summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/boot/main.c
blob: 816446f0e497a64dda37c15f27ce0b6e4560a698 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
/*
 * Copyright (C) Paul Mackerras 1997.
 *
 * Updates for PPC64 by Todd Inglett, Dave Engebretsen & Peter Bergner.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#include <stdarg.h>
#include <stddef.h>
#include "elf.h"
#include "page.h"
#include "string.h"
#include "stdio.h"
#include "prom.h"
#include "zlib.h"

extern void flush_cache(void *, unsigned long);


/* Value picked to match that used by yaboot */
#define PROG_START	0x01400000	/* only used on 64-bit systems */
#define RAM_END		(512<<20)	/* Fixme: use OF */
#define	ONE_MB		0x100000

extern char _start[];
extern char __bss_start[];
extern char _end[];
extern char _vmlinux_start[];
extern char _vmlinux_end[];
extern char _initrd_start[];
extern char _initrd_end[];

struct addr_range {
	unsigned long addr;
	unsigned long size;
	unsigned long memsize;
};
static struct addr_range vmlinux;
static struct addr_range vmlinuz;
static struct addr_range initrd;

static unsigned long elfoffset;

static char scratch[46912];	/* scratch space for gunzip, from zlib_inflate_workspacesize() */
static char elfheader[256];


typedef void (*kernel_entry_t)( unsigned long,
                                unsigned long,
                                void *,
				void *);


#undef DEBUG

static unsigned long claim_base;

#define HEAD_CRC	2
#define EXTRA_FIELD	4
#define ORIG_NAME	8
#define COMMENT		0x10
#define RESERVED	0xe0

static void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp)
{
	z_stream s;
	int r, i, flags;

	/* skip header */
	i = 10;
	flags = src[3];
	if (src[2] != Z_DEFLATED || (flags & RESERVED) != 0) {
		printf("bad gzipped data\n\r");
		exit();
	}
	if ((flags & EXTRA_FIELD) != 0)
		i = 12 + src[10] + (src[11] << 8);
	if ((flags & ORIG_NAME) != 0)
		while (src[i++] != 0)
			;
	if ((flags & COMMENT) != 0)
		while (src[i++] != 0)
			;
	if ((flags & HEAD_CRC) != 0)
		i += 2;
	if (i >= *lenp) {
		printf("gunzip: ran out of data in header\n\r");
		exit();
	}

	if (zlib_inflate_workspacesize() > sizeof(scratch)) {
		printf("gunzip needs more mem\n");
		exit();
	}
	memset(&s, 0, sizeof(s));
	s.workspace = scratch;
	r = zlib_inflateInit2(&s, -MAX_WBITS);
	if (r != Z_OK) {
		printf("inflateInit2 returned %d\n\r", r);
		exit();
	}
	s.next_in = src + i;
	s.avail_in = *lenp - i;
	s.next_out = dst;
	s.avail_out = dstlen;
	r = zlib_inflate(&s, Z_FULL_FLUSH);
	if (r != Z_OK && r != Z_STREAM_END) {
		printf("inflate returned %d msg: %s\n\r", r, s.msg);
		exit();
	}
	*lenp = s.next_out - (unsigned char *) dst;
	zlib_inflateEnd(&s);
}

static unsigned long try_claim(unsigned long size)
{
	unsigned long addr = 0;

	for(; claim_base < RAM_END; claim_base += ONE_MB) {
#ifdef DEBUG
		printf("    trying: 0x%08lx\n\r", claim_base);
#endif
		addr = (unsigned long)claim(claim_base, size, 0);
		if ((void *)addr != (void *)-1)
			break;
	}
	if (addr == 0)
		return 0;
	claim_base = PAGE_ALIGN(claim_base + size);
	return addr;
}

static int is_elf64(void *hdr)
{
	Elf64_Ehdr *elf64 = hdr;
	Elf64_Phdr *elf64ph;
	unsigned int i;

	if (!(elf64->e_ident[EI_MAG0]  == ELFMAG0	&&
	      elf64->e_ident[EI_MAG1]  == ELFMAG1	&&
	      elf64->e_ident[EI_MAG2]  == ELFMAG2	&&
	      elf64->e_ident[EI_MAG3]  == ELFMAG3	&&
	      elf64->e_ident[EI_CLASS] == ELFCLASS64	&&
	      elf64->e_ident[EI_DATA]  == ELFDATA2MSB	&&
	      elf64->e_type            == ET_EXEC	&&
	      elf64->e_machine         == EM_PPC64))
		return 0;

	elf64ph = (Elf64_Phdr *)((unsigned long)elf64 +
				 (unsigned long)elf64->e_phoff);
	for (i = 0; i < (unsigned int)elf64->e_phnum; i++, elf64ph++)
		if (elf64ph->p_type == PT_LOAD)
			break;
	if (i >= (unsigned int)elf64->e_phnum)
		return 0;

	elfoffset = (unsigned long)elf64ph->p_offset;
	vmlinux.size = (unsigned long)elf64ph->p_filesz + elfoffset;
	vmlinux.memsize = (unsigned long)elf64ph->p_memsz + elfoffset;

