[linux-2.6-block.git] / arch / x86 / boot / compressed / misc.c

/*
 * misc.c
 *
 * This is a collection of several routines used to extract the kernel
 * which includes KASLR relocation, decompression, ELF parsing, and
 * relocation processing. Additionally included are the screen and serial
 * output functions and related debugging support functions.
 *
 * 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"
#include "error.h"
#include "../string.h"
#include "../voffset.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.
 */

/* Macros used by the included decompressor code below. */
#define STATIC		static

/*
 * Use normal definitions of mem*() from string.c. There are already
 * included header files which expect a definition of memset() and by
 * the time we define memset macro, it is too late.
 */
#undef memcpy
#undef memset
#define memzero(s, n)	memset((s), 0, (n))
#define memmove		memmove

/* Functions used by the included decompressor code below. */
void *memmove(void *dest, const void *src, size_t n);

/*
 * This is set up by the setup-routine at boot-time
 */
struct boot_params *boot_params;

memptr free_mem_ptr;
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_XZ
#include "../../../../lib/decompress_unxz.c"
#endif

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

#ifdef CONFIG_KERNEL_LZ4
#include "../../../../lib/decompress_unlz4.c"
#endif
/*
 * NOTE: When adding a new decompressor, please update the analysis in
 * ../header.S.
 */

static void scroll(void)
{
	int i;

	memmove(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(const char *s)
{
	int x, y, pos;
	char c;

	if (early_serial_base) {
		const char *str = s;
		while (*str) {
			if (*str == '\n')
				serial_putchar('\r');
			serial_putchar(*str++);
		}
	}

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

	x = boot_params->screen_info.orig_x;
	y = boot_params->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--;
				}
			}
		}
	}

	boot_params->screen_info.orig_x = x;
	boot_params->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 __puthex(unsigned long value)
{
	char alpha[2] = "0";
	int bits;

	for (bits = sizeof(value) * 8 - 4; bits >= 0; bits -= 4) {
		unsigned long digit = (value >> bits) & 0xf;

		if (digit < 0xA)
			alpha[0] = '0' + digit;
		else
			alpha[0] = 'a' + (digit - 0xA);

		__putstr(alpha);
	}
}

#if CONFIG_X86_NEED_RELOCS
static void handle_relocations(void *output, unsigned long output_len)
{
	int *reloc;
	unsigned long delta, map, ptr;
	unsigned long min_addr = (unsigned long)output;
	unsigned long max_addr = min_addr + (VO___bss_start - VO__text);

	/*
	 * Calculate the delta between where vmlinux was linked to load
	 * and where it was actually loaded.
	 */
	delta = min_addr - LOAD_PHYSICAL_ADDR;
	if (!delta) {
		debug_putstr("No relocation needed... ");
		return;
	}
	debug_putstr("Performing relocations... ");

	/*
	 * The kernel contains a table of relocation addresses. Those
	 * addresses have the final load address of the kernel in virtual
	 * memory. We are currently working in the self map. So we need to
	 * create an adjustment for kernel memory addresses to the self map.
	 * This will involve subtracting out the base address of the kernel.
	 */
	map = delta - __START_KERNEL_map;

	/*
	 * Process relocations: 32 bit relocations first then 64 bit after.
	 * Three sets of binary relocations are added to the end of the kernel
	 * before compression. Each relocation table entry is the kernel
	 * address of the location which needs to be updated stored as a
	 * 32-bit value which is sign extended to 64 bits.
	 *
	 * Format is:
	 *
	 * kernel bits...
	 * 0 - zero terminator for 64 bit relocations
	 * 64 bit relocation repeated
	 * 0 - zero terminator for inverse 32 bit relocations
	 * 32 bit inverse relocation repeated
	 * 0 - zero terminator for 32 bit relocations
	 * 32 bit relocation repeated
	 *
	 * So we work backwards from the end of the decompressed image.
	 */
	for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
		long extended = *reloc;
		extended += map;

		ptr = (unsigned long)extended;
		if (ptr < min_addr || ptr > max_addr)
			error("32-bit relocation outside of kernel!\n");

