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1/*
2 * misc.c
3 *
4 * This is a collection of several routines from gzip-1.0.3
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
12#include "misc.h"
13#include "../string.h"
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.
23 * Worst case behaviours need to be analyzed.
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 *
42 * 1 block occurs every 32K -1 bytes or when there 50% compression
43 * has been achieved. The smallest block type encoding is always used.
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
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
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.
92 * 10K of actual data and 4K of bss.
93 *
94 */
95
96/*
97 * gzip declarations
98 */
99#define STATIC static
100
101#undef memcpy
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
109#define memzero(s, n) memset((s), 0, (n))
110
111
112static void error(char *m);
113
114/*
115 * This is set up by the setup-routine at boot-time
116 */
117struct boot_params *real_mode; /* Pointer to real-mode data */
118
119memptr free_mem_ptr;
120memptr free_mem_end_ptr;
121
122static char *vidmem;
123static int vidport;
124static int lines, cols;
125
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
137
138#ifdef CONFIG_KERNEL_XZ
139#include "../../../../lib/decompress_unxz.c"
140#endif
141
142#ifdef CONFIG_KERNEL_LZO
143#include "../../../../lib/decompress_unlzo.c"
144#endif
145
146#ifdef CONFIG_KERNEL_LZ4
147#include "../../../../lib/decompress_unlz4.c"
148#endif
149
150static void scroll(void)
151{
152 int i;
153
154 memcpy(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
155 for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
156 vidmem[i] = ' ';
157}
158
159#define XMTRDY 0x20
160
161#define TXR 0 /* Transmit register (WRITE) */
162#define LSR 5 /* Line Status */
163static 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
173void __putstr(const char *s)
174{
175 int x, y, pos;
176 char c;
177
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 }
186
187 if (real_mode->screen_info.orig_video_mode == 0 &&
188 lines == 0 && cols == 0)
189 return;
190
191 x = real_mode->screen_info.orig_x;
192 y = real_mode->screen_info.orig_y;
193
194 while ((c = *s++) != '\0') {
195 if (c == '\n') {
196 x = 0;
197 if (++y >= lines) {
198 scroll();
199 y--;
200 }
201 } else {
202 vidmem[(x + cols * y) * 2] = c;
203 if (++x >= cols) {
204 x = 0;
205 if (++y >= lines) {
206 scroll();
207 y--;
208 }
209 }
210 }
211 }
212
213 real_mode->screen_info.orig_x = x;
214 real_mode->screen_info.orig_y = y;
215
216 pos = (x + cols * y) * 2; /* Update cursor position */
217 outb(14, vidport);
218 outb(0xff & (pos >> 9), vidport+1);
219 outb(15, vidport);
220 outb(0xff & (pos >> 1), vidport+1);
221}
222
223static void error(char *x)
224{
225 error_putstr("\n\n");
226 error_putstr(x);
227 error_putstr("\n\n -- System halted");
228
229 while (1)
230 asm("hlt");
231}
232
233#if CONFIG_X86_NEED_RELOCS
234static void handle_relocations(void *output, unsigned long output_len)
235{
236 int *reloc;
237 unsigned long delta, map, ptr;
238 unsigned long min_addr = (unsigned long)output;
239 unsigned long max_addr = min_addr + output_len;
240
241 /*
242 * Calculate the delta between where vmlinux was linked to load
243 * and where it was actually loaded.
244 */
245 delta = min_addr - LOAD_PHYSICAL_ADDR;
246 if (!delta) {
247 debug_putstr("No relocation needed... ");
248 return;
249 }
250 debug_putstr("Performing relocations... ");
251
252 /*
253 * The kernel contains a table of relocation addresses. Those
254 * addresses have the final load address of the kernel in virtual
255 * memory. We are currently working in the self map. So we need to
256 * create an adjustment for kernel memory addresses to the self map.
257 * This will involve subtracting out the base address of the kernel.
258 */
259 map = delta - __START_KERNEL_map;
260
261 /*
262 * Process relocations: 32 bit relocations first then 64 bit after.
263 * Two sets of binary relocations are added to the end of the kernel
264 * before compression. Each relocation table entry is the kernel
265 * address of the location which needs to be updated stored as a
266 * 32-bit value which is sign extended to 64 bits.
267 *
268 * Format is:
269 *
270 * kernel bits...
271 * 0 - zero terminator for 64 bit relocations
272 * 64 bit relocation repeated
273 * 0 - zero terminator for 32 bit relocations
274 * 32 bit relocation repeated
275 *
276 * So we work backwards from the end of the decompressed image.
