[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>
#include <asm/bootparam.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;

/*
 * 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 we report a 2G window size, as that should always be
 * larger than our output buffer:
 */
#define WSIZE		0x80000000

/* Input buffer: */
static unsigned char	*inbuf;

/* Sliding window buffer (and final output buffer): */
static unsigned char	*window;

/* Valid bytes in inbuf: */
static unsigned		insize;

/* Index of next byte to be processed in inbuf: */
static unsigned		inptr;

/* Bytes in output buffer: */
static unsigned		outcnt;

/* gzip flag byte */
#define ASCII_FLAG	0x01 /* bit 0 set: file probably ASCII text */
#define CONTINUATION	0x02 /* bit 1 set: continuation of multi-part gz file */
#define EXTRA_FIELD	0x04 /* bit 2 set: extra field present */
#define ORIG_NAM	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) do { if (!(cond)) error(msg); } while (0)
#  define Trace(x)	do { fprintf x; } while (0)
#  define Tracev(x)	do { if (verbose) fprintf x ; } while (0)
#  define Tracevv(x)	do { if (verbose > 1) fprintf x ; } while (0)
#  define Tracec(c, x)	do { if (verbose && (c)) fprintf x ; } while (0)
#  define Tracecv(c, x)	do { if (verbose > 1 && (c)) fprintf x ; } while (0)
#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 struct boot_params *real_mode;		/* Pointer to real-mode data */

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;

static char *vidmem;
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 (real_mode->screen_info.orig_video_mode == 0 &&
	    lines == 0 && cols == 0)
		return;
#endif

	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);
}

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.
	 */
	unsigned long c = crc;         /* temporary variable */
	unsigned n;
	unsigned char *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 += (unsigned long)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,
				  unsigned char *input_data,
				  unsigned long input_len,
				  unsigned char *output)
{
	real_mode = rmode;

	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;

