xref: /linux/arch/powerpc/boot/main.c (revision f24e9f586b377749dff37554696cf3a105540c94)
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 
31 struct addr_range {
32 	unsigned long addr;
33 	unsigned long size;
34 	unsigned long memsize;
35 };
36 static struct addr_range vmlinux;
37 static struct addr_range vmlinuz;
38 static struct addr_range initrd;
39 
40 static unsigned long elfoffset;
41 static int is_64bit;
42 
43 /* scratch space for gunzip; 46912 is from zlib_inflate_workspacesize() */
44 static char scratch[46912];
45 static char elfheader[256];
46 
47 typedef void (*kernel_entry_t)(unsigned long, unsigned long, void *);
48 
49 #undef DEBUG
50 
51 #define HEAD_CRC	2
52 #define EXTRA_FIELD	4
53 #define ORIG_NAME	8
54 #define COMMENT		0x10
55 #define RESERVED	0xe0
56 
57 static void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp)
58 {
59 	z_stream s;
60 	int r, i, flags;
61 
62 	/* skip header */
63 	i = 10;
64 	flags = src[3];
65 	if (src[2] != Z_DEFLATED || (flags & RESERVED) != 0) {
66 		printf("bad gzipped data\n\r");
67 		exit();
68 	}
69 	if ((flags & EXTRA_FIELD) != 0)
70 		i = 12 + src[10] + (src[11] << 8);
71 	if ((flags & ORIG_NAME) != 0)
72 		while (src[i++] != 0)
73 			;
74 	if ((flags & COMMENT) != 0)
75 		while (src[i++] != 0)
76 			;
77 	if ((flags & HEAD_CRC) != 0)
78 		i += 2;
79 	if (i >= *lenp) {
80 		printf("gunzip: ran out of data in header\n\r");
81 		exit();
82 	}
83 
84 	if (zlib_inflate_workspacesize() > sizeof(scratch)) {
85 		printf("gunzip needs more mem\n");
86 		exit();
87 	}
88 	memset(&s, 0, sizeof(s));
89 	s.workspace = scratch;
90 	r = zlib_inflateInit2(&s, -MAX_WBITS);
91 	if (r != Z_OK) {
92 		printf("inflateInit2 returned %d\n\r", r);
93 		exit();
94 	}
95 	s.next_in = src + i;
96 	s.avail_in = *lenp - i;
97 	s.next_out = dst;
98 	s.avail_out = dstlen;
99 	r = zlib_inflate(&s, Z_FULL_FLUSH);
100 	if (r != Z_OK && r != Z_STREAM_END) {
101 		printf("inflate returned %d msg: %s\n\r", r, s.msg);
102 		exit();
103 	}
104 	*lenp = s.next_out - (unsigned char *) dst;
105 	zlib_inflateEnd(&s);
106 }
107 
108 static int is_elf64(void *hdr)
109 {
110 	Elf64_Ehdr *elf64 = hdr;
111 	Elf64_Phdr *elf64ph;
112 	unsigned int i;
113 
114 	if (!(elf64->e_ident[EI_MAG0]  == ELFMAG0	&&
115 	      elf64->e_ident[EI_MAG1]  == ELFMAG1	&&
116 	      elf64->e_ident[EI_MAG2]  == ELFMAG2	&&
117 	      elf64->e_ident[EI_MAG3]  == ELFMAG3	&&
118 	      elf64->e_ident[EI_CLASS] == ELFCLASS64	&&
119 	      elf64->e_ident[EI_DATA]  == ELFDATA2MSB	&&
120 	      elf64->e_type            == ET_EXEC	&&
121 	      elf64->e_machine         == EM_PPC64))
122 		return 0;
123 
124 	elf64ph = (Elf64_Phdr *)((unsigned long)elf64 +
125 				 (unsigned long)elf64->e_phoff);
126 	for (i = 0; i < (unsigned int)elf64->e_phnum; i++, elf64ph++)
127 		if (elf64ph->p_type == PT_LOAD)
128 			break;
129 	if (i >= (unsigned int)elf64->e_phnum)
130 		return 0;
131 
132 	elfoffset = (unsigned long)elf64ph->p_offset;
133 	vmlinux.size = (unsigned long)elf64ph->p_filesz + elfoffset;
134 	vmlinux.memsize = (unsigned long)elf64ph->p_memsz + elfoffset;
135 
136 	is_64bit = 1;
137 	return 1;
138 }
139 
140 static int is_elf32(void *hdr)
141 {
142 	Elf32_Ehdr *elf32 = hdr;
143 	Elf32_Phdr *elf32ph;
144 	unsigned int i;
145 
146 	if (!(elf32->e_ident[EI_MAG0]  == ELFMAG0	&&
147 	      elf32->e_ident[EI_MAG1]  == ELFMAG1	&&
148 	      elf32->e_ident[EI_MAG2]  == ELFMAG2	&&
149 	      elf32->e_ident[EI_MAG3]  == ELFMAG3	&&
150 	      elf32->e_ident[EI_CLASS] == ELFCLASS32	&&
151 	      elf32->e_ident[EI_DATA]  == ELFDATA2MSB	&&
152 	      elf32->e_type            == ET_EXEC	&&
153 	      elf32->e_machine         == EM_PPC))