277 */
278 for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
279 int extended = *reloc;
280 extended += map;
281
282 ptr = (unsigned long)extended;
283 if (ptr < min_addr || ptr > max_addr)
284 error("32-bit relocation outside of kernel!\n");
285
286 *(uint32_t *)ptr += delta;
287 }
288#ifdef CONFIG_X86_64
289 for (reloc--; *reloc; reloc--) {
290 long extended = *reloc;
291 extended += map;
292
293 ptr = (unsigned long)extended;
294 if (ptr < min_addr || ptr > max_addr)
295 error("64-bit relocation outside of kernel!\n");
296
297 *(uint64_t *)ptr += delta;
298 }
299#endif
300}
301#else
302static inline void handle_relocations(void *output, unsigned long output_len)
303{ }
304#endif
305
306static void parse_elf(void *output)
307{
308#ifdef CONFIG_X86_64
309 Elf64_Ehdr ehdr;
310 Elf64_Phdr *phdrs, *phdr;
311#else
312 Elf32_Ehdr ehdr;
313 Elf32_Phdr *phdrs, *phdr;
314#endif
315 void *dest;
316 int i;
317
318 memcpy(&ehdr, output, sizeof(ehdr));
319 if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
320 ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
321 ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
322 ehdr.e_ident[EI_MAG3] != ELFMAG3) {
323 error("Kernel is not a valid ELF file");
324 return;
325 }
326
327 debug_putstr("Parsing ELF... ");
328
329 phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
330 if (!phdrs)
331 error("Failed to allocate space for phdrs");
332
333 memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);
334
335 for (i = 0; i < ehdr.e_phnum; i++) {
336 phdr = &phdrs[i];
337
338 switch (phdr->p_type) {
339 case PT_LOAD:
340#ifdef CONFIG_RELOCATABLE
341 dest = output;
342 dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
343#else
344 dest = (void *)(phdr->p_paddr);
345#endif
346 memcpy(dest,
347 output + phdr->p_offset,
348 phdr->p_filesz);
349 break;
350 default: /* Ignore other PT_* */ break;
351 }
352 }
353
354 free(phdrs);
355}
356
357asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap,
358 unsigned char *input_data,
359 unsigned long input_len,
360 unsigned char *output,
361 unsigned long output_len)
362{
363 real_mode = rmode;
364
365 sanitize_boot_params(real_mode);
366
367 if (real_mode->screen_info.orig_video_mode == 7) {
368 vidmem = (char *) 0xb0000;
369 vidport = 0x3b4;
370 } else {
371 vidmem = (char *) 0xb8000;
372 vidport = 0x3d4;
373 }
374
375 lines = real_mode->screen_info.orig_video_lines;
376 cols = real_mode->screen_info.orig_video_cols;
377
378 console_init();
379 debug_putstr("early console in decompress_kernel\n");
380
381 free_mem_ptr = heap; /* Heap */
382 free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
383
384 output = choose_kernel_location(input_data, input_len,
385 output, output_len);
386
387 /* Validate memory location choices. */
388 if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
389 error("Destination address inappropriately aligned");
390#ifdef CONFIG_X86_64
391 if (heap > 0x3fffffffffffUL)
392 error("Destination address too large");
393#else
394 if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
395 error("Destination address too large");
396#endif
397#ifndef CONFIG_RELOCATABLE
398 if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
399 error("Wrong destination address");
400#endif
401
402 debug_putstr("\nDecompressing Linux... ");
403 decompress(input_data, input_len, NULL, NULL, output, NULL, error);
404 parse_elf(output);
405 handle_relocations(output, output_len);
406 debug_putstr("done.\nBooting the kernel.\n");
407 return output;
408}
1/*
2 * misc.c
3 *
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.
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
14#include "misc.h"
15#include "error.h"
16#include "../string.h"
17#include "../voffset.h"
18
19/*
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.
24 */
25
26/* Macros used by the included decompressor code below. */
27#define STATIC static
28
29/*
30 * Use normal definitions of mem*() from string.c. There are already
31 * included header files which expect a definition of memset() and by
32 * the time we define memset macro, it is too late.
33 */
34#undef memcpy
35#undef memset
36#define memzero(s, n) memset((s), 0, (n))
37#define memmove memmove
38
39/* Functions used by the included decompressor code below. */
40void *memmove(void *dest, const void *src, size_t n);
41
42/*
43 * This is set up by the setup-routine at boot-time
44 */
45struct boot_params *boot_params;
46
47memptr free_mem_ptr;
48memptr free_mem_end_ptr;
49
50static char *vidmem;
51static int vidport;
52static int lines, cols;
53
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
65
66#ifdef CONFIG_KERNEL_XZ
67#include "../../../../lib/decompress_unxz.c"
68#endif
69
70#ifdef CONFIG_KERNEL_LZO
71#include "../../../../lib/decompress_unlzo.c"
72#endif
73
74#ifdef CONFIG_KERNEL_LZ4
75#include "../../../../lib/decompress_unlz4.c"
76#endif
77/*
78 * NOTE: When adding a new decompressor, please update the analysis in
79 * ../header.S.
