[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"
#include "../string.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 memcpy

/*
 * Use a normal definition of memset() 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 memset
#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 */

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

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(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 (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 __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);
	}
}

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

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

#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 + output_len;

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

	free(phdrs);
}

asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap,
				  unsigned char *input_data,
				  unsigned long input_len,
				  unsigned char *output,
				  unsigned long output_len,
				  unsigned long run_size)
{
	unsigned char *output_orig = output;

	real_mode = rmode;

	/* Clear it for solely in-kernel use */
	real_mode->hdr.loadflags &= ~KASLR_FLAG;

	sanitize_boot_params(real_mode);

	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();
	debug_putstr("early console in decompress_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(run_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_kernel_location(real_mode, input_data, input_len, output,
					output_len > run_size ? output_len
							      : run_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, 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 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"
820e8fec	13	#include "../string.h"
968de4f0 EB	14
	15	/* WARNING!!
	16	* This code is compiled with -fPIC and it is relocated dynamically
	17	* at run time, but no relocation processing is performed.
	18	* This means that it is not safe to place pointers in static structures.
	19	*/
	20
	21	/*
	22	* Getting to provable safe in place decompression is hard.
27b46d76	23	* Worst case behaviours need to be analyzed.
968de4f0 EB	24	* Background information:
	25	*
	26	* The file layout is:
	27	* magic[2]
	28	* method[1]
	29	* flags[1]
	30	* timestamp[4]
	31	* extraflags[1]
	32	* os[1]
	33	* compressed data blocks[N]
	34	* crc[4] orig_len[4]
	35	*
	36	* resulting in 18 bytes of non compressed data overhead.
	37	*
	38	* Files divided into blocks
	39	* 1 bit (last block flag)
	40	* 2 bits (block type)
	41	*
1180e01d IM	42	* 1 block occurs every 32K -1 bytes or when there 50% compression
1180e01d IM	43	* has been achieved. The smallest block type encoding is always used.
968de4f0 EB	44	*
	45	* stored:
	46	* 32 bits length in bytes.
	47	*
	48	* fixed:
	49	* magic fixed tree.
	50	* symbols.
	51	*
	52	* dynamic:
	53	* dynamic tree encoding.
	54	* symbols.
	55	*
	56	*
	57	* The buffer for decompression in place is the length of the
	58	* uncompressed data, plus a small amount extra to keep the algorithm safe.
	59	* The compressed data is placed at the end of the buffer. The output
	60	* pointer is placed at the start of the buffer and the input pointer
	61	* is placed where the compressed data starts. Problems will occur
	62	* when the output pointer overruns the input pointer.
	63	*
	64	* The output pointer can only overrun the input pointer if the input
	65	* pointer is moving faster than the output pointer. A condition only
	66	* triggered by data whose compressed form is larger than the uncompressed
	67	* form.
	68	*
	69	* The worst case at the block level is a growth of the compressed data
	70	* of 5 bytes per 32767 bytes.
	71	*
	72	* The worst case internal to a compressed block is very hard to figure.
	73	* The worst case can at least be boundined by having one bit that represents