154 		return 0;
155 
156 	elf32 = (Elf32_Ehdr *)elfheader;
157 	elf32ph = (Elf32_Phdr *) ((unsigned long)elf32 + elf32->e_phoff);
158 	for (i = 0; i < elf32->e_phnum; i++, elf32ph++)
159 		if (elf32ph->p_type == PT_LOAD)
160 			break;
161 	if (i >= elf32->e_phnum)
162 		return 0;
163 
164 	elfoffset = elf32ph->p_offset;
165 	vmlinux.size = elf32ph->p_filesz + elf32ph->p_offset;
166 	vmlinux.memsize = elf32ph->p_memsz + elf32ph->p_offset;
167 	return 1;
168 }
169 
170 static void prep_kernel(unsigned long *a1, unsigned long *a2)
171 {
172 	int len;
173 
174 	vmlinuz.addr = (unsigned long)_vmlinux_start;
175 	vmlinuz.size = (unsigned long)(_vmlinux_end - _vmlinux_start);
176 
177 	/* gunzip the ELF header of the kernel */
178 	if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
179 		len = vmlinuz.size;
180 		gunzip(elfheader, sizeof(elfheader),
181 				(unsigned char *)vmlinuz.addr, &len);
182 	} else
183 		memcpy(elfheader, (const void *)vmlinuz.addr,
184 		       sizeof(elfheader));
185 
186 	if (!is_elf64(elfheader) && !is_elf32(elfheader)) {
187 		printf("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
188 		exit();
189 	}
190 	if (platform_ops.image_hdr)
191 		platform_ops.image_hdr(elfheader);
192 
193 	/* We need to alloc the memsize plus the file offset since gzip
194 	 * will expand the header (file offset), then the kernel, then
195 	 * possible rubbish we don't care about. But the kernel bss must
196 	 * be claimed (it will be zero'd by the kernel itself)
197 	 */
198 	printf("Allocating 0x%lx bytes for kernel ...\n\r", vmlinux.memsize);
199 	vmlinux.addr = (unsigned long)malloc(vmlinux.memsize);
200 	if (vmlinux.addr == 0) {
201 		printf("Can't allocate memory for kernel image !\n\r");
202 		exit();
203 	}
204 
205 	/*
206 	 * Now we try to alloc memory for the initrd (and copy it there)
207 	 */
208 	initrd.size = (unsigned long)(_initrd_end - _initrd_start);
209 	initrd.memsize = initrd.size;
210 	if ( initrd.size > 0 ) {
211 		printf("Allocating 0x%lx bytes for initrd ...\n\r",
212 		       initrd.size);
213 		initrd.addr = (unsigned long)malloc((u32)initrd.size);
214 		if (initrd.addr == 0) {
215 			printf("Can't allocate memory for initial "
216 					"ramdisk !\n\r");
217 			exit();
218 		}
219 		*a1 = initrd.addr;
220 		*a2 = initrd.size;
221 		printf("initial ramdisk moving 0x%lx <- 0x%lx "
222 			"(0x%lx bytes)\n\r", initrd.addr,
223 			(unsigned long)_initrd_start, initrd.size);
224 		memmove((void *)initrd.addr, (void *)_initrd_start,
225 			initrd.size);
226 		printf("initrd head: 0x%lx\n\r",
227 				*((unsigned long *)initrd.addr));
228 	}
229 
230 	/* Eventually gunzip the kernel */
231 	if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
232 		printf("gunzipping (0x%lx <- 0x%lx:0x%0lx)...",
233 		       vmlinux.addr, vmlinuz.addr, vmlinuz.addr+vmlinuz.size);
234 		len = vmlinuz.size;
235 		gunzip((void *)vmlinux.addr, vmlinux.memsize,
236 			(unsigned char *)vmlinuz.addr, &len);
237 		printf("done 0x%lx bytes\n\r", len);
238 	} else {
239 		memmove((void *)vmlinux.addr,(void *)vmlinuz.addr,
240 			vmlinuz.size);
241 	}
242 
243 	/* Skip over the ELF header */
244 #ifdef DEBUG
245 	printf("... skipping 0x%lx bytes of ELF header\n\r",
246 			elfoffset);
247 #endif
248 	vmlinux.addr += elfoffset;
249 
250 	flush_cache((void *)vmlinux.addr, vmlinux.size);
251 }
252 
253 void __attribute__ ((weak)) ft_init(void *dt_blob)
254 {
255 }
256 
257 /* A buffer that may be edited by tools operating on a zImage binary so as to
258  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
259  * The buffer is put in it's own section so that tools may locate it easier.
