xref: /linux/arch/powerpc/boot/main.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
1 /*
2  * Copyright (C) Paul Mackerras 1997.
3  *
4  * Updates for PPC64 by Todd Inglett, Dave Engebretsen & Peter Bergner.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 #include <stdarg.h>
12 #include <stddef.h>
13 #include "elf.h"
14 #include "page.h"
15 #include "string.h"
16 #include "stdio.h"
17 #include "zlib.h"
18 #include "ops.h"
19 #include "flatdevtree.h"
20 
21 extern void flush_cache(void *, unsigned long);
22 
23 extern char _start[];
24 extern char __bss_start[];
25 extern char _end[];
26 extern char _vmlinux_start[];
27 extern char _vmlinux_end[];
28 extern char _initrd_start[];
29 extern char _initrd_end[];
30 extern char _dtb_start[];
31 extern char _dtb_end[];
32 
33 struct addr_range {
34 	unsigned long addr;
35 	unsigned long size;
36 	unsigned long memsize;
37 };
38 static struct addr_range vmlinux;
39 static struct addr_range vmlinuz;
40 static struct addr_range initrd;
41 
42 static unsigned long elfoffset;
43 static int is_64bit;
44 
45 /* scratch space for gunzip; 46912 is from zlib_inflate_workspacesize() */
46 static char scratch[46912];
47 static char elfheader[256];
48 
49 typedef void (*kernel_entry_t)(unsigned long, unsigned long, void *);
50 
51 #undef DEBUG
52 
53 #define HEAD_CRC	2
54 #define EXTRA_FIELD	4
55 #define ORIG_NAME	8
56 #define COMMENT		0x10
57 #define RESERVED	0xe0
58 
59 static void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp)
60 {
61 	z_stream s;
62 	int r, i, flags;
63 
64 	/* skip header */
65 	i = 10;
66 	flags = src[3];
67 	if (src[2] != Z_DEFLATED || (flags & RESERVED) != 0) {
68 		printf("bad gzipped data\n\r");
69 		exit();
70 	}
71 	if ((flags & EXTRA_FIELD) != 0)
72 		i = 12 + src[10] + (src[11] << 8);
73 	if ((flags & ORIG_NAME) != 0)
74 		while (src[i++] != 0)
75 			;
76 	if ((flags & COMMENT) != 0)
77 		while (src[i++] != 0)
78 			;
79 	if ((flags & HEAD_CRC) != 0)
80 		i += 2;
81 	if (i >= *lenp) {
82 		printf("gunzip: ran out of data in header\n\r");
83 		exit();
84 	}
85 
86 	if (zlib_inflate_workspacesize() > sizeof(scratch)) {
87 		printf("gunzip needs more mem\n");
88 		exit();
89 	}
90 	memset(&s, 0, sizeof(s));
91 	s.workspace = scratch;
92 	r = zlib_inflateInit2(&s, -MAX_WBITS);
93 	if (r != Z_OK) {
94 		printf("inflateInit2 returned %d\n\r", r);
95 		exit();
96 	}
97 	s.next_in = src + i;
98 	s.avail_in = *lenp - i;
99 	s.next_out = dst;
100 	s.avail_out = dstlen;
101 	r = zlib_inflate(&s, Z_FULL_FLUSH);
102 	if (r != Z_OK && r != Z_STREAM_END) {
103 		printf("inflate returned %d msg: %s\n\r", r, s.msg);
104 		exit();
105 	}
106 	*lenp = s.next_out - (unsigned char *) dst;
107 	zlib_inflateEnd(&s);
108 }
109 
110 static int is_elf64(void *hdr)
111 {
112 	Elf64_Ehdr *elf64 = hdr;
113 	Elf64_Phdr *elf64ph;
114 	unsigned int i;
115 
116 	if (!(elf64->e_ident[EI_MAG0]  == ELFMAG0	&&
117 	      elf64->e_ident[EI_MAG1]  == ELFMAG1	&&
118 	      elf64->e_ident[EI_MAG2]  == ELFMAG2	&&
119 	      elf64->e_ident[EI_MAG3]  == ELFMAG3	&&
120 	      elf64->e_ident[EI_CLASS] == ELFCLASS64	&&
