1 /*
2 * Definitions and wrapper functions for kernel decompressor
3 *
4 * (C) 2017 Helge Deller <deller@gmx.de>
5 */
6
7 #include <linux/uaccess.h>
8 #include <linux/elf.h>
9 #include <asm/unaligned.h>
10 #include <asm/page.h>
11 #include "sizes.h"
12
13 /*
14 * gzip declarations
15 */
16 #define STATIC static
17
18 #undef memmove
19 #define memmove memmove
20 #define memzero(s, n) memset((s), 0, (n))
21
22 #define malloc malloc_gzip
23 #define free free_gzip
24
25 /* Symbols defined by linker scripts */
26 extern char input_data[];
27 extern int input_len;
28 /* output_len is inserted by the linker possibly at an unaligned address */
29 extern char output_len;
30 extern char _text, _end;
31 extern char _bss, _ebss;
32 extern char _startcode_end;
33 extern void startup_continue(void *entry, unsigned long cmdline,
34 unsigned long rd_start, unsigned long rd_end) __noreturn;
35
36 void error(char *m) __noreturn;
37
38 static unsigned long free_mem_ptr;
39 static unsigned long free_mem_end_ptr;
40
41 #ifdef CONFIG_KERNEL_GZIP
42 #include "../../../../lib/decompress_inflate.c"
43 #endif
44
45 #ifdef CONFIG_KERNEL_BZIP2
46 #include "../../../../lib/decompress_bunzip2.c"
47 #endif
48
49 #ifdef CONFIG_KERNEL_LZ4
50 #include "../../../../lib/decompress_unlz4.c"
51 #endif
52
53 #ifdef CONFIG_KERNEL_LZMA
54 #include "../../../../lib/decompress_unlzma.c"
55 #endif
56
57 #ifdef CONFIG_KERNEL_LZO
58 #include "../../../../lib/decompress_unlzo.c"
59 #endif
60
61 #ifdef CONFIG_KERNEL_XZ
62 #include "../../../../lib/decompress_unxz.c"
63 #endif
64
memmove(void * dest,const void * src,size_t n)65 void *memmove(void *dest, const void *src, size_t n)
66 {
67 const char *s = src;
68 char *d = dest;
69
70 if (d <= s) {
71 while (n--)
72 *d++ = *s++;
73 } else {
74 d += n;
75 s += n;
76 while (n--)
77 *--d = *--s;
78 }
79 return dest;
80 }
81
memset(void * s,int c,size_t count)82 void *memset(void *s, int c, size_t count)
83 {
84 char *xs = (char *)s;
85
86 while (count--)
87 *xs++ = c;
88 return s;
89 }
90
memcpy(void * d,const void * s,size_t len)91 void *memcpy(void *d, const void *s, size_t len)
92 {
93 char *dest = (char *)d;
94 const char *source = (const char *)s;
95
96 while (len--)
97 *dest++ = *source++;
98 return d;
99 }
100
strlen(const char * s)101 size_t strlen(const char *s)
102 {
103 const char *sc;
104
105 for (sc = s; *sc != '\0'; ++sc)
106 ;
107 return sc - s;
108 }
109
strchr(const char * s,int c)110 char *strchr(const char *s, int c)
111 {
112 while (*s) {
113 if (*s == (char)c)
114 return (char *)s;
115 ++s;
116 }
117 return NULL;
118 }
119
puts(const char * s)120 static int puts(const char *s)
121 {
122 const char *nuline = s;
123
124 while ((nuline = strchr(s, '\n')) != NULL) {
125 if (nuline != s)
126 pdc_iodc_print(s, nuline - s);
127 pdc_iodc_print("\r\n", 2);
128 s = nuline + 1;
129 }
130 if (*s != '\0')
131 pdc_iodc_print(s, strlen(s));
132
133 return 0;
134 }
135
putchar(int c)136 static int putchar(int c)
137 {
138 char buf[2];
139
140 buf[0] = c;
141 buf[1] = '\0';
142 puts(buf);
143 return c;
144 }
145
error(char * x)146 void __noreturn error(char *x)
147 {
148 if (x) puts(x);
149 puts("\n -- System halted\n");
150 while (1) /* wait forever */
151 ;
152 }
153
print_num(unsigned long num,int base)154 static int print_num(unsigned long num, int base)
155 {
156 const char hex[] = "0123456789abcdef";
157 char str[40];
158 int i = sizeof(str)-1;
159
160 str[i--] = '\0';
161 do {
162 str[i--] = hex[num % base];
163 num = num / base;
164 } while (num);
165
166 if (base == 16) {
167 str[i--] = 'x';
168 str[i] = '0';
169 } else i++;
170 puts(&str[i]);
171
172 return 0;
173 }
174
printf(const char * fmt,...)175 static int printf(const char *fmt, ...)
