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12#include "misc.h"
13#include "../string.h"
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99#define STATIC static
100
101#undef memcpy
102
103
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105
106
107
108#undef memset
109#define memzero(s, n) memset((s), 0, (n))
110
111
112static void error(char *m);
113
114
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116
117struct boot_params *real_mode;
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
162#define LSR 5
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;
217 outb(14, vidport);
218 outb(0xff & (pos >> 9), vidport+1);
219 outb(15, vidport);
220 outb(0xff & (pos >> 1), vidport+1);
221}
222
223void __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
240static void error(char *x)
241{
242 error_putstr("\n\n");
243 error_putstr(x);
244 error_putstr("\n\n -- System halted");
245
246 while (1)
247 asm("hlt");
248}
249
250#if CONFIG_X86_NEED_RELOCS
251static 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
260
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
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275
276 map = delta - __START_KERNEL_map;
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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
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 }
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
331static inline void handle_relocations(void *output, unsigned long output_len)
332{ }
333#endif
334
335static 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));
348 if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
349 ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
350 ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
351 ehdr.e_ident[EI_MAG3] != ELFMAG3) {
352 error("Kernel is not a valid ELF file");
353 return;
354 }
355
356 debug_putstr("Parsing ELF... ");
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
364 for (i = 0; i < ehdr.e_phnum; i++) {
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
373 dest = (void *)(phdr->p_paddr);
374#endif
375 memcpy(dest,
376 output + phdr->p_offset,
377 phdr->p_filesz);
378 break;
379 default: break;
380 }
381 }
382
383 free(phdrs);
384}
385
386asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap,
387 unsigned char *input_data,
388 unsigned long input_len,
389 unsigned char *output,
390 unsigned long output_len,
391 unsigned long run_size)
392{
393 unsigned char *output_orig = output;
394
395 real_mode = rmode;
396
397
398 real_mode->hdr.loadflags &= ~KASLR_FLAG;
399
400 sanitize_boot_params(real_mode);
401
402 if (real_mode->screen_info.orig_video_mode == 7) {
403 vidmem = (char *) 0xb0000;
404 vidport = 0x3b4;
405 } else {
406 vidmem = (char *) 0xb8000;
407 vidport = 0x3d4;
408 }
409
410 lines = real_mode->screen_info.orig_video_lines;
411 cols = real_mode->screen_info.orig_video_cols;
412
413 console_init();
414 debug_putstr("early console in decompress_kernel\n");
415
416 free_mem_ptr = heap;
417 free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
418
419
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
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431 output = choose_kernel_location(real_mode, input_data, input_len, output,
432 output_len > run_size ? output_len
433 : run_size);
434
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436 if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
437 error("Destination address inappropriately aligned");
438#ifdef CONFIG_X86_64
439 if (heap > 0x3fffffffffffUL)
440 error("Destination address too large");
441#else
442 if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
443 error("Destination address too large");
444#endif
445#ifndef CONFIG_RELOCATABLE
446 if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
447 error("Wrong destination address");
448#endif
449
450 debug_putstr("\nDecompressing Linux... ");
451 __decompress(input_data, input_len, NULL, NULL, output, output_len,
452 NULL, error);
453 parse_elf(output);
454
455
456
457
458 if (!IS_ENABLED(CONFIG_X86_64) || output != output_orig)
459 handle_relocations(output, output_len);
460 debug_putstr("done.\nBooting the kernel.\n");
461 return output;
462}
463