[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
 */

/*
 * we have to be careful, because no indirections are allowed here, and
 * paravirt_ops is a kind of one. As it will only run in baremetal anyway,
 * we just keep it from happening
 */
#undef CONFIG_PARAVIRT
#ifdef CONFIG_X86_32
#define _ASM_DESC_H_ 1
#endif

#ifdef CONFIG_X86_64
#define _LINUX_STRING_H_ 1
#define __LINUX_BITMAP_H 1
#endif

#include <linux/linkage.h>
#include <linux/screen_info.h>
#include <linux/elf.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/boot.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 OF(args)  args
#define STATIC static

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

typedef unsigned char  uch;
typedef unsigned short ush;
typedef unsigned long  ulg;

#define WSIZE 0x80000000	/*
				 * Window size must be at least 32k,
				 * and a power of two
				 * We don't actually have a window just
				 * a huge output buffer so I report
				 * a 2G windows size, as that should
				 * always be larger than our output buffer.
				 */

static uch *inbuf;	/* input buffer */
static uch *window;	/* Sliding window buffer, (and final output buffer) */

static unsigned insize;  /* valid bytes in inbuf */
static unsigned inptr;   /* index of next byte to be processed in inbuf */
static unsigned outcnt;  /* bytes in output buffer */

/* gzip flag byte */
#define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
#define ORIG_NAME    0x08 /* bit 3 set: original file name present */
#define COMMENT      0x10 /* bit 4 set: file comment present */
#define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
#define RESERVED     0xC0 /* bit 6,7:   reserved */

#define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf())

/* Diagnostic functions */
#ifdef DEBUG
#  define Assert(cond, msg) {if(!(cond)) error(msg); }
#  define Trace(x) fprintf x
#  define Tracev(x) {if (verbose) fprintf x ; }
#  define Tracevv(x) {if (verbose > 1) fprintf x ; }
#  define Tracec(c, x) {if (verbose && (c)) fprintf x ; }
#  define Tracecv(c, x) {if (verbose > 1 && (c)) fprintf x ; }
#else
#  define Assert(cond, msg)
#  define Trace(x)
#  define Tracev(x)
#  define Tracevv(x)
#  define Tracec(c, x)
#  define Tracecv(c, x)
#endif

static int  fill_inbuf(void);
static void flush_window(void);
static void error(char *m);
static void gzip_mark(void **);
static void gzip_release(void **);

/*
 * This is set up by the setup-routine at boot-time
 */
static unsigned char *real_mode; /* Pointer to real-mode data */

#define RM_EXT_MEM_K   (*(unsigned short *)(real_mode + 0x2))
#ifndef STANDARD_MEMORY_BIOS_CALL
#define RM_ALT_MEM_K   (*(unsigned long *)(real_mode + 0x1e0))
#endif
#define RM_SCREEN_INFO (*(struct screen_info *)(real_mode+0))

extern unsigned char input_data[];
extern int input_len;

static long bytes_out;

static void *malloc(int size);
static void free(void *where);

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

static void putstr(const char *);

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

static memptr free_mem_ptr;
static memptr free_mem_end_ptr;

#ifdef CONFIG_X86_64
#define HEAP_SIZE             0x7000
#else
#define HEAP_SIZE             0x4000
#endif

static char *vidmem = (char *)0xb8000;
static int vidport;
static int lines, cols;

#ifdef CONFIG_X86_NUMAQ
void *xquad_portio;
#endif

#include "../../../../lib/inflate.c"

static void *malloc(int size)
{
	void *p;

	if (size < 0)
		error("Malloc error");
	if (free_mem_ptr <= 0)
		error("Memory error");

	free_mem_ptr = (free_mem_ptr + 3) & ~3;	/* Align */

	p = (void *)free_mem_ptr;
	free_mem_ptr += size;

	if (free_mem_ptr >= free_mem_end_ptr)
		error("Out of memory");

	return p;
}

static void free(void *where)
{	/* Don't care */
}

static void gzip_mark(void **ptr)
{
	*ptr = (void *) free_mem_ptr;
}

static void gzip_release(void **ptr)
{
	free_mem_ptr = (memptr) *ptr;
}

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] = ' ';
}

static void putstr(const char *s)
{
	int x, y, pos;
	char c;

