summaryrefslogtreecommitdiff
path: root/arch/i386/lib/zimage.c
blob: 0c420726912c120b5a263b7e3b3c165d5af601e6 (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
/*
 * (C) Copyright 2002
 * Daniel Engström, Omicron Ceti AB, daniel@omicron.se
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

/*
 * Linux i386 zImage and bzImage loading
 *
 * based on the procdure described in
 * linux/Documentation/i386/boot.txt
 */

#include <common.h>
#include <asm/io.h>
#include <asm/ptrace.h>
#include <asm/zimage.h>
#include <asm/realmode.h>
#include <asm/byteorder.h>
#include <asm/bootparam.h>
#include <asm/ic/sc520.h>

/*
 * Memory lay-out:
 *
 * relative to setup_base (which is 0x90000 currently)
 *
 *	0x0000-0x7FFF	Real mode kernel
 *	0x8000-0x8FFF	Stack and heap
 *	0x9000-0x90FF	Kernel command line
 */
#define DEFAULT_SETUP_BASE  0x90000
#define COMMAND_LINE_OFFSET 0x9000
#define HEAP_END_OFFSET     0x8e00

#define COMMAND_LINE_SIZE   2048

static void build_command_line(char *command_line, int auto_boot)
{
	char *env_command_line;

	command_line[0] = '\0';

	env_command_line =  getenv("bootargs");

	/* set console= argument if we use a serial console */
	if (NULL == strstr(env_command_line, "console=")) {
		if (0==strcmp(getenv("stdout"), "serial")) {

			/* We seem to use serial console */
			sprintf(command_line, "console=ttyS0,%s ",
				 getenv("baudrate"));
		}
	}

	if (auto_boot) {
		strcat(command_line, "auto ");
	}

	if (NULL != env_command_line) {
		strcat(command_line, env_command_line);
	}


	printf("Kernel command line: \"%s\"\n", command_line);
}

void *load_zimage(char *image, unsigned long kernel_size,
		  unsigned long initrd_addr, unsigned long initrd_size,
		  int auto_boot)
{
	void *setup_base;
	int setup_size;
	int bootproto;
	int big_image;
	void *load_address;

	struct setup_header *hdr = (struct setup_header *)(image + SETUP_SECTS_OFF);

	setup_base = (void*)DEFAULT_SETUP_BASE;	/* base address for real-mode segment */

	if (KERNEL_MAGIC != hdr->boot_flag) {
		printf("Error: Invalid Boot Flag (found 0x%04x, expected 0x%04x)\n",
				hdr->boot_flag, KERNEL_MAGIC);
		return 0;
	} else {
		printf("Valid Boot Flag\n");
	}

	/* determine boot protocol version */
	if (KERNEL_V2_MAGIC == hdr->header) {
		printf("Magic signature found\n");

		bootproto = hdr->version;
	} else {
		/* Very old kernel */
		printf("Magic signature not found\n");
		bootproto = 0x0100;
	}

	/* determine size of setup */
	if (0 == hdr->setup_sects) {
		printf("Setup Sectors = 0 (defaulting to 4)\n");
		setup_size = 5 * 512;
	} else {
		setup_size = (hdr->setup_sects + 1) * 512;
	}

	printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);

	if (setup_size > SETUP_MAX_SIZE) {
		printf("Error: Setup is too large (%d bytes)\n", setup_size);
	}

	/* Determine image type */
	big_image = (bootproto >= 0x0200) && (hdr->loadflags & BIG_KERNEL_FLAG);

	/* Determine load address */
	load_address = (void*)(big_image ? BZIMAGE_LOAD_ADDR : ZIMAGE_LOAD_ADDR);

	/* load setup */
	printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n", (ulong)setup_base, setup_size);
	memmove(setup_base, image, setup_size);

	printf("Using boot protocol version %x.%02x\n",
	       (bootproto & 0xff00) >> 8, bootproto & 0xff);

	if (bootproto == 0x0100) {

		*(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
		*(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET;