#if defined(PROG_START)
	/*
	 * Maintain a "magic" minimum address. This keeps some older
	 * firmware platforms running.
	 */

	if (claim_base < PROG_START)
		claim_base = PROG_START;
#endif

	return 1;
}

static int is_elf32(void *hdr)
{
	Elf32_Ehdr *elf32 = hdr;
	Elf32_Phdr *elf32ph;
	unsigned int i;

	if (!(elf32->e_ident[EI_MAG0]  == ELFMAG0	&&
	      elf32->e_ident[EI_MAG1]  == ELFMAG1	&&
	      elf32->e_ident[EI_MAG2]  == ELFMAG2	&&
	      elf32->e_ident[EI_MAG3]  == ELFMAG3	&&
	      elf32->e_ident[EI_CLASS] == ELFCLASS32	&&
	      elf32->e_ident[EI_DATA]  == ELFDATA2MSB	&&
	      elf32->e_type            == ET_EXEC	&&
	      elf32->e_machine         == EM_PPC))
		return 0;

	elf32 = (Elf32_Ehdr *)elfheader;
	elf32ph = (Elf32_Phdr *) ((unsigned long)elf32 + elf32->e_phoff);
	for (i = 0; i < elf32->e_phnum; i++, elf32ph++)
		if (elf32ph->p_type == PT_LOAD)
			break;
	if (i >= elf32->e_phnum)
		return 0;

	elfoffset = elf32ph->p_offset;
	vmlinux.size = elf32ph->p_filesz + elf32ph->p_offset;
	vmlinux.memsize = elf32ph->p_memsz + elf32ph->p_offset;
	return 1;
}

void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
{
	int len;
	kernel_entry_t kernel_entry;

	memset(__bss_start, 0, _end - __bss_start);

	prom = (int (*)(void *)) promptr;
	chosen_handle = finddevice("/chosen");
	if (chosen_handle == (void *) -1)
		exit();
	if (getprop(chosen_handle, "stdout", &stdout, sizeof(stdout)) != 4)
		exit();

	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r", _start, sp);

	/*
	 * The first available claim_base must be above the end of the
	 * the loaded kernel wrapper file (_start to _end includes the
	 * initrd image if it is present) and rounded up to a nice
	 * 1 MB boundary for good measure.
	 */

	claim_base = _ALIGN_UP((unsigned long)_end, ONE_MB);

	vmlinuz.addr = (unsigned long)_vmlinux_start;
	vmlinuz.size = (unsigned long)(_vmlinux_end - _vmlinux_start);

	/* gunzip the ELF header of the kernel */
	if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
		len = vmlinuz.size;
		gunzip(elfheader, sizeof(elfheader),
				(unsigned char *)vmlinuz.addr, &len);
	} else
		memcpy(elfheader, (const void *)vmlinuz.addr, sizeof(elfheader));

	if (!is_elf64(elfheader) && !is_elf32(elfheader)) {
		printf("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
		exit();
	}

	/* We need to claim the memsize plus the file offset since gzip
	 * will expand the header (file offset), then the kernel, then
	 * possible rubbish we don't care about. But the kernel bss must
	 * be claimed (it will be zero'd by the kernel itself)
	 */
	printf("Allocating 0x%lx bytes for kernel ...\n\r", vmlinux.memsize);
	vmlinux.addr = try_claim(vmlinux.memsize);
	if (vmlinux.addr == 0) {
		printf("Can't allocate memory for kernel image !\n\r");
		exit();
	}

	/*
	 * Now we try to claim memory for the initrd (and copy it there)
	 */
	initrd.size = (unsigned long)(_initrd_end - _initrd_start);
	initrd.memsize = initrd.size;
	if ( initrd.size > 0 ) {
		printf("Allocating 0x%lx bytes for initrd ...\n\r", initrd.size);
		initrd.addr = try_claim(initrd.size);
		if (initrd.addr == 0) {
			printf("Can't allocate memory for initial ramdisk !\n\r");
			exit();
		}
		a1 = initrd.addr;
		a2 = initrd.size;
		printf("initial ramdisk moving 0x%lx <- 0x%lx (0x%lx bytes)\n\r",
		       initrd.addr, (unsigned long)_initrd_start, initrd.size);
		memmove((void *)initrd.addr, (void *)_initrd_start, initrd.size);
		printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd.addr));
	}

	/* Eventually gunzip the kernel */
	if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
		printf("gunzipping (0x%lx <- 0x%lx:0x%0lx)...",
		       vmlinux.addr, vmlinuz.addr, vmlinuz.addr+vmlinuz.size);
		len = vmlinuz.size;
		gunzip((void *)vmlinux.addr, vmlinux.memsize,
			(unsigned char *)vmlinuz.addr, &len);
		printf("done 0x%lx bytes\n\r", len);
	} else {
		memmove((void *)vmlinux.addr,(void *)vmlinuz.addr,vmlinuz.size);
	}

	/* Skip over the ELF header */
#ifdef DEBUG
	printf("... skipping 0x%lx bytes of ELF header\n\r",
			elfoffset);
#endif
	vmlinux.addr += elfoffset;

	flush_cache((void *)vmlinux.addr, vmlinux.size);

	kernel_entry = (kernel_entry_t)vmlinux.addr;
#ifdef DEBUG
	printf( "kernel:\n\r"
		"        entry addr = 0x%lx\n\r"
		"        a1         = 0x%lx,\n\r"
		"        a2         = 0x%lx,\n\r"
		"        prom       = 0x%lx,\n\r"
		"        bi_recs    = 0x%lx,\n\r",
		(unsigned long)kernel_entry, a1, a2,
		(unsigned long)prom, NULL);
#endif

	kernel_entry(a1, a2, prom, NULL);

	printf("Error: Linux kernel returned to zImage bootloader!\n\r");

	exit();
}

OpenPOWER on IntegriCloud