[deliverable/linux.git] / arch / x86 / boot / compressed / misc.c

/*
 * misc.c
 *
 * This is a collection of several routines from gzip-1.0.3
 * adapted for Linux.
 *
 * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
 * puts by Nick Holloway 1993, better puts by Martin Mares 1995
 * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
 */

#include "misc.h"

/* WARNING!!
 * This code is compiled with -fPIC and it is relocated dynamically
 * at run time, but no relocation processing is performed.
 * This means that it is not safe to place pointers in static structures.
 */

/*
 * Getting to provable safe in place decompression is hard.
 * Worst case behaviours need to be analyzed.
 * Background information:
 *
 * The file layout is:
 *    magic[2]
 *    method[1]
 *    flags[1]
 *    timestamp[4]
 *    extraflags[1]
 *    os[1]
 *    compressed data blocks[N]
 *    crc[4] orig_len[4]
 *
 * resulting in 18 bytes of non compressed data overhead.
 *
 * Files divided into blocks
 * 1 bit (last block flag)
 * 2 bits (block type)
 *
 * 1 block occurs every 32K -1 bytes or when there 50% compression
 * has been achieved. The smallest block type encoding is always used.
 *
 * stored:
 *    32 bits length in bytes.
 *
 * fixed:
 *    magic fixed tree.
 *    symbols.
 *
 * dynamic:
 *    dynamic tree encoding.
 *    symbols.
 *
 *
 * The buffer for decompression in place is the length of the
 * uncompressed data, plus a small amount extra to keep the algorithm safe.
 * The compressed data is placed at the end of the buffer.  The output
 * pointer is placed at the start of the buffer and the input pointer
 * is placed where the compressed data starts.  Problems will occur
 * when the output pointer overruns the input pointer.
 *
 * The output pointer can only overrun the input pointer if the input
 * pointer is moving faster than the output pointer.  A condition only
 * triggered by data whose compressed form is larger than the uncompressed
 * form.
 *
 * The worst case at the block level is a growth of the compressed data
 * of 5 bytes per 32767 bytes.
 *
 * The worst case internal to a compressed block is very hard to figure.
 * The worst case can at least be boundined by having one bit that represents
 * 32764 bytes and then all of the rest of the bytes representing the very
 * very last byte.
 *
 * All of which is enough to compute an amount of extra data that is required
 * to be safe.  To avoid problems at the block level allocating 5 extra bytes
 * per 32767 bytes of data is sufficient.  To avoind problems internal to a
 * block adding an extra 32767 bytes (the worst case uncompressed block size)
 * is sufficient, to ensure that in the worst case the decompressed data for
 * block will stop the byte before the compressed data for a block begins.
 * To avoid problems with the compressed data's meta information an extra 18
 * bytes are needed.  Leading to the formula:
 *
 * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
 *
 * Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
 * Adding 32768 instead of 32767 just makes for round numbers.
 * Adding the decompressor_size is necessary as it musht live after all
 * of the data as well.  Last I measured the decompressor is about 14K.
 * 10K of actual data and 4K of bss.
 *
 */

/*
 * gzip declarations
 */
#define STATIC		static

#undef memset
#undef memcpy
#define memzero(s, n)	memset((s), 0, (n))


static void error(char *m);

/*
 * This is set up by the setup-routine at boot-time
 */
struct boot_params *real_mode;		/* Pointer to real-mode data */
static int quiet;
static int debug;

void *memset(void *s, int c, size_t n);
void *memcpy(void *dest, const void *src, size_t n);

#ifdef CONFIG_X86_64
#define memptr long
#else
#define memptr unsigned
#endif

static memptr free_mem_ptr;
static memptr free_mem_end_ptr;

static char *vidmem;
static int vidport;
static int lines, cols;

#ifdef CONFIG_KERNEL_GZIP
#include "../../../../lib/decompress_inflate.c"
#endif

#ifdef CONFIG_KERNEL_BZIP2
#include "../../../../lib/decompress_bunzip2.c"
#endif