		*(uint32_t *)ptr += delta;
	}
#ifdef CONFIG_X86_64
	while (*--reloc) {
		long extended = *reloc;
		extended += map;

		ptr = (unsigned long)extended;
		if (ptr < min_addr || ptr > max_addr)
			error("inverse 32-bit relocation outside of kernel!\n");

		*(int32_t *)ptr -= delta;
	}
	for (reloc--; *reloc; reloc--) {
		long extended = *reloc;
		extended += map;

		ptr = (unsigned long)extended;
		if (ptr < min_addr || ptr > max_addr)
			error("64-bit relocation outside of kernel!\n");

		*(uint64_t *)ptr += delta;
	}
#endif
}
#else
static inline void handle_relocations(void *output, unsigned long output_len)
{ }
#endif

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;
	}

	debug_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
			memmove(dest, output + phdr->p_offset, phdr->p_filesz);
			break;
		default: /* Ignore other PT_* */ break;
		}
	}

	free(phdrs);
}

/*
 * The compressed kernel image (ZO), has been moved so that its position
 * is against the end of the buffer used to hold the uncompressed kernel
 * image (VO) and the execution environment (.bss, .brk), which makes sure
 * there is room to do the in-place decompression. (See header.S for the
 * calculations.)
 *
 *                             |-----compressed kernel image------|
 *                             V                                  V
 * 0                       extract_offset                      +INIT_SIZE
 * |-----------|---------------|-------------------------|--------|
 *             |               |                         |        |
 *           VO__text      startup_32 of ZO          VO__end    ZO__end
 *             ^                                         ^
 *             |-------uncompressed kernel image---------|
 *
 */
asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
				  unsigned char *input_data,
				  unsigned long input_len,
				  unsigned char *output,
				  unsigned long output_len)
{
	const unsigned long kernel_total_size = VO__end - VO__text;
	unsigned char *output_orig = output;

	/* Retain x86 boot parameters pointer passed from startup_32/64. */
	boot_params = rmode;

	/* Clear flags intended for solely in-kernel use. */
	boot_params->hdr.loadflags &= ~KASLR_FLAG;

	sanitize_boot_params(boot_params);

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

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

	console_init();
	debug_putstr("early console in extract_kernel\n");

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

	/* Report initial kernel position details. */
	debug_putaddr(input_data);
	debug_putaddr(input_len);
	debug_putaddr(output);
	debug_putaddr(output_len);
	debug_putaddr(kernel_total_size);

	/*
	 * The memory hole needed for the kernel is the larger of either
	 * the entire decompressed kernel plus relocation table, or the
	 * entire decompressed kernel plus .bss and .brk sections.
	 */
	output = choose_random_location((unsigned long)input_data, input_len,
					(unsigned long)output,
					max(output_len, kernel_total_size));

	/* Validate memory location choices. */
	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-(128<<20)-1) & 0x7fffffff))
		error("Destination address too large");
#endif
#ifndef CONFIG_RELOCATABLE
	if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
		error("Wrong destination address");
#endif