	74	* 32764 bytes and then all of the rest of the bytes representing the very
	75	* very last byte.
	76	*
	77	* All of which is enough to compute an amount of extra data that is required
	78	* to be safe. To avoid problems at the block level allocating 5 extra bytes
1180e01d IM	79	* per 32767 bytes of data is sufficient. To avoind problems internal to a
	80	* block adding an extra 32767 bytes (the worst case uncompressed block size)
	81	* is sufficient, to ensure that in the worst case the decompressed data for
968de4f0 EB	82	* block will stop the byte before the compressed data for a block begins.
	83	* To avoid problems with the compressed data's meta information an extra 18
	84	* bytes are needed. Leading to the formula:
	85	*
	86	* extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
	87	*
	88	* Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
	89	* Adding 32768 instead of 32767 just makes for round numbers.
	90	* Adding the decompressor_size is necessary as it musht live after all
	91	* of the data as well. Last I measured the decompressor is about 14K.
27b46d76	92	* 10K of actual data and 4K of bss.
968de4f0 EB	93	*
968de4f0 EB	94	*/
1da177e4 LT	95
	96	/*
	97	* gzip declarations
	98	*/
1180e01d	99	#define STATIC static
1da177e4	100
1da177e4	101	#undef memcpy
04999550 VG	102
	103	/*
	104	* Use a normal definition of memset() from string.c. There are already
	105	* included header files which expect a definition of memset() and by
	106	* the time we define memset macro, it is too late.
	107	*/
	108	#undef memset
1180e01d	109	#define memzero(s, n) memset((s), 0, (n))
1da177e4	110
1da177e4	111
1da177e4	112	static void error(char *m);
fd77c7ca	113
1da177e4 LT	114	/*
	115	* This is set up by the setup-routine at boot-time
	116	*/
8fee13a4	117	struct boot_params real_mode; / Pointer to real-mode data */
1da177e4	118
82fa9637 KC	119	memptr free_mem_ptr;
82fa9637 KC	120	memptr free_mem_end_ptr;
1da177e4	121
03056c88	122	static char *vidmem;
1da177e4 LT	123	static int vidport;
	124	static int lines, cols;
	125
ae03c499 AK	126	#ifdef CONFIG_KERNEL_GZIP
	127	#include "../../../../lib/decompress_inflate.c"
	128	#endif
	129
	130	#ifdef CONFIG_KERNEL_BZIP2
	131	#include "../../../../lib/decompress_bunzip2.c"
	132	#endif
	133
	134	#ifdef CONFIG_KERNEL_LZMA
	135	#include "../../../../lib/decompress_unlzma.c"
	136	#endif
1da177e4	137
30314804 LC	138	#ifdef CONFIG_KERNEL_XZ
	139	#include "../../../../lib/decompress_unxz.c"
	140	#endif
	141
13510997 AT	142	#ifdef CONFIG_KERNEL_LZO
	143	#include "../../../../lib/decompress_unlzo.c"
	144	#endif
	145
f9b493ac KL	146	#ifdef CONFIG_KERNEL_LZ4
	147	#include "../../../../lib/decompress_unlz4.c"
	148	#endif
	149
1da177e4 LT	150	static void scroll(void)
	151	{
	152	int i;
	153
fd77c7ca PC	154	memcpy(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
fd77c7ca PC	155	for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
1da177e4 LT	156	vidmem[i] = ' ';
	157	}
	158
8fee13a4 YL	159	#define XMTRDY 0x20
	160
	161	#define TXR 0 /* Transmit register (WRITE) */
	162	#define LSR 5 /* Line Status */
	163	static void serial_putchar(int ch)
	164	{
	165	unsigned timeout = 0xffff;
	166
	167	while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
	168	cpu_relax();
	169
	170	outb(ch, early_serial_base + TXR);
	171	}
	172
7aac3015	173	void __putstr(const char *s)
1da177e4	174	{
fd77c7ca	175	int x, y, pos;
1da177e4 LT	176	char c;
1da177e4 LT	177
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
79063a7c KC	223	void __puthex(unsigned long value)
	224	{
	225	char alpha[2] = "0";
	226	int bits;
	227
	228	for (bits = sizeof(value) * 8 - 4; bits >= 0; bits -= 4) {
	229	unsigned long digit = (value >> bits) & 0xf;
	230
	231	if (digit < 0xA)
	232	alpha[0] = '0' + digit;
	233	else