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

#ifdef CONFIG_X86_64
	if ((unsigned long)output & (__KERNEL_ALIGN - 1))
		error("Destination address not 2M aligned");
	if ((unsigned long)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>
23968f71	33	#include <asm/bootparam.h>
968de4f0 EB	34
	35	/* WARNING!!
	36	* This code is compiled with -fPIC and it is relocated dynamically
	37	* at run time, but no relocation processing is performed.
	38	* This means that it is not safe to place pointers in static structures.
	39	*/
	40
	41	/*
	42	* Getting to provable safe in place decompression is hard.
27b46d76	43	* Worst case behaviours need to be analyzed.
968de4f0 EB	44	* Background information:
	45	*
	46	* The file layout is:
	47	* magic[2]
	48	* method[1]
	49	* flags[1]
	50	* timestamp[4]
	51	* extraflags[1]
	52	* os[1]
	53	* compressed data blocks[N]
	54	* crc[4] orig_len[4]
	55	*
	56	* resulting in 18 bytes of non compressed data overhead.
	57	*
	58	* Files divided into blocks
	59	* 1 bit (last block flag)
	60	* 2 bits (block type)
	61	*
1180e01d IM	62	* 1 block occurs every 32K -1 bytes or when there 50% compression
1180e01d IM	63	* has been achieved. The smallest block type encoding is always used.
968de4f0 EB	64	*
	65	* stored:
	66	* 32 bits length in bytes.
	67	*
	68	* fixed:
	69	* magic fixed tree.
	70	* symbols.
	71	*
	72	* dynamic:
	73	* dynamic tree encoding.
	74	* symbols.
	75	*
	76	*
	77	* The buffer for decompression in place is the length of the
	78	* uncompressed data, plus a small amount extra to keep the algorithm safe.
	79	* The compressed data is placed at the end of the buffer. The output
	80	* pointer is placed at the start of the buffer and the input pointer
	81	* is placed where the compressed data starts. Problems will occur
	82	* when the output pointer overruns the input pointer.
	83	*
	84	* The output pointer can only overrun the input pointer if the input
	85	* pointer is moving faster than the output pointer. A condition only
	86	* triggered by data whose compressed form is larger than the uncompressed
	87	* form.
	88	*
	89	* The worst case at the block level is a growth of the compressed data
	90	* of 5 bytes per 32767 bytes.
	91	*
	92	* The worst case internal to a compressed block is very hard to figure.
	93	* The worst case can at least be boundined by having one bit that represents
	94	* 32764 bytes and then all of the rest of the bytes representing the very
	95	* very last byte.
	96	*
	97	* All of which is enough to compute an amount of extra data that is required
	98	* to be safe. To avoid problems at the block level allocating 5 extra bytes
1180e01d IM	99	* per 32767 bytes of data is sufficient. To avoind problems internal to a
	100	* block adding an extra 32767 bytes (the worst case uncompressed block size)
	101	* is sufficient, to ensure that in the worst case the decompressed data for
968de4f0 EB	102	* block will stop the byte before the compressed data for a block begins.
	103	* To avoid problems with the compressed data's meta information an extra 18
	104	* bytes are needed. Leading to the formula:
	105	*
	106	* extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
	107	*
	108	* Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
	109	* Adding 32768 instead of 32767 just makes for round numbers.
	110	* Adding the decompressor_size is necessary as it musht live after all
	111	* of the data as well. Last I measured the decompressor is about 14K.
27b46d76	112	* 10K of actual data and 4K of bss.
968de4f0 EB	113	*
968de4f0 EB	114	*/
1da177e4 LT	115
	116	/*
	117	* gzip declarations