	debug_putstr("\nDecompressing Linux... ");
	__decompress(input_data, input_len, NULL, NULL, output, output_len,
			NULL, error);
	parse_elf(output);
	/*
	 * 32-bit always performs relocations. 64-bit relocations are only
	 * needed if kASLR has chosen a different load address.
	 */
	if (!IS_ENABLED(CONFIG_X86_64) || output != output_orig)
		handle_relocations(output, output_len);
	debug_putstr("done.\nBooting the kernel.\n");
	return output;
}
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* misc.c
818a08f8	3	*
c0402881 KC	4	* This is a collection of several routines used to extract the kernel
	5	* which includes KASLR relocation, decompression, ELF parsing, and
	6	* relocation processing. Additionally included are the screen and serial
	7	* output functions and related debugging support functions.
1da177e4 LT	8	*
	9	* malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
	10	* puts by Nick Holloway 1993, better puts by Martin Mares 1995
	11	* High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
	12	*/
	13
8fee13a4	14	#include "misc.h"
dc425a6e	15	#include "error.h"
820e8fec	16	#include "../string.h"
67b66625	17	#include "../voffset.h"
968de4f0	18
968de4f0	19	/*
4252db10 BH	20	* WARNING!!
	21	* This code is compiled with -fPIC and it is relocated dynamically at
	22	* run time, but no relocation processing is performed. This means that
	23	* it is not safe to place pointers in static structures.
968de4f0	24	*/
1da177e4	25
1f208de3	26	/* Macros used by the included decompressor code below. */
1180e01d	27	#define STATIC static
1da177e4	28
04999550	29	/*
1f208de3	30	* Use normal definitions of mem*() from string.c. There are already
04999550 VG	31	* included header files which expect a definition of memset() and by
	32	* the time we define memset macro, it is too late.
	33	*/
1f208de3	34	#undef memcpy
04999550	35	#undef memset
1180e01d	36	#define memzero(s, n) memset((s), 0, (n))
81b785f3	37	#define memmove memmove
1da177e4	38
1f208de3	39	/* Functions used by the included decompressor code below. */
81b785f3	40	void memmove(void dest, const void *src, size_t n);
fd77c7ca	41
1da177e4 LT	42	/*
	43	* This is set up by the setup-routine at boot-time
	44	*/
6655e0aa	45	struct boot_params *boot_params;
1da177e4	46
82fa9637 KC	47	memptr free_mem_ptr;
82fa9637 KC	48	memptr free_mem_end_ptr;
1da177e4	49
03056c88	50	static char *vidmem;
1da177e4 LT	51	static int vidport;
	52	static int lines, cols;
	53
ae03c499 AK	54	#ifdef CONFIG_KERNEL_GZIP
	55	#include "../../../../lib/decompress_inflate.c"
	56	#endif
	57
	58	#ifdef CONFIG_KERNEL_BZIP2
	59	#include "../../../../lib/decompress_bunzip2.c"
	60	#endif
	61
	62	#ifdef CONFIG_KERNEL_LZMA
	63	#include "../../../../lib/decompress_unlzma.c"
	64	#endif
1da177e4	65
30314804 LC	66	#ifdef CONFIG_KERNEL_XZ
	67	#include "../../../../lib/decompress_unxz.c"
	68	#endif
	69
13510997 AT	70	#ifdef CONFIG_KERNEL_LZO
	71	#include "../../../../lib/decompress_unlzo.c"
	72	#endif
	73
f9b493ac KL	74	#ifdef CONFIG_KERNEL_LZ4
	75	#include "../../../../lib/decompress_unlz4.c"
	76	#endif
4252db10 BH	77	/*
	78	* NOTE: When adding a new decompressor, please update the analysis in
	79	* ../header.S.
	80	*/
f9b493ac	81
1da177e4 LT	82	static void scroll(void)
	83	{
	84	int i;
	85
81b785f3	86	memmove(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
fd77c7ca	87	for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
1da177e4 LT	88	vidmem[i] = ' ';
