4 * This is a collection of several routines from gzip-1.0.3
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
13 * we have to be careful, because no indirections are allowed here, and
14 * paravirt_ops is a kind of one. As it will only run in baremetal anyway,
15 * we just keep it from happening
17 #undef CONFIG_PARAVIRT
19 #define _ASM_X86_DESC_H 1
23 #define _LINUX_STRING_H_ 1
24 #define __LINUX_BITMAP_H 1
27 #include <linux/linkage.h>
28 #include <linux/screen_info.h>
29 #include <linux/elf.h>
33 #include <asm/bootparam.h>
36 * This code is compiled with -fPIC and it is relocated dynamically
37 * at run time, but no relocation processing is performed.
38 * This means that it is not safe to place pointers in static structures.
42 * Getting to provable safe in place decompression is hard.
43 * Worst case behaviours need to be analyzed.
44 * Background information:
53 * compressed data blocks[N]
56 * resulting in 18 bytes of non compressed data overhead.
58 * Files divided into blocks
59 * 1 bit (last block flag)
62 * 1 block occurs every 32K -1 bytes or when there 50% compression
63 * has been achieved. The smallest block type encoding is always used.
66 * 32 bits length in bytes.
73 * dynamic tree encoding.
77 * The buffer for decompression in place is the length of the
78 * uncompressed data, plus a small amount extra to keep the algorithm safe.
79 * The compressed data is placed at the end of the buffer. The output
80 * pointer is placed at the start of the buffer and the input pointer
81 * is placed where the compressed data starts. Problems will occur
82 * when the output pointer overruns the input pointer.
84 * The output pointer can only overrun the input pointer if the input
85 * pointer is moving faster than the output pointer. A condition only
86 * triggered by data whose compressed form is larger than the uncompressed
89 * The worst case at the block level is a growth of the compressed data
90 * of 5 bytes per 32767 bytes.
92 * The worst case internal to a compressed block is very hard to figure.
93 * The worst case can at least be boundined by having one bit that represents
94 * 32764 bytes and then all of the rest of the bytes representing the very
97 * All of which is enough to compute an amount of extra data that is required
98 * to be safe. To avoid problems at the block level allocating 5 extra bytes
99 * per 32767 bytes of data is sufficient. To avoind problems internal to a
100 * block adding an extra 32767 bytes (the worst case uncompressed block size)
101 * is sufficient, to ensure that in the worst case the decompressed data for
102 * block will stop the byte before the compressed data for a block begins.
103 * To avoid problems with the compressed data's meta information an extra 18
104 * bytes are needed. Leading to the formula:
106 * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
108 * Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
109 * Adding 32768 instead of 32767 just makes for round numbers.
110 * Adding the decompressor_size is necessary as it musht live after all
111 * of the data as well. Last I measured the decompressor is about 14K.
112 * 10K of actual data and 4K of bss.
119 #define STATIC static
123 #define memzero(s, n) memset((s), 0, (n))
126 static void error(char *m);
129 * This is set up by the setup-routine at boot-time
131 static struct boot_params *real_mode; /* Pointer to real-mode data */
134 static void *memset(void *s, int c, unsigned n);
135 void *memcpy(void *dest, const void *src, unsigned n);
137 static void __putstr(int, const char *);
138 #define putstr(__x) __putstr(0, __x)
143 #define memptr unsigned
146 static memptr free_mem_ptr;
147 static memptr free_mem_end_ptr;
151 static int lines, cols;
153 #ifdef CONFIG_KERNEL_GZIP
154 #include "../../../../lib/decompress_inflate.c"
157 #ifdef CONFIG_KERNEL_BZIP2
158 #include "../../../../lib/decompress_bunzip2.c"
161 #ifdef CONFIG_KERNEL_LZMA
162 #include "../../../../lib/decompress_unlzma.c"
165 #ifdef CONFIG_KERNEL_LZO
166 #include "../../../../lib/decompress_unlzo.c"
169 static void scroll(void)
173 memcpy(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
174 for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
178 static void __putstr(int error, const char *s)
183 #ifndef CONFIG_X86_VERBOSE_BOOTUP
189 if (real_mode->screen_info.orig_video_mode == 0 &&
190 lines == 0 && cols == 0)
194 x = real_mode->screen_info.orig_x;
195 y = real_mode->screen_info.orig_y;
197 while ((c = *s++) != '\0') {
205 vidmem[(x + cols * y) * 2] = c;
216 real_mode->screen_info.orig_x = x;
217 real_mode->screen_info.orig_y = y;
219 pos = (x + cols * y) * 2; /* Update cursor position */
221 outb(0xff & (pos >> 9), vidport+1);
223 outb(0xff & (pos >> 1), vidport+1);
226 static void *memset(void *s, int c, unsigned n)
231 for (i = 0; i < n; i++)
236 void *memcpy(void *dest, const void *src, unsigned n)
242 for (i = 0; i < n; i++)
248 static void error(char *x)
252 __putstr(1, "\n\n -- System halted");
258 static void parse_elf(void *output)
262 Elf64_Phdr *phdrs, *phdr;
265 Elf32_Phdr *phdrs, *phdr;
270 memcpy(&ehdr, output, sizeof(ehdr));
271 if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
272 ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
273 ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
274 ehdr.e_ident[EI_MAG3] != ELFMAG3) {
275 error("Kernel is not a valid ELF file");
280 putstr("Parsing ELF... ");
282 phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
284 error("Failed to allocate space for phdrs");
286 memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);
288 for (i = 0; i < ehdr.e_phnum; i++) {
291 switch (phdr->p_type) {
293 #ifdef CONFIG_RELOCATABLE
295 dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
297 dest = (void *)(phdr->p_paddr);
300 output + phdr->p_offset,
303 default: /* Ignore other PT_* */ break;
308 asmlinkage void decompress_kernel(void *rmode, memptr heap,
309 unsigned char *input_data,
310 unsigned long input_len,
311 unsigned char *output)
315 if (real_mode->hdr.loadflags & QUIET_FLAG)
318 if (real_mode->screen_info.orig_video_mode == 7) {
319 vidmem = (char *) 0xb0000;
322 vidmem = (char *) 0xb8000;
326 lines = real_mode->screen_info.orig_video_lines;
327 cols = real_mode->screen_info.orig_video_cols;
329 free_mem_ptr = heap; /* Heap */
330 free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
332 if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
333 error("Destination address inappropriately aligned");
335 if (heap > 0x3fffffffffffUL)
336 error("Destination address too large");
338 if (heap > ((-__PAGE_OFFSET-(512<<20)-1) & 0x7fffffff))
339 error("Destination address too large");
341 #ifndef CONFIG_RELOCATABLE
342 if ((unsigned long)output != LOAD_PHYSICAL_ADDR)
343 error("Wrong destination address");
347 putstr("\nDecompressing Linux... ");
348 decompress(input_data, input_len, NULL, NULL, output, NULL, error);
351 putstr("done.\nBooting the kernel.\n");