#ifdef CONFIG_KERNEL_LZMA
#include "../../../../lib/decompress_unlzma.c"
#endif

#ifdef CONFIG_KERNEL_LZO
#include "../../../../lib/decompress_unlzo.c"
#endif

static void scroll(void)
{
	int i;

	memcpy(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
	for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
		vidmem[i] = ' ';
}

#define XMTRDY          0x20

#define TXR             0       /*  Transmit register (WRITE) */
#define LSR             5       /*  Line Status               */
static void serial_putchar(int ch)
{
	unsigned timeout = 0xffff;

	while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
		cpu_relax();

	outb(ch, early_serial_base + TXR);
}

void __putstr(int error, const char *s)
{
	int x, y, pos;
	char c;

#ifndef CONFIG_X86_VERBOSE_BOOTUP
	if (!error)
		return;
#endif
	if (early_serial_base) {
		const char *str = s;
		while (*str) {
			if (*str == '\n')
				serial_putchar('\r');
			serial_putchar(*str++);
		}
	}

	if (real_mode->screen_info.orig_video_mode == 0 &&
	    lines == 0 && cols == 0)
		return;

	x = real_mode->screen_info.orig_x;
	y = real_mode->screen_info.orig_y;

	while ((c = *s++) != '\0') {
		if (c == '\n') {
			x = 0;
			if (++y >= lines) {
				scroll();
				y--;
			}
		} else {
			vidmem[(x + cols * y) * 2] = c;
			if (++x >= cols) {
				x = 0;
				if (++y >= lines) {
					scroll();
					y--;
				}
			}
		}
	}

	real_mode->screen_info.orig_x = x;
	real_mode->screen_info.orig_y = y;

	pos = (x + cols * y) * 2;	/* Update cursor position */
	outb(14, vidport);
	outb(0xff & (pos >> 9), vidport+1);
	outb(15, vidport);
	outb(0xff & (pos >> 1), vidport+1);
}

void *memset(void *s, int c, size_t n)
{
	int i;
	char *ss = s;

	for (i = 0; i < n; i++)
		ss[i] = c;
	return s;
}

void *memcpy(void *dest, const void *src, size_t n)
{
	int i;
	const char *s = src;
	char *d = dest;

	for (i = 0; i < n; i++)
		d[i] = s[i];
	return dest;
}


static void error(char *x)
{
	__putstr(1, "\n\n");
	__putstr(1, x);
	__putstr(1, "\n\n -- System halted");

	while (1)
		asm("hlt");
}

static void parse_elf(void *output)
{
#ifdef CONFIG_X86_64
	Elf64_Ehdr ehdr;
	Elf64_Phdr *phdrs, *phdr;
#else
	Elf32_Ehdr ehdr;
	Elf32_Phdr *phdrs, *phdr;
#endif
	void *dest;
	int i;

	memcpy(&ehdr, output, sizeof(ehdr));
	if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
	   ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
	   ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
	   ehdr.e_ident[EI_MAG3] != ELFMAG3) {
		error("Kernel is not a valid ELF file");
		return;
	}

	if (!quiet)
		putstr("Parsing ELF... ");

	phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
	if (!phdrs)
		error("Failed to allocate space for phdrs");

	memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);

	for (i = 0; i < ehdr.e_phnum; i++) {
		phdr = &phdrs[i];

		switch (phdr->p_type) {
		case PT_LOAD:
#ifdef CONFIG_RELOCATABLE
			dest = output;
			dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
#else
			dest = (void *)(phdr->p_paddr);
#endif
			memcpy(dest,
			       output + phdr->p_offset,
			       phdr->p_filesz);
			break;
		default: /* Ignore other PT_* */ break;
		}
	}
}

asmlinkage void decompress_kernel(void *rmode, memptr heap,
				  unsigned char *input_data,
				  unsigned long input_len,
				  unsigned char *output)
{
	real_mode = rmode;