	89	}
	90
8fee13a4 YL	91	#define XMTRDY 0x20
	92
	93	#define TXR 0 /* Transmit register (WRITE) */
	94	#define LSR 5 /* Line Status */
	95	static void serial_putchar(int ch)
	96	{
	97	unsigned timeout = 0xffff;
	98
	99	while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
	100	cpu_relax();
	101
	102	outb(ch, early_serial_base + TXR);
	103	}
	104
7aac3015	105	void __putstr(const char *s)
1da177e4	106	{
fd77c7ca	107	int x, y, pos;
1da177e4 LT	108	char c;
1da177e4 LT	109
8fee13a4 YL	110	if (early_serial_base) {
	111	const char *str = s;
	112	while (*str) {
	113	if (*str == '\n')
	114	serial_putchar('\r');
	115	serial_putchar(*str++);
	116	}
	117	}
6bcb13b3	118
6655e0aa	119	if (boot_params->screen_info.orig_video_mode == 0 &&
23968f71	120	lines == 0 && cols == 0)
a24e7851 RR	121	return;
a24e7851 RR	122
6655e0aa KC	123	x = boot_params->screen_info.orig_x;
6655e0aa KC	124	y = boot_params->screen_info.orig_y;
1da177e4	125
fd77c7ca PC	126	while ((c = *s++) != '\0') {
fd77c7ca PC	127	if (c == '\n') {
1da177e4	128	x = 0;
fd77c7ca	129	if (++y >= lines) {
1da177e4 LT	130	scroll();
	131	y--;
	132	}
	133	} else {
020878ac	134	vidmem[(x + cols * y) * 2] = c;
fd77c7ca	135	if (++x >= cols) {
1da177e4	136	x = 0;
fd77c7ca	137	if (++y >= lines) {
1da177e4 LT	138	scroll();
	139	y--;
	140	}
	141	}
	142	}
	143	}
	144
6655e0aa KC	145	boot_params->screen_info.orig_x = x;
6655e0aa KC	146	boot_params->screen_info.orig_y = y;
1da177e4 LT	147
1da177e4 LT	148	pos = (x + cols * y) * 2; /* Update cursor position */
b02aae9c RH	149	outb(14, vidport);
	150	outb(0xff & (pos >> 9), vidport+1);
	151	outb(15, vidport);
	152	outb(0xff & (pos >> 1), vidport+1);
1da177e4 LT	153	}
1da177e4 LT	154
79063a7c KC	155	void __puthex(unsigned long value)
	156	{
	157	char alpha[2] = "0";
	158	int bits;
	159
	160	for (bits = sizeof(value) * 8 - 4; bits >= 0; bits -= 4) {
	161	unsigned long digit = (value >> bits) & 0xf;
	162
	163	if (digit < 0xA)
	164	alpha[0] = '0' + digit;
	165	else
	166	alpha[0] = 'a' + (digit - 0xA);
	167
	168	__putstr(alpha);
	169	}
	170	}
	171
a0215061 KC	172	#if CONFIG_X86_NEED_RELOCS
	173	static void handle_relocations(void *output, unsigned long output_len)
	174	{
	175	int *reloc;
	176	unsigned long delta, map, ptr;
	177	unsigned long min_addr = (unsigned long)output;
4abf061b	178	unsigned long max_addr = min_addr + (VO___bss_start - VO__text);
a0215061 KC	179
	180	/*
	181	* Calculate the delta between where vmlinux was linked to load
	182	* and where it was actually loaded.
	183	*/
	184	delta = min_addr - LOAD_PHYSICAL_ADDR;
	185	if (!delta) {
	186	debug_putstr("No relocation needed... ");
	187	return;
	188	}
	189	debug_putstr("Performing relocations... ");
	190
	191	/*
	192	* The kernel contains a table of relocation addresses. Those
	193	* addresses have the final load address of the kernel in virtual
	194	* memory. We are currently working in the self map. So we need to
	195	* create an adjustment for kernel memory addresses to the self map.
	196	* This will involve subtracting out the base address of the kernel.
	197	*/
	198	map = delta - __START_KERNEL_map;
	199
	200	/*
	201	* Process relocations: 32 bit relocations first then 64 bit after.
6d24c5f7	202	* Three sets of binary relocations are added to the end of the kernel
a0215061 KC	203	* before compression. Each relocation table entry is the kernel
	204	* address of the location which needs to be updated stored as a
