1 // SPDX-License-Identifier: GPL-2.0
3 * Definitions and wrapper functions for kernel decompressor
5 * Copyright IBM Corp. 2010
7 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
10 #include <linux/kernel.h>
11 #include <linux/string.h>
13 #include "decompressor.h"
23 #define memmove memmove
24 #define memzero(s, n) memset((s), 0, (n))
26 /* Symbols defined by linker scripts */
28 extern unsigned char _compressed_start[];
29 extern unsigned char _compressed_end[];
31 #ifdef CONFIG_KERNEL_BZIP2
32 #define BOOT_HEAP_SIZE 0x400000
33 #elif CONFIG_KERNEL_ZSTD
34 #define BOOT_HEAP_SIZE 0x30000
36 #define BOOT_HEAP_SIZE 0x10000
39 static unsigned long free_mem_ptr = (unsigned long) _end;
40 static unsigned long free_mem_end_ptr = (unsigned long) _end + BOOT_HEAP_SIZE;
42 #ifdef CONFIG_KERNEL_GZIP
43 #include "../../../../lib/decompress_inflate.c"
46 #ifdef CONFIG_KERNEL_BZIP2
47 #include "../../../../lib/decompress_bunzip2.c"
50 #ifdef CONFIG_KERNEL_LZ4
51 #include "../../../../lib/decompress_unlz4.c"
54 #ifdef CONFIG_KERNEL_LZMA
55 #include "../../../../lib/decompress_unlzma.c"
58 #ifdef CONFIG_KERNEL_LZO
59 #include "../../../../lib/decompress_unlzo.c"
62 #ifdef CONFIG_KERNEL_XZ
63 #include "../../../../lib/decompress_unxz.c"
66 #ifdef CONFIG_KERNEL_ZSTD
67 #include "../../../../lib/decompress_unzstd.c"
70 #define decompress_offset ALIGN((unsigned long)_end + BOOT_HEAP_SIZE, PAGE_SIZE)
72 unsigned long mem_safe_offset(void)
75 * due to 4MB HEAD_SIZE for bzip2
76 * 'decompress_offset + vmlinux.image_size' could be larger than
77 * kernel at final position + its .bss, so take the larger of two
79 return max(decompress_offset + vmlinux.image_size,
80 vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size);
83 void *decompress_kernel(void)
85 void *output = (void *)decompress_offset;
87 __decompress(_compressed_start, _compressed_end - _compressed_start,
88 NULL, NULL, output, 0, NULL, error);