	118	*/
	119
1180e01d IM	120	#define OF(args) args
1180e01d IM	121	#define STATIC static
1da177e4 LT	122
	123	#undef memset
	124	#undef memcpy
1180e01d	125	#define memzero(s, n) memset((s), 0, (n))
1da177e4	126
1180e01d IM	127	typedef unsigned char uch;
	128	typedef unsigned short ush;
	129	typedef unsigned long ulg;
1da177e4	130
1180e01d IM	131	/*
	132	* Window size must be at least 32k, and a power of two.
	133	* We don't actually have a window just a huge output buffer,
	134	* so we report a 2G window size, as that should always be
	135	* larger than our output buffer:
	136	*/
	137	#define WSIZE 0x80000000
	138
	139	/* Input buffer: */
	140	static unsigned char *inbuf;
	141
	142	/* Sliding window buffer (and final output buffer): */
	143	static unsigned char *window;
	144
	145	/* Valid bytes in inbuf: */
	146	static unsigned insize;
1da177e4	147
1180e01d IM	148	/* Index of next byte to be processed in inbuf: */
1180e01d IM	149	static unsigned inptr;
1da177e4	150
1180e01d IM	151	/* Bytes in output buffer: */
1180e01d IM	152	static unsigned outcnt;
1da177e4 LT	153
1da177e4 LT	154	/* gzip flag byte */
1180e01d IM	155	#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
	156	#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gz file */
	157	#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
	158	#define ORIG_NAM 0x08 /* bit 3 set: original file name present */
	159	#define COMMENT 0x10 /* bit 4 set: file comment present */
	160	#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
	161	#define RESERVED 0xC0 /* bit 6, 7: reserved */
1da177e4	162
1180e01d	163	#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf())
fd77c7ca	164
1da177e4 LT	165	/* Diagnostic functions */
1da177e4 LT	166	#ifdef DEBUG
1180e01d IM	167	# define Assert(cond, msg) do { if (!(cond)) error(msg); } while (0)
	168	# define Trace(x) do { fprintf x; } while (0)
	169	# define Tracev(x) do { if (verbose) fprintf x ; } while (0)
	170	# define Tracevv(x) do { if (verbose > 1) fprintf x ; } while (0)
	171	# define Tracec(c, x) do { if (verbose && (c)) fprintf x ; } while (0)
	172	# define Tracecv(c, x) do { if (verbose > 1 && (c)) fprintf x ; } while (0)
1da177e4	173	#else
fd77c7ca	174	# define Assert(cond, msg)
1da177e4 LT	175	# define Trace(x)
	176	# define Tracev(x)
	177	# define Tracevv(x)
fd77c7ca PC	178	# define Tracec(c, x)
fd77c7ca PC	179	# define Tracecv(c, x)
1da177e4 LT	180	#endif
	181
	182	static int fill_inbuf(void);
	183	static void flush_window(void);
	184	static void error(char *m);
	185	static void gzip_mark(void **);
	186	static void gzip_release(void **);
fd77c7ca	187
1da177e4 LT	188	/*
	189	* This is set up by the setup-routine at boot-time
	190	*/
23968f71	191	static struct boot_params real_mode; / Pointer to real-mode data */
1da177e4	192
b79c4df7	193	extern unsigned char input_data[];
1da177e4 LT	194	extern int input_len;
1da177e4 LT	195
fd77c7ca	196	static long bytes_out;
1da177e4 LT	197
	198	static void *malloc(int size);
	199	static void free(void *where);
	200
b79c4df7 CDH	201	static void memset(void s, int c, unsigned n);
	202	static void memcpy(void dest, const void *src, unsigned n);
	203
1da177e4 LT	204	static void putstr(const char *);
1da177e4 LT	205
778cb929 IC	206	#ifdef CONFIG_X86_64
	207	#define memptr long
	208	#else
	209	#define memptr unsigned
	210	#endif
	211
	212	static memptr free_mem_ptr;
	213	static memptr free_mem_end_ptr;
1da177e4	214
03056c88	215	static char *vidmem;
1da177e4 LT	216	static int vidport;
	217	static int lines, cols;
	218
	219	#ifdef CONFIG_X86_NUMAQ
d5d2448d	220	void *xquad_portio;
1da177e4 LT	221	#endif
