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