	205	* 32-bit value which is sign extended to 64 bits.
	206	*
	207	* Format is:
	208	*
	209	* kernel bits...
	210	* 0 - zero terminator for 64 bit relocations
	211	* 64 bit relocation repeated
6d24c5f7 JB	212	* 0 - zero terminator for inverse 32 bit relocations
6d24c5f7 JB	213	* 32 bit inverse relocation repeated
a0215061 KC	214	* 0 - zero terminator for 32 bit relocations
	215	* 32 bit relocation repeated
	216	*
	217	* So we work backwards from the end of the decompressed image.
	218	*/
	219	for (reloc = output + output_len - sizeof(reloc); reloc; reloc--) {
6f9af75f	220	long extended = *reloc;
a0215061 KC	221	extended += map;
	222
	223	ptr = (unsigned long)extended;
	224	if (ptr < min_addr \|\| ptr > max_addr)
	225	error("32-bit relocation outside of kernel!\n");
	226
	227	(uint32_t )ptr += delta;
	228	}
	229	#ifdef CONFIG_X86_64
6d24c5f7 JB	230	while (*--reloc) {
	231	long extended = *reloc;
	232	extended += map;
	233
	234	ptr = (unsigned long)extended;
	235	if (ptr < min_addr \|\| ptr > max_addr)
	236	error("inverse 32-bit relocation outside of kernel!\n");
	237
	238	(int32_t )ptr -= delta;
	239	}
a0215061 KC	240	for (reloc--; *reloc; reloc--) {
	241	long extended = *reloc;
	242	extended += map;
	243
	244	ptr = (unsigned long)extended;
	245	if (ptr < min_addr \|\| ptr > max_addr)
	246	error("64-bit relocation outside of kernel!\n");
	247
	248	(uint64_t )ptr += delta;
	249	}
	250	#endif
	251	}
	252	#else
	253	static inline void handle_relocations(void *output, unsigned long output_len)
	254	{ }
	255	#endif
	256
099e1377 IC	257	static void parse_elf(void *output)
	258	{
	259	#ifdef CONFIG_X86_64
	260	Elf64_Ehdr ehdr;
	261	Elf64_Phdr phdrs, phdr;
	262	#else
	263	Elf32_Ehdr ehdr;
	264	Elf32_Phdr phdrs, phdr;
	265	#endif
	266	void *dest;
	267	int i;
	268
	269	memcpy(&ehdr, output, sizeof(ehdr));
fd77c7ca	270	if (ehdr.e_ident[EI_MAG0] != ELFMAG0 \|\|
099e1377 IC	271	ehdr.e_ident[EI_MAG1] != ELFMAG1 \|\|
099e1377 IC	272	ehdr.e_ident[EI_MAG2] != ELFMAG2 \|\|
fd77c7ca	273	ehdr.e_ident[EI_MAG3] != ELFMAG3) {
099e1377 IC	274	error("Kernel is not a valid ELF file");
	275	return;
	276	}
	277
e605a425	278	debug_putstr("Parsing ELF... ");
099e1377 IC	279
	280	phdrs = malloc(sizeof(phdrs) ehdr.e_phnum);
	281	if (!phdrs)
	282	error("Failed to allocate space for phdrs");
	283
	284	memcpy(phdrs, output + ehdr.e_phoff, sizeof(phdrs) ehdr.e_phnum);
	285
fd77c7ca	286	for (i = 0; i < ehdr.e_phnum; i++) {
099e1377 IC	287	phdr = &phdrs[i];
	288
	289	switch (phdr->p_type) {
	290	case PT_LOAD:
	291	#ifdef CONFIG_RELOCATABLE
	292	dest = output;
	293	dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
	294	#else
fd77c7ca	295	dest = (void *)(phdr->p_paddr);
099e1377	296	#endif
81b785f3	297	memmove(dest, output + phdr->p_offset, phdr->p_filesz);
099e1377 IC	298	break;
	299	default: /* Ignore other PT_* */ break;
	300	}
	301	}
5067cf53 JJ	302
5067cf53 JJ	303	free(phdrs);
099e1377 IC	304	}
099e1377 IC	305
974f221c YL	306	/*
	307	* The compressed kernel image (ZO), has been moved so that its position
	308	* is against the end of the buffer used to hold the uncompressed kernel
	309	* image (VO) and the execution environment (.bss, .brk), which makes sure
	310	* there is room to do the in-place decompression. (See header.S for the
	311	* calculations.)
	312	*
	313	* \|-----compressed kernel image------\|
	314	* V V
	315	* 0 extract_offset +INIT_SIZE
	316	* \|-----------\|---------------\|-------------------------\|--------\|