#ifdef CONFIG_X86_32
	if (RM_SCREEN_INFO.orig_video_mode == 0 && lines == 0 && cols == 0)
		return;
#endif

	x = RM_SCREEN_INFO.orig_x;
	y = RM_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--;
				}
			}
		}
	}

	RM_SCREEN_INFO.orig_x = x;
	RM_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);
}

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

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

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

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

/* ===========================================================================
 * Fill the input buffer. This is called only when the buffer is empty
 * and at least one byte is really needed.
 */
static int fill_inbuf(void)
{
	error("ran out of input data");
	return 0;
}

/* ===========================================================================
 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 * (Used for the decompressed data only.)
 */
static void flush_window(void)
{
	/* With my window equal to my output buffer
	 * I only need to compute the crc here.
	 */
	ulg c = crc;         /* temporary variable */
	unsigned n;
	uch *in, ch;

	in = window;
	for (n = 0; n < outcnt; n++) {
		ch = *in++;
		c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
	}
	crc = c;
	bytes_out += (ulg)outcnt;
	outcnt = 0;
}

static void error(char *x)
{
	putstr("\n\n");
	putstr(x);
	putstr("\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;
	}

	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,
				  uch *input_data, unsigned long input_len,
				  uch *output)
{
	real_mode = rmode;

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

	lines = RM_SCREEN_INFO.orig_video_lines;
	cols = RM_SCREEN_INFO.orig_video_cols;

	window = output;		/* Output buffer (Normally at 1M) */
	free_mem_ptr     = heap;	/* Heap */
	free_mem_end_ptr = heap + HEAP_SIZE;
	inbuf  = input_data;		/* Input buffer */
	insize = input_len;
	inptr  = 0;

#ifdef CONFIG_X86_64
	if ((ulg)output & (__KERNEL_ALIGN - 1))
		error("Destination address not 2M aligned");
	if ((ulg)output >= 0xffffffffffUL)
		error("Destination address too large");
#else
	if ((u32)output & (CONFIG_PHYSICAL_ALIGN -1))
		error("Destination address not CONFIG_PHYSICAL_ALIGN aligned");
	if (heap > ((-__PAGE_OFFSET-(512<<20)-1) & 0x7fffffff))
		error("Destination address too large");
#ifndef CONFIG_RELOCATABLE
	if ((u32)output != LOAD_PHYSICAL_ADDR)
		error("Wrong destination address");
#endif
#endif

