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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * misc.c
4 *
5 * This is a collection of several routines used to extract the kernel
6 * which includes KASLR relocation, decompression, ELF parsing, and
7 * relocation processing. Additionally included are the screen and serial
8 * output functions and related debugging support functions.
9 *
10 * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
11 * puts by Nick Holloway 1993, better puts by Martin Mares 1995
12 * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
13 */
14
15#include "misc.h"
16#include "error.h"
17#include "pgtable.h"
18#include "../string.h"
19#include "../voffset.h"
20#include <asm/bootparam_utils.h>
21
22/*
23 * WARNING!!
24 * This code is compiled with -fPIC and it is relocated dynamically at
25 * run time, but no relocation processing is performed. This means that
26 * it is not safe to place pointers in static structures.
27 */
28
29/* Macros used by the included decompressor code below. */
30#define STATIC static
31
32/*
33 * Use normal definitions of mem*() from string.c. There are already
34 * included header files which expect a definition of memset() and by
35 * the time we define memset macro, it is too late.
36 */
37#undef memcpy
38#undef memset
39#define memzero(s, n) memset((s), 0, (n))
40#define memmove memmove
41
42/* Functions used by the included decompressor code below. */
43void *memmove(void *dest, const void *src, size_t n);
44
45/*
46 * This is set up by the setup-routine at boot-time
47 */
48struct boot_params *boot_params;
49
50memptr free_mem_ptr;
51memptr free_mem_end_ptr;
52
53static char *vidmem;
54static int vidport;
55static int lines, cols;
56
57#ifdef CONFIG_KERNEL_GZIP
58#include "../../../../lib/decompress_inflate.c"
59#endif
60
61#ifdef CONFIG_KERNEL_BZIP2
62#include "../../../../lib/decompress_bunzip2.c"
63#endif
64
65#ifdef CONFIG_KERNEL_LZMA
66#include "../../../../lib/decompress_unlzma.c"
67#endif
68
69#ifdef CONFIG_KERNEL_XZ
70#include "../../../../lib/decompress_unxz.c"
71#endif
72
73#ifdef CONFIG_KERNEL_LZO
74#include "../../../../lib/decompress_unlzo.c"
75#endif
76
77#ifdef CONFIG_KERNEL_LZ4
78#include "../../../../lib/decompress_unlz4.c"
79#endif
80/*
81 * NOTE: When adding a new decompressor, please update the analysis in
82 * ../header.S.
83 */
84
85static void scroll(void)
86{
87 int i;
88
89 memmove(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
90 for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
91 vidmem[i] = ' ';
92}
93
94#define XMTRDY 0x20
95
96#define TXR 0 /* Transmit register (WRITE) */
97#define LSR 5 /* Line Status */
98static void serial_putchar(int ch)
99{
100 unsigned timeout = 0xffff;
101
102 while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
103 cpu_relax();
104
105 outb(ch, early_serial_base + TXR);
106}
107
108void __putstr(const char *s)
109{
110 int x, y, pos;
111 char c;
112
113 if (early_serial_base) {
114 const char *str = s;
115 while (*str) {
116 if (*str == '\n')
117 serial_putchar('\r');
118 serial_putchar(*str++);
119 }
120 }
121
122 if (lines == 0 || cols == 0)
123 return;
124
125 x = boot_params->screen_info.orig_x;
126 y = boot_params->screen_info.orig_y;
127
128 while ((c = *s++) != '\0') {
129 if (c == '\n') {
130 x = 0;
131 if (++y >= lines) {
132 scroll();
133 y--;
134 }
135 } else {
136 vidmem[(x + cols * y) * 2] = c;
137 if (++x >= cols) {
138 x = 0;
139 if (++y >= lines) {
140 scroll();
141 y--;
142 }
143 }
144 }
145 }
146
147 boot_params->screen_info.orig_x = x;
148 boot_params->screen_info.orig_y = y;
149
150 pos = (x + cols * y) * 2; /* Update cursor position */
151 outb(14, vidport);
152 outb(0xff & (pos >> 9), vidport+1);
153 outb(15, vidport);
154 outb(0xff & (pos >> 1), vidport+1);
155}
156
157void __puthex(unsigned long value)
158{
159 char alpha[2] = "0";
160 int bits;
161
162 for (bits = sizeof(value) * 8 - 4; bits >= 0; bits -= 4) {
163 unsigned long digit = (value >> bits) & 0xf;
164
165 if (digit < 0xA)
166 alpha[0] = '0' + digit;
167 else
168 alpha[0] = 'a' + (digit - 0xA);
169
170 __putstr(alpha);
171 }
172}
173
174#if CONFIG_X86_NEED_RELOCS
175static void handle_relocations(void *output, unsigned long output_len,
176 unsigned long virt_addr)
177{
178 int *reloc;
179 unsigned long delta, map, ptr;
180 unsigned long min_addr = (unsigned long)output;
181 unsigned long max_addr = min_addr + (VO___bss_start - VO__text);
182
183 /*
184 * Calculate the delta between where vmlinux was linked to load
185 * and where it was actually loaded.