	222
	223	#include "../../../../lib/inflate.c"
	224
	225	static void *malloc(int size)
	226	{
	227	void *p;
	228
fd77c7ca PC	229	if (size < 0)
	230	error("Malloc error");
	231	if (free_mem_ptr <= 0)
	232	error("Memory error");
1da177e4 LT	233
	234	free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
	235
	236	p = (void *)free_mem_ptr;
	237	free_mem_ptr += size;
	238
	239	if (free_mem_ptr >= free_mem_end_ptr)
	240	error("Out of memory");
	241
	242	return p;
	243	}
	244
	245	static void free(void *where)
	246	{ /* Don't care */
	247	}
	248
	249	static void gzip_mark(void **ptr)
	250	{
	251	ptr = (void ) free_mem_ptr;
	252	}
	253
	254	static void gzip_release(void **ptr)
	255	{
778cb929	256	free_mem_ptr = (memptr) *ptr;
1da177e4	257	}
fd77c7ca	258
1da177e4 LT	259	static void scroll(void)
	260	{
	261	int i;
	262
fd77c7ca PC	263	memcpy(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
fd77c7ca PC	264	for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
1da177e4 LT	265	vidmem[i] = ' ';
	266	}
	267
	268	static void putstr(const char *s)
	269	{
fd77c7ca	270	int x, y, pos;
1da177e4 LT	271	char c;
1da177e4 LT	272
778cb929	273	#ifdef CONFIG_X86_32
23968f71 KH	274	if (real_mode->screen_info.orig_video_mode == 0 &&
23968f71 KH	275	lines == 0 && cols == 0)
a24e7851	276	return;
778cb929	277	#endif
a24e7851	278
23968f71 KH	279	x = real_mode->screen_info.orig_x;
23968f71 KH	280	y = real_mode->screen_info.orig_y;
1da177e4	281
fd77c7ca PC	282	while ((c = *s++) != '\0') {
fd77c7ca PC	283	if (c == '\n') {
1da177e4	284	x = 0;
fd77c7ca	285	if (++y >= lines) {
1da177e4 LT	286	scroll();
	287	y--;
	288	}
	289	} else {
818a08f8	290	vidmem [(x + cols * y) * 2] = c;
fd77c7ca	291	if (++x >= cols) {
1da177e4	292	x = 0;
fd77c7ca	293	if (++y >= lines) {
1da177e4 LT	294	scroll();
	295	y--;
	296	}
	297	}
	298	}
	299	}
	300
23968f71 KH	301	real_mode->screen_info.orig_x = x;
23968f71 KH	302	real_mode->screen_info.orig_y = y;
1da177e4 LT	303
1da177e4 LT	304	pos = (x + cols * y) * 2; /* Update cursor position */
b02aae9c RH	305	outb(14, vidport);
	306	outb(0xff & (pos >> 9), vidport+1);
	307	outb(15, vidport);
	308	outb(0xff & (pos >> 1), vidport+1);
1da177e4 LT	309	}
1da177e4 LT	310
fd77c7ca	311	static void memset(void s, int c, unsigned n)
1da177e4 LT	312	{
1da177e4 LT	313	int i;
ade1af77	314	char *ss = s;
1da177e4	315
fd77c7ca	316	for (i = 0; i < n; i++) ss[i] = c;
1da177e4 LT	317	return s;
	318	}
	319
fd77c7ca	320	static void memcpy(void dest, const void *src, unsigned n)
1da177e4 LT	321	{
1da177e4 LT	322	int i;
ade1af77 JE	323	const char *s = src;
ade1af77 JE	324	char *d = dest;
1da177e4	325
fd77c7ca	326	for (i = 0; i < n; i++) d[i] = s[i];
b79c4df7	327	return dest;
1da177e4 LT	328	}
	329
	330	/* ===========================================================================
	331	* Fill the input buffer. This is called only when the buffer is empty
	332	* and at least one byte is really needed.
	333	*/
	334	static int fill_inbuf(void)
	335	{
968de4f0 EB	336	error("ran out of input data");
968de4f0 EB	337	return 0;
1da177e4 LT	338	}
	339
	340	/* ===========================================================================
	341	* Write the output window window[0..outcnt-1] and update crc and bytes_out.
	342	* (Used for the decompressed data only.)
	343	*/
1da177e4 LT	344	static void flush_window(void)
1da177e4 LT	345	{
968de4f0 EB	346	/* With my window equal to my output buffer
	347	* I only need to compute the crc here.
	348	*/
1180e01d	349	unsigned long c = crc; /* temporary variable */
968de4f0	350	unsigned n;
1180e01d	351	unsigned char *in, ch;