	234	alpha[0] = 'a' + (digit - 0xA);
	235
	236	__putstr(alpha);
	237	}
	238	}
	239
1da177e4 LT	240	static void error(char *x)
1da177e4 LT	241	{
cb454fe1 JM	242	error_putstr("\n\n");
	243	error_putstr(x);
	244	error_putstr("\n\n -- System halted");
1da177e4	245
ff3cf856 IM	246	while (1)
ff3cf856 IM	247	asm("hlt");
1da177e4 LT	248	}
1da177e4 LT	249
a0215061 KC	250	#if CONFIG_X86_NEED_RELOCS
	251	static void handle_relocations(void *output, unsigned long output_len)
	252	{
	253	int *reloc;
	254	unsigned long delta, map, ptr;
	255	unsigned long min_addr = (unsigned long)output;
	256	unsigned long max_addr = min_addr + output_len;
	257
	258	/*
	259	* Calculate the delta between where vmlinux was linked to load
	260	* and where it was actually loaded.
	261	*/
	262	delta = min_addr - LOAD_PHYSICAL_ADDR;
	263	if (!delta) {
	264	debug_putstr("No relocation needed... ");
	265	return;
	266	}
	267	debug_putstr("Performing relocations... ");
	268
	269	/*
	270	* The kernel contains a table of relocation addresses. Those
	271	* addresses have the final load address of the kernel in virtual
	272	* memory. We are currently working in the self map. So we need to
	273	* create an adjustment for kernel memory addresses to the self map.
	274	* This will involve subtracting out the base address of the kernel.
	275	*/
	276	map = delta - __START_KERNEL_map;
	277
	278	/*
	279	* Process relocations: 32 bit relocations first then 64 bit after.
6d24c5f7	280	* Three sets of binary relocations are added to the end of the kernel
a0215061 KC	281	* before compression. Each relocation table entry is the kernel
	282	* address of the location which needs to be updated stored as a
	283	* 32-bit value which is sign extended to 64 bits.
	284	*
	285	* Format is:
	286	*
	287	* kernel bits...
	288	* 0 - zero terminator for 64 bit relocations
	289	* 64 bit relocation repeated
6d24c5f7 JB	290	* 0 - zero terminator for inverse 32 bit relocations
6d24c5f7 JB	291	* 32 bit inverse relocation repeated
a0215061 KC	292	* 0 - zero terminator for 32 bit relocations
	293	* 32 bit relocation repeated
	294	*
	295	* So we work backwards from the end of the decompressed image.
	296	*/
	297	for (reloc = output + output_len - sizeof(reloc); reloc; reloc--) {
	298	int extended = *reloc;
	299	extended += map;
	300
	301	ptr = (unsigned long)extended;
	302	if (ptr < min_addr \|\| ptr > max_addr)
	303	error("32-bit relocation outside of kernel!\n");
	304
	305	(uint32_t )ptr += delta;
	306	}
	307	#ifdef CONFIG_X86_64
6d24c5f7 JB	308	while (*--reloc) {
	309	long extended = *reloc;
	310	extended += map;
	311
	312	ptr = (unsigned long)extended;
	313	if (ptr < min_addr \|\| ptr > max_addr)
	314	error("inverse 32-bit relocation outside of kernel!\n");
	315
	316	(int32_t )ptr -= delta;
	317	}
a0215061 KC	318	for (reloc--; *reloc; reloc--) {
	319	long extended = *reloc;
	320	extended += map;
	321
	322	ptr = (unsigned long)extended;
	323	if (ptr < min_addr \|\| ptr > max_addr)
	324	error("64-bit relocation outside of kernel!\n");
	325
	326	(uint64_t )ptr += delta;
	327	}
	328	#endif
	329	}
	330	#else
	331	static inline void handle_relocations(void *output, unsigned long output_len)
	332	{ }
	333	#endif
	334
099e1377 IC	335	static void parse_elf(void *output)
	336	{
	337	#ifdef CONFIG_X86_64
	338	Elf64_Ehdr ehdr;
	339	Elf64_Phdr phdrs, phdr;
	340	#else
	341	Elf32_Ehdr ehdr;
	342	Elf32_Phdr phdrs, phdr;
	343	#endif
	344	void *dest;
	345	int i;
	346
	347	memcpy(&ehdr, output, sizeof(ehdr));
fd77c7ca	348	if (ehdr.e_ident[EI_MAG0] != ELFMAG0 \|\|
099e1377 IC	349	ehdr.e_ident[EI_MAG1] != ELFMAG1 \|\|
099e1377 IC	350	ehdr.e_ident[EI_MAG2] != ELFMAG2 \|\|
fd77c7ca	351	ehdr.e_ident[EI_MAG3] != ELFMAG3) {
099e1377 IC	352	error("Kernel is not a valid ELF file");
	353	return;
	354	}
	355
e605a425	356	debug_putstr("Parsing ELF... ");