186 */
187 delta = min_addr - LOAD_PHYSICAL_ADDR;
188
189 /*
190 * The kernel contains a table of relocation addresses. Those
191 * addresses have the final load address of the kernel in virtual
192 * memory. We are currently working in the self map. So we need to
193 * create an adjustment for kernel memory addresses to the self map.
194 * This will involve subtracting out the base address of the kernel.
195 */
196 map = delta - __START_KERNEL_map;
197
198 /*
199 * 32-bit always performs relocations. 64-bit relocations are only
200 * needed if KASLR has chosen a different starting address offset
201 * from __START_KERNEL_map.
202 */
203 if (IS_ENABLED(CONFIG_X86_64))
204 delta = virt_addr - LOAD_PHYSICAL_ADDR;
205
206 if (!delta) {
207 debug_putstr("No relocation needed... ");
208 return;
209 }
210 debug_putstr("Performing relocations... ");
211
212 /*
213 * Process relocations: 32 bit relocations first then 64 bit after.
214 * Three sets of binary relocations are added to the end of the kernel
215 * before compression. Each relocation table entry is the kernel
216 * address of the location which needs to be updated stored as a
217 * 32-bit value which is sign extended to 64 bits.
218 *
219 * Format is:
220 *
221 * kernel bits...
222 * 0 - zero terminator for 64 bit relocations
223 * 64 bit relocation repeated
224 * 0 - zero terminator for inverse 32 bit relocations
225 * 32 bit inverse relocation repeated
226 * 0 - zero terminator for 32 bit relocations
227 * 32 bit relocation repeated
228 *
229 * So we work backwards from the end of the decompressed image.
230 */
231 for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
232 long extended = *reloc;
233 extended += map;
234
235 ptr = (unsigned long)extended;
236 if (ptr < min_addr || ptr > max_addr)
237 error("32-bit relocation outside of kernel!\n");
238
239 *(uint32_t *)ptr += delta;
240 }
241#ifdef CONFIG_X86_64
242 while (*--reloc) {
243 long extended = *reloc;
244 extended += map;
245
246 ptr = (unsigned long)extended;
247 if (ptr < min_addr || ptr > max_addr)
248 error("inverse 32-bit relocation outside of kernel!\n");
249
250 *(int32_t *)ptr -= delta;
251 }
252 for (reloc--; *reloc; reloc--) {
253 long extended = *reloc;
254 extended += map;
255
256 ptr = (unsigned long)extended;
257 if (ptr < min_addr || ptr > max_addr)
258 error("64-bit relocation outside of kernel!\n");
259
260 *(uint64_t *)ptr += delta;
261 }
262#endif
263}
264#else
265static inline void handle_relocations(void *output, unsigned long output_len,
266 unsigned long virt_addr)
267{ }
268#endif
269
270static void parse_elf(void *output)
271{
272#ifdef CONFIG_X86_64
273 Elf64_Ehdr ehdr;
274 Elf64_Phdr *phdrs, *phdr;
275#else
276 Elf32_Ehdr ehdr;
277 Elf32_Phdr *phdrs, *phdr;
278#endif
279 void *dest;
280 int i;
281
282 memcpy(&ehdr, output, sizeof(ehdr));
283 if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
284 ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
285 ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
286 ehdr.e_ident[EI_MAG3] != ELFMAG3) {
287 error("Kernel is not a valid ELF file");
288 return;
289 }
290
291 debug_putstr("Parsing ELF... ");
292
293 phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
294 if (!phdrs)
295 error("Failed to allocate space for phdrs");
296
297 memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);
298
299 for (i = 0; i < ehdr.e_phnum; i++) {
300 phdr = &phdrs[i];
301
302 switch (phdr->p_type) {
303 case PT_LOAD:
304#ifdef CONFIG_X86_64
305 if ((phdr->p_align % 0x200000) != 0)
306 error("Alignment of LOAD segment isn't multiple of 2MB");
307#endif
308#ifdef CONFIG_RELOCATABLE
309 dest = output;
310 dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
311#else
312 dest = (void *)(phdr->p_paddr);
313#endif
314 memmove(dest, output + phdr->p_offset, phdr->p_filesz);
315 break;
316 default: /* Ignore other PT_* */ break;
317 }
318 }
319
320 free(phdrs);
321}
322
323/*
324 * The compressed kernel image (ZO), has been moved so that its position
325 * is against the end of the buffer used to hold the uncompressed kernel
326 * image (VO) and the execution environment (.bss, .brk), which makes sure
327 * there is room to do the in-place decompression. (See header.S for the
328 * calculations.)