	317	* \| \| \| \|
	318	* VO__text startup_32 of ZO VO__end ZO__end
	319	* ^ ^
	320	* \|-------uncompressed kernel image---------\|
	321	*
	322	*/
c0402881	323	asmlinkage __visible void extract_kernel(void rmode, memptr heap,
1180e01d IM	324	unsigned char *input_data,
1180e01d IM	325	unsigned long input_len,
a0215061	326	unsigned char *output,
4d2d5424	327	unsigned long output_len)
1da177e4	328	{
4d2d5424	329	const unsigned long kernel_total_size = VO__end - VO__text;
f285f4a2 KC	330	unsigned char *output_orig = output;
f285f4a2 KC	331
6655e0aa KC	332	/* Retain x86 boot parameters pointer passed from startup_32/64. */
6655e0aa KC	333	boot_params = rmode;
1da177e4	334
6655e0aa KC	335	/* Clear flags intended for solely in-kernel use. */
6655e0aa KC	336	boot_params->hdr.loadflags &= ~KASLR_FLAG;
78cac48c	337
6655e0aa	338	sanitize_boot_params(boot_params);
5dcd14ec	339
6655e0aa	340	if (boot_params->screen_info.orig_video_mode == 7) {
1da177e4 LT	341	vidmem = (char *) 0xb0000;
	342	vidport = 0x3b4;
	343	} else {
	344	vidmem = (char *) 0xb8000;
	345	vidport = 0x3d4;
	346	}
	347
6655e0aa KC	348	lines = boot_params->screen_info.orig_video_lines;
6655e0aa KC	349	cols = boot_params->screen_info.orig_video_cols;
1da177e4	350
8fee13a4	351	console_init();
c0402881	352	debug_putstr("early console in extract_kernel\n");
8fee13a4	353
4c83d653	354	free_mem_ptr = heap; /* Heap */
7c539764	355	free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
968de4f0	356
79063a7c KC	357	/* Report initial kernel position details. */
	358	debug_putaddr(input_data);
	359	debug_putaddr(input_len);
	360	debug_putaddr(output);
	361	debug_putaddr(output_len);
4d2d5424	362	debug_putaddr(kernel_total_size);
79063a7c	363
e6023367 JM	364	/*
	365	* The memory hole needed for the kernel is the larger of either
	366	* the entire decompressed kernel plus relocation table, or the
	367	* entire decompressed kernel plus .bss and .brk sections.
	368	*/
549f90db BP	369	output = choose_random_location((unsigned long)input_data, input_len,
549f90db BP	370	(unsigned long)output,
4d2d5424	371	max(output_len, kernel_total_size));
8ab3820f KC	372
8ab3820f KC	373	/* Validate memory location choices. */
7ed42a28 PA	374	if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
7ed42a28 PA	375	error("Destination address inappropriately aligned");
778cb929	376	#ifdef CONFIG_X86_64
7ed42a28	377	if (heap > 0x3fffffffffffUL)
778cb929 IC	378	error("Destination address too large");
778cb929 IC	379	#else
147dd561	380	if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
968de4f0	381	error("Destination address too large");
7ed42a28	382	#endif
968de4f0	383	#ifndef CONFIG_RELOCATABLE
7ed42a28	384	if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
968de4f0 EB	385	error("Wrong destination address");
968de4f0 EB	386	#endif
1da177e4	387
e605a425	388	debug_putstr("\nDecompressing Linux... ");
2d3862d2 YL	389	__decompress(input_data, input_len, NULL, NULL, output, output_len,
2d3862d2 YL	390	NULL, error);
099e1377	391	parse_elf(output);
f285f4a2 KC	392	/*
	393	* 32-bit always performs relocations. 64-bit relocations are only
	394	* needed if kASLR has chosen a different load address.
	395	*/
	396	if (!IS_ENABLED(CONFIG_X86_64) \|\| output != output_orig)
	397	handle_relocations(output, output_len);
e605a425	398	debug_putstr("done.\nBooting the kernel.\n");
8ab3820f	399	return output;
1da177e4	400	}