	if (cmdline_find_option_bool("quiet"))
		quiet = 1;
	if (cmdline_find_option_bool("debug"))
		debug = 1;

	if (real_mode->screen_info.orig_video_mode == 7) {
		vidmem = (char *) 0xb0000;
		vidport = 0x3b4;
	} else {
		vidmem = (char *) 0xb8000;
		vidport = 0x3d4;
	}

	lines = real_mode->screen_info.orig_video_lines;
	cols = real_mode->screen_info.orig_video_cols;

	console_init();
	if (debug)
		putstr("early console in decompress_kernel\n");

	free_mem_ptr     = heap;	/* Heap */
	free_mem_end_ptr = heap + BOOT_HEAP_SIZE;

	if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
		error("Destination address inappropriately aligned");
#ifdef CONFIG_X86_64
	if (heap > 0x3fffffffffffUL)
		error("Destination address too large");
#else
	if (heap > ((-__PAGE_OFFSET-(512<<20)-1) & 0x7fffffff))
		error("Destination address too large");
#endif
#ifndef CONFIG_RELOCATABLE
	if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
		error("Wrong destination address");
#endif

	if (!quiet)
		putstr("\nDecompressing Linux... ");
	decompress(input_data, input_len, NULL, NULL, output, NULL, error);
	parse_elf(output);
	if (!quiet)
		putstr("done.\nBooting the kernel.\n");
	return;
}
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* misc.c
818a08f8 IC	3	*
818a08f8 IC	4	* This is a collection of several routines from gzip-1.0.3
1da177e4 LT	5	* adapted for Linux.
	6	*
	7	* malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
	8	* puts by Nick Holloway 1993, better puts by Martin Mares 1995
	9	* High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
	10	*/
	11
8fee13a4	12	#include "misc.h"
968de4f0 EB	13
	14	/* WARNING!!
	15	* This code is compiled with -fPIC and it is relocated dynamically
	16	* at run time, but no relocation processing is performed.
	17	* This means that it is not safe to place pointers in static structures.
	18	*/
	19
	20	/*
	21	* Getting to provable safe in place decompression is hard.
27b46d76	22	* Worst case behaviours need to be analyzed.
968de4f0 EB	23	* Background information:
	24	*
	25	* The file layout is:
	26	* magic[2]
	27	* method[1]
	28	* flags[1]
	29	* timestamp[4]
	30	* extraflags[1]
	31	* os[1]
	32	* compressed data blocks[N]
	33	* crc[4] orig_len[4]
	34	*
	35	* resulting in 18 bytes of non compressed data overhead.
	36	*
	37	* Files divided into blocks
	38	* 1 bit (last block flag)
	39	* 2 bits (block type)
	40	*
1180e01d IM	41	* 1 block occurs every 32K -1 bytes or when there 50% compression
1180e01d IM	42	* has been achieved. The smallest block type encoding is always used.
968de4f0 EB	43	*
	44	* stored:
	45	* 32 bits length in bytes.
	46	*
	47	* fixed:
	48	* magic fixed tree.
	49	* symbols.
	50	*
	51	* dynamic:
	52	* dynamic tree encoding.
	53	* symbols.
	54	*
	55	*
	56	* The buffer for decompression in place is the length of the
	57	* uncompressed data, plus a small amount extra to keep the algorithm safe.
	58	* The compressed data is placed at the end of the buffer. The output
	59	* pointer is placed at the start of the buffer and the input pointer
	60	* is placed where the compressed data starts. Problems will occur