176 {
177 va_list args;
178 int i = 0;
179
180 va_start(args, fmt);
181
182 while (fmt[i]) {
183 if (fmt[i] != '%') {
184 put:
185 putchar(fmt[i++]);
186 continue;
187 }
188
189 if (fmt[++i] == '%')
190 goto put;
191 print_num(va_arg(args, unsigned long),
192 fmt[i] == 'x' ? 16:10);
193 ++i;
194 }
195
196 va_end(args);
197 return 0;
198 }
199
200 /* helper functions for libgcc */
abort(void)201 void abort(void)
202 {
203 error("aborted.");
204 }
205
206 #undef malloc
malloc(size_t size)207 static void *malloc(size_t size)
208 {
209 return malloc_gzip(size);
210 }
211
212 #undef free
free(void * ptr)213 static void free(void *ptr)
214 {
215 return free_gzip(ptr);
216 }
217
218
flush_data_cache(char * start,unsigned long length)219 static void flush_data_cache(char *start, unsigned long length)
220 {
221 char *end = start + length;
222
223 do {
224 asm volatile("fdc 0(%0)" : : "r" (start));
225 asm volatile("fic 0(%%sr0,%0)" : : "r" (start));
226 start += 16;
227 } while (start < end);
228 asm volatile("fdc 0(%0)" : : "r" (end));
229
230 asm ("sync");
231 }
232
parse_elf(void * output)233 static void parse_elf(void *output)
234 {
235 #ifdef CONFIG_64BIT
236 Elf64_Ehdr ehdr;
237 Elf64_Phdr *phdrs, *phdr;
238 #else
239 Elf32_Ehdr ehdr;
240 Elf32_Phdr *phdrs, *phdr;
241 #endif
242 void *dest;
243 int i;
244
245 memcpy(&ehdr, output, sizeof(ehdr));
246 if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
247 ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
248 ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
249 ehdr.e_ident[EI_MAG3] != ELFMAG3) {
250 error("Kernel is not a valid ELF file");
251 return;
252 }
253
254 #ifdef DEBUG
255 printf("Parsing ELF... ");
256 #endif
257
258 phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
259 if (!phdrs)
260 error("Failed to allocate space for phdrs");
261
262 memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);
263
264 for (i = 0; i < ehdr.e_phnum; i++) {
265 phdr = &phdrs[i];
266
267 switch (phdr->p_type) {
268 case PT_LOAD:
269 dest = (void *)((unsigned long) phdr->p_paddr &
270 (__PAGE_OFFSET_DEFAULT-1));
271 memmove(dest, output + phdr->p_offset, phdr->p_filesz);
272 break;
273 default:
274 break;
275 }
276 }
277
278 free(phdrs);
279 }
280
decompress_kernel(unsigned int started_wide,unsigned int command_line,const unsigned int rd_start,const unsigned int rd_end)281 asmlinkage unsigned long __visible decompress_kernel(unsigned int started_wide,
282 unsigned int command_line,
283 const unsigned int rd_start,
284 const unsigned int rd_end)
285 {
286 char *output;
287 unsigned long vmlinux_addr, vmlinux_len;
288 unsigned long kernel_addr, kernel_len;
289
290 #ifdef CONFIG_64BIT
291 parisc_narrow_firmware = 0;
292 #endif
293
294 set_firmware_width_unlocked();
295
296 putchar('D'); /* if you get this D and no more, string storage */
297 /* in $GLOBAL$ is wrong or %dp is wrong */
298 puts("ecompressing Linux... ");
299
300 /* where the final bits are stored */
301 kernel_addr = KERNEL_BINARY_TEXT_START;
302 kernel_len = __pa(SZ_end) - __pa(SZparisc_kernel_start);
303 if ((unsigned long) &_startcode_end > kernel_addr)
304 error("Bootcode overlaps kernel code");
305
306 /*
307 * Calculate addr to where the vmlinux ELF file shall be decompressed.
308 * Assembly code in head.S positioned the stack directly behind bss, so
309 * leave 2 MB for the stack.
310 */
311 vmlinux_addr = (unsigned long) &_ebss + 2*1024*1024;
312 vmlinux_len = get_unaligned_le32(&output_len);
313 output = (char *) vmlinux_addr;
314
315 /*
316 * Initialize free_mem_ptr and free_mem_end_ptr.
317 */
318 free_mem_ptr = vmlinux_addr + vmlinux_len;
319
320 /* Limit memory for bootoader to 1GB */
321 #define ARTIFICIAL_LIMIT (1*1024*1024*1024)
322 free_mem_end_ptr = PAGE0->imm_max_mem;
323 if (free_mem_end_ptr > ARTIFICIAL_LIMIT)
324 free_mem_end_ptr = ARTIFICIAL_LIMIT;
325
326 #ifdef CONFIG_BLK_DEV_INITRD
327 /* if we have ramdisk this is at end of memory */
328 if (rd_start && rd_start < free_mem_end_ptr)
329 free_mem_end_ptr = rd_start;
330 #endif
331
332 if (free_mem_ptr >= free_mem_end_ptr) {
333 int free_ram;
334 free_ram = (free_mem_ptr >> 20) + 1;
335 if (free_ram < 32)
336 free_ram = 32;
337 printf("\nKernel requires at least %d MB RAM.\n",
338 free_ram);
339 error(NULL);
340 }
341
342 #ifdef DEBUG
343 printf("\n");
344 printf("startcode_end = %x\n", &_startcode_end);
345 printf("commandline = %x\n", command_line);
346 printf("rd_start = %x\n", rd_start);
347 printf("rd_end = %x\n", rd_end);
348
349 printf("free_ptr = %x\n", free_mem_ptr);
350 printf("free_ptr_end = %x\n", free_mem_end_ptr);
351
352 printf("input_data = %x\n", input_data);
353 printf("input_len = %x\n", input_len);
354 printf("output = %x\n", output);
355 printf("output_len = %x\n", vmlinux_len);
356 printf("kernel_addr = %x\n", kernel_addr);
357 printf("kernel_len = %x\n", kernel_len);
358 #endif
359
360 __decompress(input_data, input_len, NULL, NULL,
361 output, 0, NULL, error);
362 parse_elf(output);
363
364 output = (char *) kernel_addr;
365 flush_data_cache(output, kernel_len);
366
367 printf("done.\nBooting the kernel.\n");
368
369 return (unsigned long) output;
370 }
371