099e1377 IC	357
	358	phdrs = malloc(sizeof(phdrs) ehdr.e_phnum);
	359	if (!phdrs)
	360	error("Failed to allocate space for phdrs");
	361
	362	memcpy(phdrs, output + ehdr.e_phoff, sizeof(phdrs) ehdr.e_phnum);
	363
fd77c7ca	364	for (i = 0; i < ehdr.e_phnum; i++) {
099e1377 IC	365	phdr = &phdrs[i];
	366
	367	switch (phdr->p_type) {
	368	case PT_LOAD:
	369	#ifdef CONFIG_RELOCATABLE
	370	dest = output;
	371	dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
	372	#else
fd77c7ca	373	dest = (void *)(phdr->p_paddr);
099e1377 IC	374	#endif
	375	memcpy(dest,
	376	output + phdr->p_offset,
	377	phdr->p_filesz);
	378	break;
	379	default: /* Ignore other PT_* */ break;
	380	}
	381	}
5067cf53 JJ	382
5067cf53 JJ	383	free(phdrs);
099e1377 IC	384	}
099e1377 IC	385
2605fc21	386	asmlinkage __visible void decompress_kernel(void rmode, memptr heap,
1180e01d IM	387	unsigned char *input_data,
1180e01d IM	388	unsigned long input_len,
a0215061	389	unsigned char *output,
e6023367 JM	390	unsigned long output_len,
e6023367 JM	391	unsigned long run_size)
1da177e4	392	{
f285f4a2 KC	393	unsigned char *output_orig = output;
f285f4a2 KC	394
1da177e4 LT	395	real_mode = rmode;
1da177e4 LT	396
78cac48c BP	397	/* Clear it for solely in-kernel use */
	398	real_mode->hdr.loadflags &= ~KASLR_FLAG;
	399
5dcd14ec PA	400	sanitize_boot_params(real_mode);
5dcd14ec PA	401
23968f71	402	if (real_mode->screen_info.orig_video_mode == 7) {
1da177e4 LT	403	vidmem = (char *) 0xb0000;
	404	vidport = 0x3b4;
	405	} else {
	406	vidmem = (char *) 0xb8000;
	407	vidport = 0x3d4;
	408	}
	409
23968f71 KH	410	lines = real_mode->screen_info.orig_video_lines;
23968f71 KH	411	cols = real_mode->screen_info.orig_video_cols;
1da177e4	412
8fee13a4	413	console_init();
e605a425	414	debug_putstr("early console in decompress_kernel\n");
8fee13a4	415
4c83d653	416	free_mem_ptr = heap; /* Heap */
7c539764	417	free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
968de4f0	418
79063a7c KC	419	/* Report initial kernel position details. */
	420	debug_putaddr(input_data);
	421	debug_putaddr(input_len);
	422	debug_putaddr(output);
	423	debug_putaddr(output_len);
	424	debug_putaddr(run_size);
	425
e6023367 JM	426	/*
	427	* The memory hole needed for the kernel is the larger of either
	428	* the entire decompressed kernel plus relocation table, or the
	429	* entire decompressed kernel plus .bss and .brk sections.
	430	*/
78cac48c	431	output = choose_kernel_location(real_mode, input_data, input_len, output,
e6023367 JM	432	output_len > run_size ? output_len
e6023367 JM	433	: run_size);
8ab3820f KC	434
8ab3820f KC	435	/* Validate memory location choices. */
7ed42a28 PA	436	if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
7ed42a28 PA	437	error("Destination address inappropriately aligned");
778cb929	438	#ifdef CONFIG_X86_64
7ed42a28	439	if (heap > 0x3fffffffffffUL)
778cb929 IC	440	error("Destination address too large");
778cb929 IC	441	#else
147dd561	442	if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
968de4f0	443	error("Destination address too large");
7ed42a28	444	#endif
968de4f0	445	#ifndef CONFIG_RELOCATABLE
7ed42a28	446	if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
968de4f0 EB	447	error("Wrong destination address");
968de4f0 EB	448	#endif
1da177e4	449
e605a425	450	debug_putstr("\nDecompressing Linux... ");
ae03c499	451	decompress(input_data, input_len, NULL, NULL, output, NULL, error);
099e1377	452	parse_elf(output);
f285f4a2 KC	453	/*
	454	* 32-bit always performs relocations. 64-bit relocations are only
	455	* needed if kASLR has chosen a different load address.
	456	*/
	457	if (!IS_ENABLED(CONFIG_X86_64) \|\| output != output_orig)
	458	handle_relocations(output, output_len);
e605a425	459	debug_putstr("done.\nBooting the kernel.\n");
8ab3820f	460	return output;
1da177e4	461	}