121 	      elf64->e_ident[EI_DATA]  == ELFDATA2MSB	&&
122 	      elf64->e_type            == ET_EXEC	&&
123 	      elf64->e_machine         == EM_PPC64))
124 		return 0;
125 
126 	elf64ph = (Elf64_Phdr *)((unsigned long)elf64 +
127 				 (unsigned long)elf64->e_phoff);
128 	for (i = 0; i < (unsigned int)elf64->e_phnum; i++, elf64ph++)
129 		if (elf64ph->p_type == PT_LOAD)
130 			break;
131 	if (i >= (unsigned int)elf64->e_phnum)
132 		return 0;
133 
134 	elfoffset = (unsigned long)elf64ph->p_offset;
135 	vmlinux.size = (unsigned long)elf64ph->p_filesz + elfoffset;
136 	vmlinux.memsize = (unsigned long)elf64ph->p_memsz + elfoffset;
137 
138 	is_64bit = 1;
139 	return 1;
140 }
141 
142 static int is_elf32(void *hdr)
143 {
144 	Elf32_Ehdr *elf32 = hdr;
145 	Elf32_Phdr *elf32ph;
146 	unsigned int i;
147 
148 	if (!(elf32->e_ident[EI_MAG0]  == ELFMAG0	&&
149 	      elf32->e_ident[EI_MAG1]  == ELFMAG1	&&
150 	      elf32->e_ident[EI_MAG2]  == ELFMAG2	&&
151 	      elf32->e_ident[EI_MAG3]  == ELFMAG3	&&
152 	      elf32->e_ident[EI_CLASS] == ELFCLASS32	&&
153 	      elf32->e_ident[EI_DATA]  == ELFDATA2MSB	&&
154 	      elf32->e_type            == ET_EXEC	&&
155 	      elf32->e_machine         == EM_PPC))
156 		return 0;
157 
158 	elf32 = (Elf32_Ehdr *)elfheader;
159 	elf32ph = (Elf32_Phdr *) ((unsigned long)elf32 + elf32->e_phoff);
160 	for (i = 0; i < elf32->e_phnum; i++, elf32ph++)
161 		if (elf32ph->p_type == PT_LOAD)
162 			break;
163 	if (i >= elf32->e_phnum)
164 		return 0;
165 
166 	elfoffset = elf32ph->p_offset;
167 	vmlinux.size = elf32ph->p_filesz + elf32ph->p_offset;
168 	vmlinux.memsize = elf32ph->p_memsz + elf32ph->p_offset;
169 	return 1;
170 }
171 
172 static void prep_kernel(unsigned long a1, unsigned long a2)
173 {
174 	int len;
175 
176 	vmlinuz.addr = (unsigned long)_vmlinux_start;
177 	vmlinuz.size = (unsigned long)(_vmlinux_end - _vmlinux_start);
178 
179 	/* gunzip the ELF header of the kernel */
180 	if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
181 		len = vmlinuz.size;
182 		gunzip(elfheader, sizeof(elfheader),
183 				(unsigned char *)vmlinuz.addr, &len);
184 	} else
185 		memcpy(elfheader, (const void *)vmlinuz.addr,
186 		       sizeof(elfheader));
187 
188 	if (!is_elf64(elfheader) && !is_elf32(elfheader)) {
189 		printf("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
190 		exit();
191 	}
192 	if (platform_ops.image_hdr)
193 		platform_ops.image_hdr(elfheader);
194 
195 	/* We need to alloc the memsize plus the file offset since gzip
196 	 * will expand the header (file offset), then the kernel, then
197 	 * possible rubbish we don't care about. But the kernel bss must
198 	 * be claimed (it will be zero'd by the kernel itself)
199 	 */
200 	printf("Allocating 0x%lx bytes for kernel ...\n\r", vmlinux.memsize);
201 	vmlinux.addr = (unsigned long)malloc(vmlinux.memsize);
202 	if (vmlinux.addr == 0) {
203 		printf("Can't allocate memory for kernel image !\n\r");
204 		exit();
205 	}
206 
207 	/*
208 	 * Now find the initrd
209 	 *
210 	 * First see if we have an image attached to us.  If so
211 	 * allocate memory for it and copy it there.
