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 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 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 void *malloc(size_t size)
208 {
209 	return malloc_gzip(size);
210 }
211 
212 #undef free
free(void * ptr)213 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 unsigned long 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