		/* A very old kernel MUST have its real-mode code
		 * loaded at 0x90000 */

		if ((u32)setup_base != 0x90000) {
			/* Copy the real-mode kernel */
			memmove((void*)0x90000, setup_base, setup_size);
			/* Copy the command line */
			memmove((void*)0x99000, setup_base+COMMAND_LINE_OFFSET,
			       COMMAND_LINE_SIZE);

			setup_base = (void*)0x90000;		 /* Relocated */
		}

		/* It is recommended to clear memory up to the 32K mark */
		memset((void*)0x90000 + setup_size, 0, SETUP_MAX_SIZE-setup_size);
	}

	/* We are now setting up the real-mode version of the header */
	hdr = (struct setup_header *)(setup_base + SETUP_SECTS_OFF);

	if (bootproto >= 0x0200) {
		hdr->type_of_loader = 8;

		if (hdr->setup_sects >= 15)
			printf("Linux kernel version %s\n", (char *)
					(setup_base + (hdr->kernel_version + 0x200)));
		else
			printf("Setup Sectors < 15 - Cannot print kernel version.\n");

		if (initrd_addr) {
			printf("Initial RAM disk at linear address 0x%08lx, size %ld bytes\n",
			       initrd_addr, initrd_size);

			hdr->ramdisk_image = initrd_addr;
			hdr->ramdisk_size = initrd_size;
		}
	}

	if (bootproto >= 0x0201) {
		hdr->heap_end_ptr = HEAP_END_OFFSET;
		hdr->loadflags |= HEAP_FLAG;
	}

	if (bootproto >= 0x0202) {
		hdr->cmd_line_ptr = (u32)setup_base + COMMAND_LINE_OFFSET;
	} else if (bootproto >= 0x0200) {

		*(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
		*(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET;

		hdr->setup_move_size = 0x9100;
	}

	if (bootproto >= 0x0204)
		kernel_size = hdr->syssize * 16;
	else
		kernel_size -= setup_size;


	if (big_image) {
		if ((kernel_size) > BZIMAGE_MAX_SIZE) {
			printf("Error: bzImage kernel too big! (size: %ld, max: %d)\n",
			       kernel_size, BZIMAGE_MAX_SIZE);
			return 0;
		}

	} else if ((kernel_size) > ZIMAGE_MAX_SIZE) {
		printf("Error: zImage kernel too big! (size: %ld, max: %d)\n",
		       kernel_size, ZIMAGE_MAX_SIZE);
		return 0;
	}

	/* build command line at COMMAND_LINE_OFFSET */
	build_command_line(setup_base + COMMAND_LINE_OFFSET, auto_boot);

	printf("Loading %czImage at address 0x%08x (%ld bytes)\n", big_image ? 'b' : ' ',
	       (u32)load_address, kernel_size);


	memmove(load_address, image + setup_size, kernel_size);

	/* ready for booting */
	return setup_base;
}

void boot_zimage(void *setup_base)
{
	struct pt_regs regs;

	memset(&regs, 0, sizeof(struct pt_regs));
	regs.xds = (u32)setup_base >> 4;
	regs.xes = regs.xds;
	regs.xss = regs.xds;
	regs.esp = 0x9000;
	regs.eflags = 0;
	enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, &regs, &regs);
}

int do_zboot (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	void *base_ptr;
	void *bzImage_addr = NULL;
	char *s;
	ulong bzImage_size = 0;

	disable_interrupts();

	/* Setup board for maximum PC/AT Compatibility */
	setup_pcat_compatibility();

	if (argc >= 2)
		/* argv[1] holds the address of the bzImage */
		s = argv[1];
	else
		s = getenv("fileaddr");

	if (s)
		bzImage_addr = (void *)simple_strtoul(s, NULL, 16);

	if (argc >= 3)
		/* argv[2] holds the size of the bzImage */
		bzImage_size = simple_strtoul(argv[2], NULL, 16);

	/* Lets look for*/
	base_ptr = load_zimage (bzImage_addr, bzImage_size, 0, 0, 0);

	if (NULL == base_ptr) {
		printf ("## Kernel loading failed ...\n");
	} else {
		printf ("## Transferring control to Linux (at address %08x) ...\n",
			(u32)base_ptr);

		/* we assume that the kernel is in place */
		printf("\nStarting kernel ...\n\n");

		boot_zimage(base_ptr);
		/* does not return */
	}

	return -1;
}

U_BOOT_CMD(
	zboot, 2, 0,	do_zboot,
	"Boot bzImage",
	""
);