	61	* when the output pointer overruns the input pointer.
	62	*
	63	* The output pointer can only overrun the input pointer if the input
	64	* pointer is moving faster than the output pointer. A condition only
	65	* triggered by data whose compressed form is larger than the uncompressed
	66	* form.
	67	*
	68	* The worst case at the block level is a growth of the compressed data
	69	* of 5 bytes per 32767 bytes.
	70	*
	71	* The worst case internal to a compressed block is very hard to figure.
	72	* The worst case can at least be boundined by having one bit that represents
	73	* 32764 bytes and then all of the rest of the bytes representing the very
	74	* very last byte.
	75	*
	76	* All of which is enough to compute an amount of extra data that is required
	77	* to be safe. To avoid problems at the block level allocating 5 extra bytes
1180e01d IM	78	* per 32767 bytes of data is sufficient. To avoind problems internal to a
	79	* block adding an extra 32767 bytes (the worst case uncompressed block size)
	80	* is sufficient, to ensure that in the worst case the decompressed data for
968de4f0 EB	81	* block will stop the byte before the compressed data for a block begins.
	82	* To avoid problems with the compressed data's meta information an extra 18
	83	* bytes are needed. Leading to the formula:
	84	*
	85	* extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
	86	*
	87	* Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
	88	* Adding 32768 instead of 32767 just makes for round numbers.
	89	* Adding the decompressor_size is necessary as it musht live after all
	90	* of the data as well. Last I measured the decompressor is about 14K.
27b46d76	91	* 10K of actual data and 4K of bss.
968de4f0 EB	92	*
968de4f0 EB	93	*/
1da177e4 LT	94
	95	/*
	96	* gzip declarations
	97	*/
1180e01d	98	#define STATIC static
1da177e4 LT	99
	100	#undef memset
	101	#undef memcpy
1180e01d	102	#define memzero(s, n) memset((s), 0, (n))
1da177e4	103
1da177e4	104
1da177e4	105	static void error(char *m);
fd77c7ca	106
1da177e4 LT	107	/*
	108	* This is set up by the setup-routine at boot-time
	109	*/
8fee13a4	110	struct boot_params real_mode; / Pointer to real-mode data */
3b6b9293	111	static int quiet;
8fee13a4	112	static int debug;
1da177e4	113
6175ddf0 BG	114	void memset(void s, int c, size_t n);
6175ddf0 BG	115	void memcpy(void dest, const void *src, size_t n);
b79c4df7	116
778cb929 IC	117	#ifdef CONFIG_X86_64
	118	#define memptr long
	119	#else
	120	#define memptr unsigned
	121	#endif
	122
	123	static memptr free_mem_ptr;
	124	static memptr free_mem_end_ptr;
1da177e4	125
03056c88	126	static char *vidmem;
1da177e4 LT	127	static int vidport;
	128	static int lines, cols;
	129
ae03c499 AK	130	#ifdef CONFIG_KERNEL_GZIP
	131	#include "../../../../lib/decompress_inflate.c"
	132	#endif
	133
	134	#ifdef CONFIG_KERNEL_BZIP2
	135	#include "../../../../lib/decompress_bunzip2.c"
	136	#endif
	137
	138	#ifdef CONFIG_KERNEL_LZMA
	139	#include "../../../../lib/decompress_unlzma.c"
	140	#endif
1da177e4	141
13510997 AT	142	#ifdef CONFIG_KERNEL_LZO