80 */
81
82static void scroll(void)
83{
84 int i;
85
86 memmove(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
87 for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
88 vidmem[i] = ' ';
89}
90
91#define XMTRDY 0x20
92
93#define TXR 0 /* Transmit register (WRITE) */
94#define LSR 5 /* Line Status */
95static 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
105void __putstr(const char *s)
106{
107 int x, y, pos;
108 char c;
109
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 }
118
119 if (boot_params->screen_info.orig_video_mode == 0 &&
120 lines == 0 && cols == 0)
121 return;
122
123 x = boot_params->screen_info.orig_x;
124 y = boot_params->screen_info.orig_y;
125
126 while ((c = *s++) != '\0') {
127 if (c == '\n') {
128 x = 0;
129 if (++y >= lines) {
130 scroll();
131 y--;
132 }
133 } else {
134 vidmem[(x + cols * y) * 2] = c;
135 if (++x >= cols) {
136 x = 0;
137 if (++y >= lines) {
138 scroll();
139 y--;
140 }
141 }
142 }
143 }
144
145 boot_params->screen_info.orig_x = x;
146 boot_params->screen_info.orig_y = y;
147
148 pos = (x + cols * y) * 2; /* Update cursor position */
149 outb(14, vidport);
150 outb(0xff & (pos >> 9), vidport+1);
151 outb(15, vidport);
152 outb(0xff & (pos >> 1), vidport+1);
153}
154
155void __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
172#if CONFIG_X86_NEED_RELOCS
173static void handle_relocations(void *output, unsigned long output_len,
174 unsigned long virt_addr)
175{
176 int *reloc;
177 unsigned long delta, map, ptr;
178 unsigned long min_addr = (unsigned long)output;
179 unsigned long max_addr = min_addr + (VO___bss_start - VO__text);
180
181 /*
182 * Calculate the delta between where vmlinux was linked to load
183 * and where it was actually loaded.
184 */
185 delta = min_addr - LOAD_PHYSICAL_ADDR;
186
187 /*
188 * The kernel contains a table of relocation addresses. Those
189 * addresses have the final load address of the kernel in virtual
190 * memory. We are currently working in the self map. So we need to
191 * create an adjustment for kernel memory addresses to the self map.
192 * This will involve subtracting out the base address of the kernel.
193 */
194 map = delta - __START_KERNEL_map;
195
196 /*
197 * 32-bit always performs relocations. 64-bit relocations are only
198 * needed if KASLR has chosen a different starting address offset
199 * from __START_KERNEL_map.
200 */
201 if (IS_ENABLED(CONFIG_X86_64))
202 delta = virt_addr - LOAD_PHYSICAL_ADDR;
203
204 if (!delta) {
205 debug_putstr("No relocation needed... ");
206 return;
207 }
208 debug_putstr("Performing relocations... ");
209
210 /*
211 * Process relocations: 32 bit relocations first then 64 bit after.
212 * Three sets of binary relocations are added to the end of the kernel
213 * before compression. Each relocation table entry is the kernel
214 * address of the location which needs to be updated stored as a
215 * 32-bit value which is sign extended to 64 bits.
216 *
217 * Format is:
218 *
219 * kernel bits...
220 * 0 - zero terminator for 64 bit relocations
221 * 64 bit relocation repeated
222 * 0 - zero terminator for inverse 32 bit relocations
223 * 32 bit inverse relocation repeated
224 * 0 - zero terminator for 32 bit relocations
225 * 32 bit relocation repeated
226 *
227 * So we work backwards from the end of the decompressed image.
