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 #define DISABLE_BRANCH_PROFILING
11 
12 #define __NO_FORTIFY
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/libfdt.h>
17 
18 #include <asm/addrspace.h>
19 #include <asm/unaligned.h>
20 #include <asm-generic/vmlinux.lds.h>
21 
22 /*
23  * These two variables specify the free mem region
24  * that can be used for temporary malloc area
25  */
26 unsigned long free_mem_ptr;
27 unsigned long free_mem_end_ptr;
28 
29 /* The linker tells us where the image is. */
30 extern unsigned char __image_begin[], __image_end[];
31 
32 /* debug interfaces  */
33 #ifdef CONFIG_DEBUG_ZBOOT
34 extern void puts(const char *s);
35 extern void puthex(unsigned long long val);
36 #else
37 #define puts(s) do {} while (0)
38 #define puthex(val) do {} while (0)
39 #endif
40 
41 extern char __appended_dtb[];
42 
43 void error(char *x)
44 {
45 	puts("\n\n");
46 	puts(x);
47 	puts("\n\n -- System halted");
48 
49 	while (1)
50 		;	/* Halt */
51 }
52 
53 /* activate the code for pre-boot environment */
54 #define STATIC static
55 
56 #ifdef CONFIG_KERNEL_GZIP
57 #include "../../../../lib/decompress_inflate.c"
58 #endif
59 
60 #ifdef CONFIG_KERNEL_BZIP2
61 #include "../../../../lib/decompress_bunzip2.c"
62 #endif
63 
64 #ifdef CONFIG_KERNEL_LZ4
65 #include "../../../../lib/decompress_unlz4.c"
66 #endif
67 
68 #ifdef CONFIG_KERNEL_LZMA
69 #include "../../../../lib/decompress_unlzma.c"
70 #endif
71 
72 #ifdef CONFIG_KERNEL_LZO
73 #include "../../../../lib/decompress_unlzo.c"
74 #endif
75 
76 #ifdef CONFIG_KERNEL_XZ
77 #include "../../../../lib/decompress_unxz.c"
78 #endif
79 
80 #ifdef CONFIG_KERNEL_ZSTD
81 #include "../../../../lib/decompress_unzstd.c"
82 #endif
83 
84 const unsigned long __stack_chk_guard = 0x000a0dff;
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 	zimage_start = (unsigned long)(__image_begin);
96 	zimage_size = (unsigned long)(__image_end) -
97 	    (unsigned long)(__image_begin);
98 
99 	puts("zimage at:     ");
100 	puthex(zimage_start);
101 	puts(" ");
102 	puthex(zimage_size + zimage_start);
103 	puts("\n");
104 
105 	/* This area are prepared for mallocing when decompressing */
106 	free_mem_ptr = boot_heap_start;
107 	free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;
108 
109 	/* Display standard Linux/MIPS boot prompt */
110 	puts("Uncompressing Linux at load address ");
111 	puthex(VMLINUX_LOAD_ADDRESS_ULL);
112 	puts("\n");
113 
114 	/* Decompress the kernel with according algorithm */
115 	__decompress((char *)zimage_start, zimage_size, 0, 0,
116 		   (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, 0, error);
117 
118 	if (IS_ENABLED(CONFIG_MIPS_RAW_APPENDED_DTB) &&
119 	    fdt_magic((void *)&__appended_dtb) == FDT_MAGIC) {
120 		unsigned int image_size, dtb_size;
121 
122 		dtb_size = fdt_totalsize((void *)&__appended_dtb);
123 
124 		/* last four bytes is always image size in little endian */
125 		image_size = get_unaligned_le32((void *)__image_end - 4);
126 
127 		/* The device tree's address must be properly aligned  */
128 		image_size = ALIGN(image_size, STRUCT_ALIGNMENT);
129 
130 		puts("Copy device tree to address  ");
131 		puthex(VMLINUX_LOAD_ADDRESS_ULL + image_size);
132 		puts("\n");
133 
134 		/* copy dtb to where the booted kernel will expect it */
135 		memcpy((void *)VMLINUX_LOAD_ADDRESS_ULL + image_size,
136 		       __appended_dtb, dtb_size);
137 	}
138 
139 	/* FIXME: should we flush cache here? */
140 	puts("Now, booting the kernel...\n");
141 }
142