	143	#include "../../../../lib/decompress_unlzo.c"
	144	#endif
	145
1da177e4 LT	146	static void scroll(void)
	147	{
	148	int i;
	149
fd77c7ca PC	150	memcpy(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
fd77c7ca PC	151	for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
1da177e4 LT	152	vidmem[i] = ' ';
	153	}
	154
8fee13a4 YL	155	#define XMTRDY 0x20
	156
	157	#define TXR 0 /* Transmit register (WRITE) */
	158	#define LSR 5 /* Line Status */
	159	static void serial_putchar(int ch)
	160	{
	161	unsigned timeout = 0xffff;
	162
	163	while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
	164	cpu_relax();
	165
	166	outb(ch, early_serial_base + TXR);
	167	}
	168
	169	void __putstr(int error, const char *s)
1da177e4	170	{
fd77c7ca	171	int x, y, pos;
1da177e4 LT	172	char c;
1da177e4 LT	173
6bcb13b3 BC	174	#ifndef CONFIG_X86_VERBOSE_BOOTUP
	175	if (!error)
	176	return;
	177	#endif
8fee13a4 YL	178	if (early_serial_base) {
	179	const char *str = s;
	180	while (*str) {
	181	if (*str == '\n')
	182	serial_putchar('\r');
	183	serial_putchar(*str++);
	184	}
	185	}
6bcb13b3	186
23968f71 KH	187	if (real_mode->screen_info.orig_video_mode == 0 &&
23968f71 KH	188	lines == 0 && cols == 0)
a24e7851 RR	189	return;
a24e7851 RR	190
23968f71 KH	191	x = real_mode->screen_info.orig_x;
23968f71 KH	192	y = real_mode->screen_info.orig_y;
1da177e4	193
fd77c7ca PC	194	while ((c = *s++) != '\0') {
fd77c7ca PC	195	if (c == '\n') {
1da177e4	196	x = 0;
fd77c7ca	197	if (++y >= lines) {
1da177e4 LT	198	scroll();
	199	y--;
	200	}
	201	} else {
020878ac	202	vidmem[(x + cols * y) * 2] = c;
fd77c7ca	203	if (++x >= cols) {
1da177e4	204	x = 0;
fd77c7ca	205	if (++y >= lines) {
1da177e4 LT	206	scroll();
	207	y--;
	208	}
	209	}
	210	}
	211	}
	212
23968f71 KH	213	real_mode->screen_info.orig_x = x;
23968f71 KH	214	real_mode->screen_info.orig_y = y;
1da177e4 LT	215
1da177e4 LT	216	pos = (x + cols * y) * 2; /* Update cursor position */
b02aae9c RH	217	outb(14, vidport);
	218	outb(0xff & (pos >> 9), vidport+1);
	219	outb(15, vidport);
	220	outb(0xff & (pos >> 1), vidport+1);
1da177e4 LT	221	}
1da177e4 LT	222
6175ddf0	223	void memset(void s, int c, size_t n)
1da177e4 LT	224	{
1da177e4 LT	225	int i;
ade1af77	226	char *ss = s;
1da177e4	227
020878ac PC	228	for (i = 0; i < n; i++)
020878ac PC	229	ss[i] = c;
1da177e4 LT	230	return s;
	231	}
	232
6175ddf0	233	void memcpy(void dest, const void *src, size_t n)
1da177e4 LT	234	{
1da177e4 LT	235	int i;
ade1af77 JE	236	const char *s = src;
ade1af77 JE	237	char *d = dest;
1da177e4	238
020878ac PC	239	for (i = 0; i < n; i++)
020878ac PC	240	d[i] = s[i];
b79c4df7	241	return dest;
1da177e4 LT	242	}
1da177e4 LT	243
1da177e4 LT	244
	245	static void error(char *x)
	246	{
6bcb13b3 BC	247	__putstr(1, "\n\n");
	248	__putstr(1, x);
	249	__putstr(1, "\n\n -- System halted");
1da177e4	250
ff3cf856 IM	251	while (1)
ff3cf856 IM	252	asm("hlt");
1da177e4 LT	253	}
1da177e4 LT	254
099e1377 IC	255	static void parse_elf(void *output)
	256	{
	257	#ifdef CONFIG_X86_64
	258	Elf64_Ehdr ehdr;
	259	Elf64_Phdr phdrs, phdr;
	260	#else
	261	Elf32_Ehdr ehdr;