260  */
261 static char builtin_cmdline[COMMAND_LINE_SIZE]
262 	__attribute__((__section__("__builtin_cmdline")));
263 
264 static void get_cmdline(char *buf, int size)
265 {
266 	void *devp;
267 	int len = strlen(builtin_cmdline);
268 
269 	buf[0] = '\0';
270 
271 	if (len > 0) { /* builtin_cmdline overrides dt's /chosen/bootargs */
272 		len = min(len, size-1);
273 		strncpy(buf, builtin_cmdline, len);
274 		buf[len] = '\0';
275 	}
276 	else if ((devp = finddevice("/chosen")))
277 		getprop(devp, "bootargs", buf, size);
278 }
279 
280 static void set_cmdline(char *buf)
281 {
282 	void *devp;
283 
284 	if ((devp = finddevice("/chosen")))
285 		setprop(devp, "bootargs", buf, strlen(buf) + 1);
286 }
287 
288 /* Section where ft can be tacked on after zImage is built */
289 union blobspace {
290 	struct boot_param_header hdr;
291 	char space[8*1024];
292 } dt_blob __attribute__((__section__("__builtin_ft")));
293 
294 struct platform_ops platform_ops;
295 struct dt_ops dt_ops;
296 struct console_ops console_ops;
297 
298 void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
299 {
300 	int have_dt = 0;
301 	kernel_entry_t kentry;
302 	char cmdline[COMMAND_LINE_SIZE];
303 
304 	memset(__bss_start, 0, _end - __bss_start);
305 	memset(&platform_ops, 0, sizeof(platform_ops));
306 	memset(&dt_ops, 0, sizeof(dt_ops));
307 	memset(&console_ops, 0, sizeof(console_ops));
308 
309 	/* Override the dt_ops and device tree if there was an flat dev
310 	 * tree attached to the zImage.
311 	 */
312 	if (dt_blob.hdr.magic == OF_DT_HEADER) {
313 		have_dt = 1;
314 		ft_init(&dt_blob);
315 	}
316 
317 	if (platform_init(promptr))
318 		exit();
319 	if (console_ops.open && (console_ops.open() < 0))
320 		exit();
321 	if (platform_ops.fixups)
322 		platform_ops.fixups();
323 
324 	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
325 	       _start, sp);
326 
327 	prep_kernel(&a1, &a2);
328 
329 	/* If cmdline came from zimage wrapper or if we can edit the one
330 	 * in the dt, print it out and edit it, if possible.
331 	 */
332 	if ((strlen(builtin_cmdline) > 0) || console_ops.edit_cmdline) {
333 		get_cmdline(cmdline, COMMAND_LINE_SIZE);
334 		printf("\n\rLinux/PowerPC load: %s", cmdline);
335 		if (console_ops.edit_cmdline)
336 			console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
337 		printf("\n\r");
338 		set_cmdline(cmdline);
339 	}
340 
341 	if (console_ops.close)
342 		console_ops.close();
343 
344 	kentry = (kernel_entry_t) vmlinux.addr;
345 	if (have_dt)
346 		kentry(dt_ops.ft_addr(), 0, NULL);
347 	else
348 		/* XXX initrd addr/size should be passed in properties */
349 		kentry(a1, a2, promptr);
350 
351 	/* console closed so printf below may not work */
352 	printf("Error: Linux kernel returned to zImage boot wrapper!\n\r");
353 	exit();
354 }
355