	makecrc();
	putstr("\nDecompressing Linux... ");
	gunzip();
	parse_elf(output);
	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
818a08f8 IC	12	/*
	13	* we have to be careful, because no indirections are allowed here, and
	14	* paravirt_ops is a kind of one. As it will only run in baremetal anyway,
	15	* we just keep it from happening
	16	*/
d3561b7f	17	#undef CONFIG_PARAVIRT
099e1377 IC	18	#ifdef CONFIG_X86_32
	19	#define _ASM_DESC_H_ 1
	20	#endif
	21
778cb929 IC	22	#ifdef CONFIG_X86_64
	23	#define _LINUX_STRING_H_ 1
	24	#define __LINUX_BITMAP_H 1
	25	#endif
	26
1da177e4	27	#include <linux/linkage.h>
7e7f358c	28	#include <linux/screen_info.h>
099e1377	29	#include <linux/elf.h>
1da177e4	30	#include <asm/io.h>
968de4f0	31	#include <asm/page.h>
e69f202d	32	#include <asm/boot.h>
968de4f0 EB	33
	34	/* WARNING!!
	35	* This code is compiled with -fPIC and it is relocated dynamically
	36	* at run time, but no relocation processing is performed.
	37	* This means that it is not safe to place pointers in static structures.
	38	*/
	39
	40	/*
	41	* Getting to provable safe in place decompression is hard.
27b46d76	42	* Worst case behaviours need to be analyzed.
968de4f0 EB	43	* Background information:
	44	*
	45	* The file layout is:
	46	* magic[2]
	47	* method[1]
	48	* flags[1]
	49	* timestamp[4]
	50	* extraflags[1]
	51	* os[1]
	52	* compressed data blocks[N]
	53	* crc[4] orig_len[4]
	54	*
	55	* resulting in 18 bytes of non compressed data overhead.
	56	*
	57	* Files divided into blocks
	58	* 1 bit (last block flag)
	59	* 2 bits (block type)
	60	*
	61	* 1 block occurs every 32K -1 bytes or when there 50% compression has been achieved.
	62	* The smallest block type encoding is always used.
	63	*
	64	* stored:
	65	* 32 bits length in bytes.
	66	*
	67	* fixed:
	68	* magic fixed tree.
	69	* symbols.
	70	*
	71	* dynamic:
	72	* dynamic tree encoding.
	73	* symbols.
	74	*
	75	*
	76	* The buffer for decompression in place is the length of the
	77	* uncompressed data, plus a small amount extra to keep the algorithm safe.
	78	* The compressed data is placed at the end of the buffer. The output
	79	* pointer is placed at the start of the buffer and the input pointer
	80	* is placed where the compressed data starts. Problems will occur
	81	* when the output pointer overruns the input pointer.
	82	*
	83	* The output pointer can only overrun the input pointer if the input
	84	* pointer is moving faster than the output pointer. A condition only
	85	* triggered by data whose compressed form is larger than the uncompressed
	86	* form.
	87	*
	88	* The worst case at the block level is a growth of the compressed data
	89	* of 5 bytes per 32767 bytes.
	90	*
	91	* The worst case internal to a compressed block is very hard to figure.
	92	* The worst case can at least be boundined by having one bit that represents
	93	* 32764 bytes and then all of the rest of the bytes representing the very
	94	* very last byte.
	95	*
	96	* All of which is enough to compute an amount of extra data that is required
	97	* to be safe. To avoid problems at the block level allocating 5 extra bytes
	98	* per 32767 bytes of data is sufficient. To avoind problems internal to a block
	99	* adding an extra 32767 bytes (the worst case uncompressed block size) is
	100	* sufficient, to ensure that in the worst case the decompressed data for
	101	* block will stop the byte before the compressed data for a block begins.
	102	* To avoid problems with the compressed data's meta information an extra 18
	103	* bytes are needed. Leading to the formula:
	104	*
	105	* extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
	106	*