212 	 */
213 	initrd.size = (unsigned long)(_initrd_end - _initrd_start);
214 	initrd.memsize = initrd.size;
215 	if (initrd.size > 0) {
216 		printf("Allocating 0x%lx bytes for initrd ...\n\r",
217 		       initrd.size);
218 		initrd.addr = (unsigned long)malloc((u32)initrd.size);
219 		if (initrd.addr == 0) {
220 			printf("Can't allocate memory for initial "
221 					"ramdisk !\n\r");
222 			exit();
223 		}
224 		printf("initial ramdisk moving 0x%lx <- 0x%lx "
225 			"(0x%lx bytes)\n\r", initrd.addr,
226 			(unsigned long)_initrd_start, initrd.size);
227 		memmove((void *)initrd.addr, (void *)_initrd_start,
228 			initrd.size);
229 		printf("initrd head: 0x%lx\n\r",
230 				*((unsigned long *)initrd.addr));
231 	} else if (a2 != 0) {
232 		/* Otherwise, see if yaboot or another loader gave us an initrd */
233 		initrd.addr = a1;
234 		initrd.memsize = initrd.size = a2;
235 		printf("Using loader supplied initrd at 0x%lx (0x%lx bytes)\n\r",
236 		       initrd.addr, initrd.size);
237 	}
238 
239 	/* Eventually gunzip the kernel */
240 	if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
241 		printf("gunzipping (0x%lx <- 0x%lx:0x%0lx)...",
242 		       vmlinux.addr, vmlinuz.addr, vmlinuz.addr+vmlinuz.size);
243 		len = vmlinuz.size;
244 		gunzip((void *)vmlinux.addr, vmlinux.memsize,
245 			(unsigned char *)vmlinuz.addr, &len);
246 		printf("done 0x%lx bytes\n\r", len);
247 	} else {
248 		memmove((void *)vmlinux.addr,(void *)vmlinuz.addr,
249 			vmlinuz.size);
250 	}
251 
252 	/* Skip over the ELF header */
253 #ifdef DEBUG
254 	printf("... skipping 0x%lx bytes of ELF header\n\r",
255 			elfoffset);
256 #endif
257 	vmlinux.addr += elfoffset;
258 
259 	flush_cache((void *)vmlinux.addr, vmlinux.size);
260 }
261 
262 /* A buffer that may be edited by tools operating on a zImage binary so as to
263  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
264  * The buffer is put in it's own section so that tools may locate it easier.
265  */
266 static char builtin_cmdline[COMMAND_LINE_SIZE]
267 	__attribute__((__section__("__builtin_cmdline")));
268 
269 static void get_cmdline(char *buf, int size)
270 {
271 	void *devp;
272 	int len = strlen(builtin_cmdline);
273 
274 	buf[0] = '\0';
275 
276 	if (len > 0) { /* builtin_cmdline overrides dt's /chosen/bootargs */
277 		len = min(len, size-1);
278 		strncpy(buf, builtin_cmdline, len);
279 		buf[len] = '\0';
280 	}
281 	else if ((devp = finddevice("/chosen")))
282 		getprop(devp, "bootargs", buf, size);
283 }
284 
285 static void set_cmdline(char *buf)
286 {
287 	void *devp;
288 
289 	if ((devp = finddevice("/chosen")))
290 		setprop(devp, "bootargs", buf, strlen(buf) + 1);
291 }
292 
293 struct platform_ops platform_ops;
294 struct dt_ops dt_ops;
295 struct console_ops console_ops;
296 
297 void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
298 {
299 	kernel_entry_t kentry;
300 	char cmdline[COMMAND_LINE_SIZE];
301 	unsigned long ft_addr = 0;
302 
303 	memset(__bss_start, 0, _end - __bss_start);
304 	memset(&platform_ops, 0, sizeof(platform_ops));
305 	memset(&dt_ops, 0, sizeof(dt_ops));
306 	memset(&console_ops, 0, sizeof(console_ops));
307 
308 	if (platform_init(promptr, _dtb_start, _dtb_end))
309 		exit();
310 	if (console_ops.open && (console_ops.open() < 0))
311 		exit();
312 	if (platform_ops.fixups)
313 		platform_ops.fixups();
314 
315 	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
316 	       _start, sp);
317 
318 	prep_kernel(a1, a2);
319 
320 	/* If cmdline came from zimage wrapper or if we can edit the one
321 	 * in the dt, print it out and edit it, if possible.
322 	 */
323 	if ((strlen(builtin_cmdline) > 0) || console_ops.edit_cmdline) {
324 		get_cmdline(cmdline, COMMAND_LINE_SIZE);
325 		printf("\n\rLinux/PowerPC load: %s", cmdline);
326 		if (console_ops.edit_cmdline)
327 			console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
328 		printf("\n\r");
329 		set_cmdline(cmdline);
330 	}
331 
332 	printf("Finalizing device tree...");
333 	if (dt_ops.finalize)
334 		ft_addr = dt_ops.finalize();
335 	if (ft_addr)
336 		printf(" flat tree at 0x%lx\n\r", ft_addr);
337 	else
338 		printf(" using OF tree (promptr=%p)\n\r", promptr);
339 
340 	if (console_ops.close)
341 		console_ops.close();
342 
343 	kentry = (kernel_entry_t) vmlinux.addr;
344 	if (ft_addr)
345 		kentry(ft_addr, 0, NULL);
346 	else
347 		/* XXX initrd addr/size should be passed in properties */
348 		kentry(initrd.addr, initrd.size, promptr);
349 
350 	/* console closed so printf below may not work */
351 	printf("Error: Linux kernel returned to zImage boot wrapper!\n\r");
352 	exit();
353 }
354