968de4f0 EB	352
	353	in = window;
	354	for (n = 0; n < outcnt; n++) {
	355	ch = *in++;
	356	c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
	357	}
	358	crc = c;
1180e01d	359	bytes_out += (unsigned long)outcnt;
968de4f0	360	outcnt = 0;
1da177e4 LT	361	}
	362
	363	static void error(char *x)
	364	{
	365	putstr("\n\n");
	366	putstr(x);
	367	putstr("\n\n -- System halted");
	368
ff3cf856 IM	369	while (1)
ff3cf856 IM	370	asm("hlt");
1da177e4 LT	371	}
1da177e4 LT	372
099e1377 IC	373	static void parse_elf(void *output)
	374	{
	375	#ifdef CONFIG_X86_64
	376	Elf64_Ehdr ehdr;
	377	Elf64_Phdr phdrs, phdr;
	378	#else
	379	Elf32_Ehdr ehdr;
	380	Elf32_Phdr phdrs, phdr;
	381	#endif
	382	void *dest;
	383	int i;
	384
	385	memcpy(&ehdr, output, sizeof(ehdr));
fd77c7ca	386	if (ehdr.e_ident[EI_MAG0] != ELFMAG0 \|\|
099e1377 IC	387	ehdr.e_ident[EI_MAG1] != ELFMAG1 \|\|
099e1377 IC	388	ehdr.e_ident[EI_MAG2] != ELFMAG2 \|\|
fd77c7ca	389	ehdr.e_ident[EI_MAG3] != ELFMAG3) {
099e1377 IC	390	error("Kernel is not a valid ELF file");
	391	return;
	392	}
	393
	394	putstr("Parsing ELF... ");
	395
	396	phdrs = malloc(sizeof(phdrs) ehdr.e_phnum);
	397	if (!phdrs)
	398	error("Failed to allocate space for phdrs");
	399
	400	memcpy(phdrs, output + ehdr.e_phoff, sizeof(phdrs) ehdr.e_phnum);
	401
fd77c7ca	402	for (i = 0; i < ehdr.e_phnum; i++) {
099e1377 IC	403	phdr = &phdrs[i];
	404
	405	switch (phdr->p_type) {
	406	case PT_LOAD:
	407	#ifdef CONFIG_RELOCATABLE
	408	dest = output;
	409	dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
	410	#else
fd77c7ca	411	dest = (void *)(phdr->p_paddr);
099e1377 IC	412	#endif
	413	memcpy(dest,
	414	output + phdr->p_offset,
	415	phdr->p_filesz);
	416	break;
	417	default: /* Ignore other PT_* */ break;
	418	}
	419	}
	420	}
	421
778cb929	422	asmlinkage void decompress_kernel(void *rmode, memptr heap,
1180e01d IM	423	unsigned char *input_data,
	424	unsigned long input_len,
	425	unsigned char *output)
1da177e4 LT	426	{
	427	real_mode = rmode;
	428
23968f71	429	if (real_mode->screen_info.orig_video_mode == 7) {
1da177e4 LT	430	vidmem = (char *) 0xb0000;
	431	vidport = 0x3b4;
	432	} else {
	433	vidmem = (char *) 0xb8000;
	434	vidport = 0x3d4;
	435	}
	436
23968f71 KH	437	lines = real_mode->screen_info.orig_video_lines;
23968f71 KH	438	cols = real_mode->screen_info.orig_video_cols;
1da177e4	439
818a08f8	440	window = output; /* Output buffer (Normally at 1M) */
4c83d653	441	free_mem_ptr = heap; /* Heap */
7c539764	442	free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
818a08f8	443	inbuf = input_data; /* Input buffer */
968de4f0 EB	444	insize = input_len;
	445	inptr = 0;
	446
778cb929	447	#ifdef CONFIG_X86_64
1180e01d	448	if ((unsigned long)output & (__KERNEL_ALIGN - 1))
778cb929	449	error("Destination address not 2M aligned");
1180e01d	450	if ((unsigned long)output >= 0xffffffffffUL)
778cb929 IC	451	error("Destination address too large");
778cb929 IC	452	#else
1180e01d	453	if ((u32)output & (CONFIG_PHYSICAL_ALIGN - 1))
e69f202d	454	error("Destination address not CONFIG_PHYSICAL_ALIGN aligned");
4c83d653	455	if (heap > ((-__PAGE_OFFSET-(512<<20)-1) & 0x7fffffff))
968de4f0 EB	456	error("Destination address too large");
968de4f0 EB	457	#ifndef CONFIG_RELOCATABLE
e69f202d	458	if ((u32)output != LOAD_PHYSICAL_ADDR)
968de4f0	459	error("Wrong destination address");
778cb929	460	#endif
968de4f0	461	#endif
1da177e4 LT	462
1da177e4 LT	463	makecrc();
6b3c0426	464	putstr("\nDecompressing Linux... ");
1da177e4	465	gunzip();
099e1377	466	parse_elf(output);
6b3c0426	467	putstr("done.\nBooting the kernel.\n");
968de4f0	468	return;
1da177e4	469	}