228 */
229 for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
230 long extended = *reloc;
231 extended += map;
232
233 ptr = (unsigned long)extended;
234 if (ptr < min_addr || ptr > max_addr)
235 error("32-bit relocation outside of kernel!\n");
236
237 *(uint32_t *)ptr += delta;
238 }
239#ifdef CONFIG_X86_64
240 while (*--reloc) {
241 long extended = *reloc;
242 extended += map;
243
244 ptr = (unsigned long)extended;
245 if (ptr < min_addr || ptr > max_addr)
246 error("inverse 32-bit relocation outside of kernel!\n");
247
248 *(int32_t *)ptr -= delta;
249 }
250 for (reloc--; *reloc; reloc--) {
251 long extended = *reloc;
252 extended += map;
253
254 ptr = (unsigned long)extended;
255 if (ptr < min_addr || ptr > max_addr)
256 error("64-bit relocation outside of kernel!\n");
257
258 *(uint64_t *)ptr += delta;
259 }
260#endif
261}
262#else
263static inline void handle_relocations(void *output, unsigned long output_len,
264 unsigned long virt_addr)
265{ }
266#endif
267
268static void parse_elf(void *output)
269{
270#ifdef CONFIG_X86_64
271 Elf64_Ehdr ehdr;
272 Elf64_Phdr *phdrs, *phdr;
273#else
274 Elf32_Ehdr ehdr;
275 Elf32_Phdr *phdrs, *phdr;
276#endif
277 void *dest;
278 int i;
279
280 memcpy(&ehdr, output, sizeof(ehdr));
281 if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
282 ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
283 ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
284 ehdr.e_ident[EI_MAG3] != ELFMAG3) {
285 error("Kernel is not a valid ELF file");
286 return;
287 }
288
289 debug_putstr("Parsing ELF... ");
290
291 phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
292 if (!phdrs)
293 error("Failed to allocate space for phdrs");
294
295 memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);
296
297 for (i = 0; i < ehdr.e_phnum; i++) {
298 phdr = &phdrs[i];
299
300 switch (phdr->p_type) {
301 case PT_LOAD:
302#ifdef CONFIG_RELOCATABLE
303 dest = output;
304 dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
305#else
306 dest = (void *)(phdr->p_paddr);
307#endif
308 memmove(dest, output + phdr->p_offset, phdr->p_filesz);
309 break;
310 default: /* Ignore other PT_* */ break;
311 }
312 }
313
314 free(phdrs);
315}
316
317/*
318 * The compressed kernel image (ZO), has been moved so that its position
319 * is against the end of the buffer used to hold the uncompressed kernel
320 * image (VO) and the execution environment (.bss, .brk), which makes sure
321 * there is room to do the in-place decompression. (See header.S for the
322 * calculations.)
323 *
324 * |-----compressed kernel image------|
325 * V V
326 * 0 extract_offset +INIT_SIZE
327 * |-----------|---------------|-------------------------|--------|
328 * | | | |
329 * VO__text startup_32 of ZO VO__end ZO__end
330 * ^ ^
331 * |-------uncompressed kernel image---------|
332 *
333 */
334asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
335 unsigned char *input_data,
336 unsigned long input_len,
337 unsigned char *output,
338 unsigned long output_len)
339{
340 const unsigned long kernel_total_size = VO__end - VO__text;
341 unsigned long virt_addr = (unsigned long)output;
342
343 /* Retain x86 boot parameters pointer passed from startup_32/64. */
344 boot_params = rmode;
345
346 /* Clear flags intended for solely in-kernel use. */
347 boot_params->hdr.loadflags &= ~KASLR_FLAG;
348
349 sanitize_boot_params(boot_params);
350
351 if (boot_params->screen_info.orig_video_mode == 7) {
352 vidmem = (char *) 0xb0000;
353 vidport = 0x3b4;
354 } else {
355 vidmem = (char *) 0xb8000;
356 vidport = 0x3d4;
357 }
358
359 lines = boot_params->screen_info.orig_video_lines;
360 cols = boot_params->screen_info.orig_video_cols;
361
362 console_init();
363 debug_putstr("early console in extract_kernel\n");
364
365 free_mem_ptr = heap; /* Heap */
366 free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
367
368 /* Report initial kernel position details. */
369 debug_putaddr(input_data);
370 debug_putaddr(input_len);
371 debug_putaddr(output);
372 debug_putaddr(output_len);
373 debug_putaddr(kernel_total_size);
374
375 /*
376 * The memory hole needed for the kernel is the larger of either
377 * the entire decompressed kernel plus relocation table, or the
378 * entire decompressed kernel plus .bss and .brk sections.
379 */
380 choose_random_location((unsigned long)input_data, input_len,
381 (unsigned long *)&output,
382 max(output_len, kernel_total_size),
383 &virt_addr);
384
385 /* Validate memory location choices. */
386 if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
387 error("Destination physical address inappropriately aligned");
388 if (virt_addr & (MIN_KERNEL_ALIGN - 1))
389 error("Destination virtual address inappropriately aligned");
390#ifdef CONFIG_X86_64
391 if (heap > 0x3fffffffffffUL)
392 error("Destination address too large");
393#else
394 if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
395 error("Destination address too large");
396#endif
397#ifndef CONFIG_RELOCATABLE
398 if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
399 error("Destination address does not match LOAD_PHYSICAL_ADDR");
400 if ((unsigned long)output != virt_addr)
401 error("Destination virtual address changed when not relocatable");
402#endif
403
404 debug_putstr("\nDecompressing Linux... ");
405 __decompress(input_data, input_len, NULL, NULL, output, output_len,
406 NULL, error);
407 parse_elf(output);
408 handle_relocations(output, output_len, virt_addr);
409 debug_putstr("done.\nBooting the kernel.\n");
410 return output;
411}