	262	Elf32_Phdr phdrs, phdr;
	263	#endif
	264	void *dest;
	265	int i;
	266
	267	memcpy(&ehdr, output, sizeof(ehdr));
fd77c7ca	268	if (ehdr.e_ident[EI_MAG0] != ELFMAG0 \|\|
099e1377 IC	269	ehdr.e_ident[EI_MAG1] != ELFMAG1 \|\|
099e1377 IC	270	ehdr.e_ident[EI_MAG2] != ELFMAG2 \|\|
fd77c7ca	271	ehdr.e_ident[EI_MAG3] != ELFMAG3) {
099e1377 IC	272	error("Kernel is not a valid ELF file");
	273	return;
	274	}
	275
3b6b9293 KH	276	if (!quiet)
3b6b9293 KH	277	putstr("Parsing ELF... ");
099e1377 IC	278
	279	phdrs = malloc(sizeof(phdrs) ehdr.e_phnum);
	280	if (!phdrs)
	281	error("Failed to allocate space for phdrs");
	282
	283	memcpy(phdrs, output + ehdr.e_phoff, sizeof(phdrs) ehdr.e_phnum);
	284
fd77c7ca	285	for (i = 0; i < ehdr.e_phnum; i++) {
099e1377 IC	286	phdr = &phdrs[i];
	287
	288	switch (phdr->p_type) {
	289	case PT_LOAD:
	290	#ifdef CONFIG_RELOCATABLE
	291	dest = output;
	292	dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
	293	#else
fd77c7ca	294	dest = (void *)(phdr->p_paddr);
099e1377 IC	295	#endif
	296	memcpy(dest,
	297	output + phdr->p_offset,
	298	phdr->p_filesz);
	299	break;
	300	default: /* Ignore other PT_* */ break;
	301	}
	302	}
	303	}
	304
778cb929	305	asmlinkage void decompress_kernel(void *rmode, memptr heap,
1180e01d IM	306	unsigned char *input_data,
	307	unsigned long input_len,
	308	unsigned char *output)
1da177e4 LT	309	{
	310	real_mode = rmode;
	311
8fee13a4	312	if (cmdline_find_option_bool("quiet"))
3b6b9293	313	quiet = 1;
8fee13a4 YL	314	if (cmdline_find_option_bool("debug"))
8fee13a4 YL	315	debug = 1;
3b6b9293	316
23968f71	317	if (real_mode->screen_info.orig_video_mode == 7) {
1da177e4 LT	318	vidmem = (char *) 0xb0000;
	319	vidport = 0x3b4;
	320	} else {
	321	vidmem = (char *) 0xb8000;
	322	vidport = 0x3d4;
	323	}
	324
23968f71 KH	325	lines = real_mode->screen_info.orig_video_lines;
23968f71 KH	326	cols = real_mode->screen_info.orig_video_cols;
1da177e4	327
8fee13a4 YL	328	console_init();
	329	if (debug)
	330	putstr("early console in decompress_kernel\n");
	331
4c83d653	332	free_mem_ptr = heap; /* Heap */
7c539764	333	free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
968de4f0	334
7ed42a28 PA	335	if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
7ed42a28 PA	336	error("Destination address inappropriately aligned");
778cb929	337	#ifdef CONFIG_X86_64
7ed42a28	338	if (heap > 0x3fffffffffffUL)
778cb929 IC	339	error("Destination address too large");
778cb929 IC	340	#else
4c83d653	341	if (heap > ((-__PAGE_OFFSET-(512<<20)-1) & 0x7fffffff))
968de4f0	342	error("Destination address too large");
7ed42a28	343	#endif
968de4f0	344	#ifndef CONFIG_RELOCATABLE
7ed42a28	345	if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
968de4f0 EB	346	error("Wrong destination address");
968de4f0 EB	347	#endif
1da177e4	348
3b6b9293 KH	349	if (!quiet)
3b6b9293 KH	350	putstr("\nDecompressing Linux... ");
ae03c499	351	decompress(input_data, input_len, NULL, NULL, output, NULL, error);
099e1377	352	parse_elf(output);
3b6b9293 KH	353	if (!quiet)
3b6b9293 KH	354	putstr("done.\nBooting the kernel.\n");
968de4f0	355	return;
1da177e4	356	}