107	* Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
108	* Adding 32768 instead of 32767 just makes for round numbers.
109	* Adding the decompressor_size is necessary as it musht live after all
110	* of the data as well. Last I measured the decompressor is about 14K.
27b46d76	111	* 10K of actual data and 4K of bss.
968de4f0 EB	112	*
968de4f0 EB	113	*/
1da177e4 LT	114
	115	/*
	116	* gzip declarations
	117	*/
	118
	119	#define OF(args) args
	120	#define STATIC static
	121
	122	#undef memset
	123	#undef memcpy
1da177e4 LT	124	#define memzero(s, n) memset ((s), 0, (n))
	125
	126	typedef unsigned char uch;
	127	typedef unsigned short ush;
	128	typedef unsigned long ulg;
	129
fd77c7ca PC	130	#define WSIZE 0x80000000 /*
fd77c7ca PC	131	* Window size must be at least 32k,
968de4f0 EB	132	* and a power of two
	133	* We don't actually have a window just
	134	* a huge output buffer so I report
	135	* a 2G windows size, as that should
	136	* always be larger than our output buffer.
	137	*/
1da177e4	138
968de4f0 EB	139	static uch inbuf; / input buffer */
968de4f0 EB	140	static uch window; / Sliding window buffer, (and final output buffer) */
1da177e4	141
968de4f0 EB	142	static unsigned insize; /* valid bytes in inbuf */
	143	static unsigned inptr; /* index of next byte to be processed in inbuf */
	144	static unsigned outcnt; /* bytes in output buffer */
1da177e4 LT	145
	146	/* gzip flag byte */
	147	#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
	148	#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
	149	#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
	150	#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
	151	#define COMMENT 0x10 /* bit 4 set: file comment present */
	152	#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
	153	#define RESERVED 0xC0 /* bit 6,7: reserved */
	154
	155	#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf())
fd77c7ca	156
1da177e4 LT	157	/* Diagnostic functions */
1da177e4 LT	158	#ifdef DEBUG
fd77c7ca	159	# define Assert(cond, msg) {if(!(cond)) error(msg); }
1da177e4	160	# define Trace(x) fprintf x
fd77c7ca PC	161	# define Tracev(x) {if (verbose) fprintf x ; }
	162	# define Tracevv(x) {if (verbose > 1) fprintf x ; }
	163	# define Tracec(c, x) {if (verbose && (c)) fprintf x ; }
	164	# define Tracecv(c, x) {if (verbose > 1 && (c)) fprintf x ; }
1da177e4	165	#else
fd77c7ca	166	# define Assert(cond, msg)
1da177e4 LT	167	# define Trace(x)
	168	# define Tracev(x)
	169	# define Tracevv(x)
fd77c7ca PC	170	# define Tracec(c, x)
fd77c7ca PC	171	# define Tracecv(c, x)
1da177e4 LT	172	#endif
	173
	174	static int fill_inbuf(void);
	175	static void flush_window(void);
	176	static void error(char *m);
	177	static void gzip_mark(void **);
	178	static void gzip_release(void **);
fd77c7ca	179
1da177e4 LT	180	/*
	181	* This is set up by the setup-routine at boot-time
	182	*/
	183	static unsigned char real_mode; / Pointer to real-mode data */
	184
	185	#define RM_EXT_MEM_K ((unsigned short )(real_mode + 0x2))
	186	#ifndef STANDARD_MEMORY_BIOS_CALL
	187	#define RM_ALT_MEM_K ((unsigned long )(real_mode + 0x1e0))
	188	#endif
	189	#define RM_SCREEN_INFO ((struct screen_info )(real_mode+0))
	190
b79c4df7	191	extern unsigned char input_data[];
1da177e4 LT	192	extern int input_len;
1da177e4 LT	193
fd77c7ca	194	static long bytes_out;
1da177e4 LT	195
	196	static void *malloc(int size);
	197	static void free(void *where);
	198
b79c4df7 CDH	199	static void memset(void s, int c, unsigned n);
	200	static void memcpy(void dest, const void *src, unsigned n);
	201
1da177e4 LT	202	static void putstr(const char *);
1da177e4 LT	203
778cb929 IC	204	#ifdef CONFIG_X86_64
	205	#define memptr long
