xref: /openbmc/linux/arch/s390/boot/decompressor.c (revision 55eb9a6c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Definitions and wrapper functions for kernel decompressor
4  *
5  * Copyright IBM Corp. 2010
6  *
7  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/string.h>
12 #include <asm/page.h>
13 #include "decompressor.h"
14 
15 /*
16  * gzip declarations
17  */
18 #define STATIC static
19 
20 #undef memset
21 #undef memcpy
22 #undef memmove
23 #define memmove memmove
24 #define memzero(s, n) memset((s), 0, (n))
25 
26 #ifdef CONFIG_KERNEL_BZIP2
27 #define BOOT_HEAP_SIZE	0x400000
28 #elif CONFIG_KERNEL_ZSTD
29 #define BOOT_HEAP_SIZE	0x30000
30 #else
31 #define BOOT_HEAP_SIZE	0x10000
32 #endif
33 
34 static unsigned long free_mem_ptr = (unsigned long) _end;
35 static unsigned long free_mem_end_ptr = (unsigned long) _end + BOOT_HEAP_SIZE;
36 
37 #ifdef CONFIG_KERNEL_GZIP
38 #include "../../../../lib/decompress_inflate.c"
39 #endif
40 
41 #ifdef CONFIG_KERNEL_BZIP2
42 #include "../../../../lib/decompress_bunzip2.c"
43 #endif
44 
45 #ifdef CONFIG_KERNEL_LZ4
46 #include "../../../../lib/decompress_unlz4.c"
47 #endif
48 
49 #ifdef CONFIG_KERNEL_LZMA
50 #include "../../../../lib/decompress_unlzma.c"
51 #endif
52 
53 #ifdef CONFIG_KERNEL_LZO
54 #include "../../../../lib/decompress_unlzo.c"
55 #endif
56 
57 #ifdef CONFIG_KERNEL_XZ
58 #include "../../../../lib/decompress_unxz.c"
59 #endif
60 
61 #ifdef CONFIG_KERNEL_ZSTD
62 #include "../../../../lib/decompress_unzstd.c"
63 #endif
64 
65 #define decompress_offset ALIGN((unsigned long)_end + BOOT_HEAP_SIZE, PAGE_SIZE)
66 
67 unsigned long mem_safe_offset(void)
68 {
69 	/*
70 	 * due to 4MB HEAD_SIZE for bzip2
71 	 * 'decompress_offset + vmlinux.image_size' could be larger than
72 	 * kernel at final position + its .bss, so take the larger of two
73 	 */
74 	return max(decompress_offset + vmlinux.image_size,
75 		   vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size);
76 }
77 
78 void *decompress_kernel(void)
79 {
80 	void *output = (void *)decompress_offset;
81 
82 	__decompress(_compressed_start, _compressed_end - _compressed_start,
83 		     NULL, NULL, output, 0, NULL, error);
84 	return output;
85 }
86