329 *
330 * |-----compressed kernel image------|
331 * V V
332 * 0 extract_offset +INIT_SIZE
333 * |-----------|---------------|-------------------------|--------|
334 * | | | |
335 * VO__text startup_32 of ZO VO__end ZO__end
336 * ^ ^
337 * |-------uncompressed kernel image---------|
338 *
339 */
340asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
341 unsigned char *input_data,
342 unsigned long input_len,
343 unsigned char *output,
344 unsigned long output_len)
345{
346 const unsigned long kernel_total_size = VO__end - VO__text;
347 unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
348 unsigned long needed_size;
349
350 /* Retain x86 boot parameters pointer passed from startup_32/64. */
351 boot_params = rmode;
352
353 /* Clear flags intended for solely in-kernel use. */
354 boot_params->hdr.loadflags &= ~KASLR_FLAG;
355
356 sanitize_boot_params(boot_params);
357
358 if (boot_params->screen_info.orig_video_mode == 7) {
359 vidmem = (char *) 0xb0000;
360 vidport = 0x3b4;
361 } else {
362 vidmem = (char *) 0xb8000;
363 vidport = 0x3d4;
364 }
365
366 lines = boot_params->screen_info.orig_video_lines;
367 cols = boot_params->screen_info.orig_video_cols;
368
369 console_init();
370
371 /*
372 * Save RSDP address for later use. Have this after console_init()
373 * so that early debugging output from the RSDP parsing code can be
374 * collected.
375 */
376 boot_params->acpi_rsdp_addr = get_rsdp_addr();
377
378 debug_putstr("early console in extract_kernel\n");
379
380 free_mem_ptr = heap; /* Heap */
381 free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
382
383 /*
384 * The memory hole needed for the kernel is the larger of either
385 * the entire decompressed kernel plus relocation table, or the
386 * entire decompressed kernel plus .bss and .brk sections.
387 *
388 * On X86_64, the memory is mapped with PMD pages. Round the
389 * size up so that the full extent of PMD pages mapped is
390 * included in the check against the valid memory table
391 * entries. This ensures the full mapped area is usable RAM
392 * and doesn't include any reserved areas.
393 */
394 needed_size = max(output_len, kernel_total_size);
395#ifdef CONFIG_X86_64
396 needed_size = ALIGN(needed_size, MIN_KERNEL_ALIGN);
397#endif
398
399 /* Report initial kernel position details. */
400 debug_putaddr(input_data);
401 debug_putaddr(input_len);
402 debug_putaddr(output);
403 debug_putaddr(output_len);
404 debug_putaddr(kernel_total_size);
405 debug_putaddr(needed_size);
406
407#ifdef CONFIG_X86_64
408 /* Report address of 32-bit trampoline */
409 debug_putaddr(trampoline_32bit);
410#endif
411
412 choose_random_location((unsigned long)input_data, input_len,
413 (unsigned long *)&output,
414 needed_size,
415 &virt_addr);
416
417 /* Validate memory location choices. */
418 if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
419 error("Destination physical address inappropriately aligned");
420 if (virt_addr & (MIN_KERNEL_ALIGN - 1))
421 error("Destination virtual address inappropriately aligned");
422#ifdef CONFIG_X86_64
423 if (heap > 0x3fffffffffffUL)
424 error("Destination address too large");
425 if (virt_addr + max(output_len, kernel_total_size) > KERNEL_IMAGE_SIZE)
426 error("Destination virtual address is beyond the kernel mapping area");
427#else
428 if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
429 error("Destination address too large");
430#endif
431#ifndef CONFIG_RELOCATABLE
432 if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
433 error("Destination address does not match LOAD_PHYSICAL_ADDR");
434 if (virt_addr != LOAD_PHYSICAL_ADDR)
435 error("Destination virtual address changed when not relocatable");
436#endif
437
438 debug_putstr("\nDecompressing Linux... ");
439 __decompress(input_data, input_len, NULL, NULL, output, output_len,
440 NULL, error);
441 parse_elf(output);
442 handle_relocations(output, output_len, virt_addr);
443 debug_putstr("done.\nBooting the kernel.\n");
444 return output;
445}
446
447void fortify_panic(const char *name)
448{
449 error("detected buffer overflow");
450}
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}