	206	#else
	207	#define memptr unsigned
	208	#endif
	209
	210	static memptr free_mem_ptr;
	211	static memptr free_mem_end_ptr;
1da177e4	212
778cb929 IC	213	#ifdef CONFIG_X86_64
	214	#define HEAP_SIZE 0x7000
	215	#else
35c74226	216	#define HEAP_SIZE 0x4000
778cb929	217	#endif
1da177e4 LT	218
	219	static char vidmem = (char )0xb8000;
	220	static int vidport;
	221	static int lines, cols;
	222
	223	#ifdef CONFIG_X86_NUMAQ
d5d2448d	224	void *xquad_portio;
1da177e4 LT	225	#endif
	226
	227	#include "../../../../lib/inflate.c"
	228
	229	static void *malloc(int size)
	230	{
	231	void *p;
	232
fd77c7ca PC	233	if (size < 0)
	234	error("Malloc error");
	235	if (free_mem_ptr <= 0)
	236	error("Memory error");
1da177e4 LT	237
	238	free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
	239
	240	p = (void *)free_mem_ptr;
	241	free_mem_ptr += size;
	242
	243	if (free_mem_ptr >= free_mem_end_ptr)
	244	error("Out of memory");
	245
	246	return p;
	247	}
	248
	249	static void free(void *where)
	250	{ /* Don't care */
	251	}
	252
	253	static void gzip_mark(void **ptr)
	254	{
	255	ptr = (void ) free_mem_ptr;
	256	}
	257
	258	static void gzip_release(void **ptr)
	259	{
778cb929	260	free_mem_ptr = (memptr) *ptr;
1da177e4	261	}
fd77c7ca	262
1da177e4 LT	263	static void scroll(void)
	264	{
	265	int i;
	266
fd77c7ca PC	267	memcpy(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
fd77c7ca PC	268	for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
1da177e4 LT	269	vidmem[i] = ' ';
	270	}
	271
	272	static void putstr(const char *s)
	273	{
fd77c7ca	274	int x, y, pos;
1da177e4 LT	275	char c;
1da177e4 LT	276
778cb929	277	#ifdef CONFIG_X86_32
a24e7851 RR	278	if (RM_SCREEN_INFO.orig_video_mode == 0 && lines == 0 && cols == 0)
a24e7851 RR	279	return;
778cb929	280	#endif
a24e7851	281
1da177e4 LT	282	x = RM_SCREEN_INFO.orig_x;
	283	y = RM_SCREEN_INFO.orig_y;
	284
fd77c7ca PC	285	while ((c = *s++) != '\0') {
fd77c7ca PC	286	if (c == '\n') {
1da177e4	287	x = 0;
fd77c7ca	288	if (++y >= lines) {
1da177e4 LT	289	scroll();
	290	y--;
	291	}
	292	} else {
818a08f8	293	vidmem [(x + cols * y) * 2] = c;
fd77c7ca	294	if (++x >= cols) {
1da177e4	295	x = 0;
fd77c7ca	296	if (++y >= lines) {
1da177e4 LT	297	scroll();
	298	y--;
	299	}
	300	}
	301	}
	302	}
	303
	304	RM_SCREEN_INFO.orig_x = x;
	305	RM_SCREEN_INFO.orig_y = y;
	306
	307	pos = (x + cols * y) * 2; /* Update cursor position */
b02aae9c RH	308	outb(14, vidport);
	309	outb(0xff & (pos >> 9), vidport+1);
	310	outb(15, vidport);
	311	outb(0xff & (pos >> 1), vidport+1);
1da177e4 LT	312	}
1da177e4 LT	313
fd77c7ca	314	static void memset(void s, int c, unsigned n)
1da177e4 LT	315	{
1da177e4 LT	316	int i;
ade1af77	317	char *ss = s;
1da177e4	318
fd77c7ca	319	for (i = 0; i < n; i++) ss[i] = c;
1da177e4 LT	320	return s;
	321	}
	322
fd77c7ca	323	static void memcpy(void dest, const void *src, unsigned n)
1da177e4 LT	324	{
1da177e4 LT	325	int i;
ade1af77 JE	326	const char *s = src;
ade1af77 JE	327	char *d = dest;
1da177e4	328
fd77c7ca	329	for (i = 0; i < n; i++) d[i] = s[i];
b79c4df7	330	return dest;
1da177e4 LT	331	}
	332
	333	/* ===========================================================================
	334	* Fill the input buffer. This is called only when the buffer is empty
	335	* and at least one byte is really needed.
	336	*/
	337	static int fill_inbuf(void)
	338	{
968de4f0 EB	339	error("ran out of input data");
968de4f0 EB	340	return 0;
1da177e4 LT	341	}
	342
	343	/* ===========================================================================
	344	* Write the output window window[0..outcnt-1] and update crc and bytes_out.
	345	* (Used for the decompressed data only.)
	346	*/
