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 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/string.h>
15 #include <linux/libfdt.h>
16 
17 #include <asm/addrspace.h>
18 #include <asm/unaligned.h>
19 #include <asm-generic/vmlinux.lds.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 #ifdef CONFIG_KERNEL_ZSTD
80 #include "../../../../lib/decompress_unzstd.c"
81 #endif
82 
83 const unsigned long __stack_chk_guard = 0x000a0dff;
84 
85 void __stack_chk_fail(void)
86 {
87 	error("stack-protector: Kernel stack is corrupted\n");
88 }
89 
90 void decompress_kernel(unsigned long boot_heap_start)
91 {
92 	unsigned long zimage_start, zimage_size;
93 
94 	zimage_start = (unsigned long)(__image_begin);
95 	zimage_size = (unsigned long)(__image_end) -
96 	    (unsigned long)(__image_begin);
97 
98 	puts("zimage at:     ");
99 	puthex(zimage_start);
100 	puts(" ");
101 	puthex(zimage_size + zimage_start);
102 	puts("\n");
103 
104 	/* This area are prepared for mallocing when decompressing */
105 	free_mem_ptr = boot_heap_start;
106 	free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;
107 
108 	/* Display standard Linux/MIPS boot prompt */
109 	puts("Uncompressing Linux at load address ");
110 	puthex(VMLINUX_LOAD_ADDRESS_ULL);
111 	puts("\n");
112 
113 	/* Decompress the kernel with according algorithm */
114 	__decompress((char *)zimage_start, zimage_size, 0, 0,
115 		   (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, 0, error);
116 
117 	if (IS_ENABLED(CONFIG_MIPS_RAW_APPENDED_DTB) &&
118 	    fdt_magic((void *)&__appended_dtb) == FDT_MAGIC) {
119 		unsigned int image_size, dtb_size;
120 
121 		dtb_size = fdt_totalsize((void *)&__appended_dtb);
122 
123 		/* last four bytes is always image size in little endian */
124 		image_size = get_unaligned_le32((void *)__image_end - 4);
125 
126 		/* The device tree's address must be properly aligned  */
127 		image_size = ALIGN(image_size, STRUCT_ALIGNMENT);
128 
129 		puts("Copy device tree to address  ");
130 		puthex(VMLINUX_LOAD_ADDRESS_ULL + image_size);
131 		puts("\n");
132 
133 		/* copy dtb to where the booted kernel will expect it */
134 		memcpy((void *)VMLINUX_LOAD_ADDRESS_ULL + image_size,
135 		       __appended_dtb, dtb_size);
136 	}
137 
138 	/* FIXME: should we flush cache here? */
139 	puts("Now, booting the kernel...\n");
140 }
141