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_LZ4
 51#include "../../../../lib/decompress_unlz4.c"
 52#endif
 53
 54#ifdef CONFIG_KERNEL_LZMA
 55#include "../../../../lib/decompress_unlzma.c"
 56#endif
 57
 58#ifdef CONFIG_KERNEL_LZO
 59#include "../../../../lib/decompress_unlzo.c"
 60#endif
 61
 62#ifdef CONFIG_KERNEL_XZ
 63#include "../../../../lib/decompress_unxz.c"
 64#endif
 65
 66extern _sclp_print_early(const char *);
 67
 68static int puts(const char *s)
 69{
 70	_sclp_print_early(s);
 71	return 0;
 72}
 73
 74void *memset(void *s, int c, size_t n)
 75{
 76	char *xs;
 77
 78	xs = s;
 79	while (n--)
 80		*xs++ = c;
 81	return s;
 82}
 83
 84void *memcpy(void *dest, const void *src, size_t n)
 85{
 86	const char *s = src;
 87	char *d = dest;
 88
 89	while (n--)
 90		*d++ = *s++;
 91	return dest;
 92}
 93
 94void *memmove(void *dest, const void *src, size_t n)
 95{
 96	const char *s = src;
 97	char *d = dest;
 98
 99	if (d <= s) {
100		while (n--)
101			*d++ = *s++;
102	} else {
103		d += n;
104		s += n;
105		while (n--)
106			*--d = *--s;
107	}
108	return dest;
109}
110
111static void error(char *x)
112{
113	unsigned long long psw = 0x000a0000deadbeefULL;
114
115	puts("\n\n");
116	puts(x);
117	puts("\n\n -- System halted");
118
119	asm volatile("lpsw %0" : : "Q" (psw));
120}
121
122/*
123 * Safe guard the ipl parameter block against a memory area that will be
124 * overwritten. The validity check for the ipl parameter block is complex
125 * (see cio_get_iplinfo and ipl_save_parameters) but if the pointer to
126 * the ipl parameter block intersects with the passed memory area we can
127 * safely assume that we can read from that memory. In that case just copy
128 * the memory to IPL_PARMBLOCK_ORIGIN even if there is no ipl parameter
129 * block.
130 */
131static void check_ipl_parmblock(void *start, unsigned long size)
132{
133	void *src, *dst;
134
135	src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
136	if (src + PAGE_SIZE <= start || src >= start + size)
137		return;
138	dst = (void *) IPL_PARMBLOCK_ORIGIN;
139	memmove(dst, src, PAGE_SIZE);
140	S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
141}
142
143unsigned long decompress_kernel(void)
144{
145	unsigned long output_addr;
146	unsigned char *output;
147
148	output_addr = ((unsigned long) &_end + HEAP_SIZE + 4095UL) & -4096UL;
149	check_ipl_parmblock((void *) 0, output_addr + SZ__bss_start);
150	memset(&_bss, 0, &_ebss - &_bss);
151	free_mem_ptr = (unsigned long)&_end;
152	free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;
153	output = (unsigned char *) output_addr;
154
155#ifdef CONFIG_BLK_DEV_INITRD
156	/*
157	 * Move the initrd right behind the end of the decompressed
158	 * kernel image.
159	 */
160	if (INITRD_START && INITRD_SIZE &&
161	    INITRD_START < (unsigned long) output + SZ__bss_start) {
162		check_ipl_parmblock(output + SZ__bss_start,
163				    INITRD_START + INITRD_SIZE);
164		memmove(output + SZ__bss_start,
165			(void *) INITRD_START, INITRD_SIZE);
166		INITRD_START = (unsigned long) output + SZ__bss_start;
167	}
168#endif
169
170	puts("Uncompressing Linux... ");
171	decompress(input_data, input_len, NULL, NULL, output, NULL, error);
172	puts("Ok, booting the kernel.\n");
173	return (unsigned long) output;
174}
175