1da177e4 LT	347	static void flush_window(void)
1da177e4 LT	348	{
968de4f0 EB	349	/* With my window equal to my output buffer
	350	* I only need to compute the crc here.
	351	*/
	352	ulg c = crc; /* temporary variable */
	353	unsigned n;
	354	uch *in, ch;
	355
	356	in = window;
	357	for (n = 0; n < outcnt; n++) {
	358	ch = *in++;
	359	c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
	360	}
	361	crc = c;
	362	bytes_out += (ulg)outcnt;
	363	outcnt = 0;
1da177e4 LT	364	}
	365
	366	static void error(char *x)
	367	{
	368	putstr("\n\n");
	369	putstr(x);
	370	putstr("\n\n -- System halted");
	371
ff3cf856 IM	372	while (1)
ff3cf856 IM	373	asm("hlt");
1da177e4 LT	374	}
1da177e4 LT	375
099e1377 IC	376	static void parse_elf(void *output)
	377	{
	378	#ifdef CONFIG_X86_64
	379	Elf64_Ehdr ehdr;
	380	Elf64_Phdr phdrs, phdr;
	381	#else
	382	Elf32_Ehdr ehdr;
	383	Elf32_Phdr phdrs, phdr;
	384	#endif
	385	void *dest;
	386	int i;
	387
	388	memcpy(&ehdr, output, sizeof(ehdr));
fd77c7ca	389	if (ehdr.e_ident[EI_MAG0] != ELFMAG0 \|\|
099e1377 IC	390	ehdr.e_ident[EI_MAG1] != ELFMAG1 \|\|
099e1377 IC	391	ehdr.e_ident[EI_MAG2] != ELFMAG2 \|\|
fd77c7ca	392	ehdr.e_ident[EI_MAG3] != ELFMAG3) {
099e1377 IC	393	error("Kernel is not a valid ELF file");
	394	return;
	395	}
	396
	397	putstr("Parsing ELF... ");
	398
	399	phdrs = malloc(sizeof(phdrs) ehdr.e_phnum);
	400	if (!phdrs)
	401	error("Failed to allocate space for phdrs");
	402
	403	memcpy(phdrs, output + ehdr.e_phoff, sizeof(phdrs) ehdr.e_phnum);
	404
fd77c7ca	405	for (i = 0; i < ehdr.e_phnum; i++) {
099e1377 IC	406	phdr = &phdrs[i];
	407
	408	switch (phdr->p_type) {
	409	case PT_LOAD:
	410	#ifdef CONFIG_RELOCATABLE
	411	dest = output;
	412	dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
	413	#else
fd77c7ca	414	dest = (void *)(phdr->p_paddr);
099e1377 IC	415	#endif
	416	memcpy(dest,
	417	output + phdr->p_offset,
	418	phdr->p_filesz);
	419	break;
	420	default: /* Ignore other PT_* */ break;
	421	}
	422	}
	423	}
	424
778cb929	425	asmlinkage void decompress_kernel(void *rmode, memptr heap,
818a08f8 IC	426	uch *input_data, unsigned long input_len,
818a08f8 IC	427	uch *output)
1da177e4 LT	428	{
	429	real_mode = rmode;
	430
	431	if (RM_SCREEN_INFO.orig_video_mode == 7) {
	432	vidmem = (char *) 0xb0000;
	433	vidport = 0x3b4;
	434	} else {
	435	vidmem = (char *) 0xb8000;
	436	vidport = 0x3d4;
	437	}
	438
	439	lines = RM_SCREEN_INFO.orig_video_lines;
	440	cols = RM_SCREEN_INFO.orig_video_cols;
	441
818a08f8	442	window = output; /* Output buffer (Normally at 1M) */
4c83d653 IC	443	free_mem_ptr = heap; /* Heap */
4c83d653 IC	444	free_mem_end_ptr = heap + HEAP_SIZE;
818a08f8	445	inbuf = input_data; /* Input buffer */
968de4f0 EB	446	insize = input_len;
	447	inptr = 0;
	448
778cb929 IC	449	#ifdef CONFIG_X86_64
	450	if ((ulg)output & (__KERNEL_ALIGN - 1))
	451	error("Destination address not 2M aligned");
	452	if ((ulg)output >= 0xffffffffffUL)
	453	error("Destination address too large");
	454	#else
e69f202d VG	455	if ((u32)output & (CONFIG_PHYSICAL_ALIGN -1))
e69f202d VG	456	error("Destination address not CONFIG_PHYSICAL_ALIGN aligned");
4c83d653	457	if (heap > ((-__PAGE_OFFSET-(512<<20)-1) & 0x7fffffff))
968de4f0 EB	458	error("Destination address too large");
968de4f0 EB	459	#ifndef CONFIG_RELOCATABLE
e69f202d	460	if ((u32)output != LOAD_PHYSICAL_ADDR)
968de4f0	461	error("Wrong destination address");
778cb929	462	#endif
968de4f0	463	#endif
1da177e4 LT	464
1da177e4 LT	465	makecrc();
6b3c0426	466	putstr("\nDecompressing Linux... ");
1da177e4	467	gunzip();
099e1377	468	parse_elf(output);
6b3c0426	469	putstr("done.\nBooting the kernel.\n");
968de4f0	470	return;
1da177e4	471	}