1/*
2 * Definitions and wrapper functions for kernel decompressor
3 *
4 * Copyright IBM Corp. 2010
5 *
6 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7 */
8
9#include <asm/uaccess.h>
10#include <asm/page.h>
11#include <asm/ipl.h>
12#include "sizes.h"
13
14/*
15 * gzip declarations
16 */
17#define STATIC static
18
19#undef memset
20#undef memcpy
21#undef memmove
22#define memmove memmove
23#define memzero(s, n) memset((s), 0, (n))
24
25/* Symbols defined by linker scripts */
26extern char input_data[];
27extern int input_len;
28extern char _text, _end;
29extern char _bss, _ebss;
30
31static void error(char *m);
32
33static unsigned long free_mem_ptr;
34static unsigned long free_mem_end_ptr;
35
36#ifdef CONFIG_HAVE_KERNEL_BZIP2
37#define HEAP_SIZE	0x400000
38#else
39#define HEAP_SIZE	0x10000
40#endif
41
42#ifdef CONFIG_KERNEL_GZIP
43#include "../../../../lib/decompress_inflate.c"
44#endif
45
46#ifdef CONFIG_KERNEL_BZIP2
47#include "../../../../lib/decompress_bunzip2.c"
48#endif
49
50#ifdef CONFIG_KERNEL_LZMA
51#include "../../../../lib/decompress_unlzma.c"
52#endif
53
54#ifdef CONFIG_KERNEL_LZO
55#include "../../../../lib/decompress_unlzo.c"
56#endif
57
58#ifdef CONFIG_KERNEL_XZ
59#include "../../../../lib/decompress_unxz.c"
60#endif
61
62extern _sclp_print_early(const char *);
63
64static int puts(const char *s)
65{
66	_sclp_print_early(s);
67	return 0;
68}
69
70void *memset(void *s, int c, size_t n)
71{
72	char *xs;
73
74	if (c == 0)
75		return __builtin_memset(s, 0, n);
76
77	xs = (char *) s;
78	if (n > 0)
79		do {
80			*xs++ = c;
81		} while (--n > 0);
82	return s;
83}
84
85void *memcpy(void *__dest, __const void *__src, size_t __n)
86{
87	return __builtin_memcpy(__dest, __src, __n);
88}
89
90void *memmove(void *__dest, __const void *__src, size_t __n)
91{
92	char *d;
93	const char *s;
94
95	if (__dest <= __src)
96		return __builtin_memcpy(__dest, __src, __n);
97	d = __dest + __n;
98	s = __src + __n;
99	while (__n--)
100		*--d = *--s;
101	return __dest;
102}
103
104static void error(char *x)
105{
106	unsigned long long psw = 0x000a0000deadbeefULL;
107
108	puts("\n\n");
109	puts(x);
110	puts("\n\n -- System halted");
111
112	asm volatile("lpsw %0" : : "Q" (psw));
113}
114
115/*
116 * Safe guard the ipl parameter block against a memory area that will be
117 * overwritten. The validity check for the ipl parameter block is complex
118 * (see cio_get_iplinfo and ipl_save_parameters) but if the pointer to
119 * the ipl parameter block intersects with the passed memory area we can
120 * safely assume that we can read from that memory. In that case just copy
121 * the memory to IPL_PARMBLOCK_ORIGIN even if there is no ipl parameter
122 * block.
123 */
124static void check_ipl_parmblock(void *start, unsigned long size)
125{
126	void *src, *dst;
127
128	src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
129	if (src + PAGE_SIZE <= start || src >= start + size)
130		return;
131	dst = (void *) IPL_PARMBLOCK_ORIGIN;
132	memmove(dst, src, PAGE_SIZE);
133	S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
134}
135
136unsigned long decompress_kernel(void)
137{
138	unsigned long output_addr;
139	unsigned char *output;
140
141	output_addr = ((unsigned long) &_end + HEAP_SIZE + 4095UL) & -4096UL;
142	check_ipl_parmblock((void *) 0, output_addr + SZ__bss_start);
143	memset(&_bss, 0, &_ebss - &_bss);
144	free_mem_ptr = (unsigned long)&_end;
145	free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;
146	output = (unsigned char *) output_addr;
147
148#ifdef CONFIG_BLK_DEV_INITRD
149	/*
150	 * Move the initrd right behind the end of the decompressed
151	 * kernel image.
152	 */
153	if (INITRD_START && INITRD_SIZE &&
154	    INITRD_START < (unsigned long) output + SZ__bss_start) {
155		check_ipl_parmblock(output + SZ__bss_start,
156				    INITRD_START + INITRD_SIZE);
157		memmove(output + SZ__bss_start,
158			(void *) INITRD_START, INITRD_SIZE);
159		INITRD_START = (unsigned long) output + SZ__bss_start;
160	}
161#endif
162
163	puts("Uncompressing Linux... ");
164	decompress(input_data, input_len, NULL, NULL, output, NULL, error);
165	puts("Ok, booting the kernel.\n");
166	return (unsigned long) output;
167}
168
169