0102     puts("\n");
0103
0104     /* This area are prepared for mallocing when decompressing */
0105     free_mem_ptr = boot_heap_start;
0106     free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;
0107
0108     /* Display standard Linux/MIPS boot prompt */
0109     puts("Uncompressing Linux at load address ");
0110     puthex(VMLINUX_LOAD_ADDRESS_ULL);
0111     puts("\n");
0112
0113     /* Decompress the kernel with according algorithm */
0114     __decompress((char *)zimage_start, zimage_size, 0, 0,
0115            (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, 0, error);
0116
0117     if (IS_ENABLED(CONFIG_MIPS_RAW_APPENDED_DTB) &&
0118         fdt_magic((void *)&__appended_dtb) == FDT_MAGIC) {
0119         unsigned int image_size, dtb_size;
0120
0121         dtb_size = fdt_totalsize((void *)&__appended_dtb);
0122
0123         /* last four bytes is always image size in little endian */
0124         image_size = get_unaligned_le32((void *)__image_end - 4);
0125
0126         /* The device tree's address must be properly aligned  */
0127         image_size = ALIGN(image_size, STRUCT_ALIGNMENT);
0128
0129         puts("Copy device tree to address  ");
0130         puthex(VMLINUX_LOAD_ADDRESS_ULL + image_size);
0131         puts("\n");
0132
0133         /* copy dtb to where the booted kernel will expect it */
0134         memcpy((void *)VMLINUX_LOAD_ADDRESS_ULL + image_size,
0135                __appended_dtb, dtb_size);
0136     }
0137
0138     /* FIXME: should we flush cache here? */
0139     puts("Now, booting the kernel...\n");
0140 }