xref: /openbmc/u-boot/arch/x86/lib/zimage.c (revision 5fecb36c)
1  /*
2   * Copyright (c) 2011 The Chromium OS Authors.
3   * (C) Copyright 2002
4   * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
5   *
6   * See file CREDITS for list of people who contributed to this
7   * project.
8   *
9   * This program is free software; you can redistribute it and/or
10   * modify it under the terms of the GNU General Public License as
11   * published by the Free Software Foundation; either version 2 of
12   * the License, or (at your option) any later version.
13   *
14   * This program is distributed in the hope that it will be useful,
15   * but WITHOUT ANY WARRANTY; without even the implied warranty of
16   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17   * GNU General Public License for more details.
18   *
19   * You should have received a copy of the GNU General Public License
20   * along with this program; if not, write to the Free Software
21   * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
22   * MA 02111-1307 USA
23   */
24  
25  /*
26   * Linux x86 zImage and bzImage loading
27   *
28   * based on the procdure described in
29   * linux/Documentation/i386/boot.txt
30   */
31  
32  #include <common.h>
33  #include <asm/io.h>
34  #include <asm/ptrace.h>
35  #include <asm/zimage.h>
36  #include <asm/realmode.h>
37  #include <asm/byteorder.h>
38  #include <asm/bootparam.h>
39  
40  /*
41   * Memory lay-out:
42   *
43   * relative to setup_base (which is 0x90000 currently)
44   *
45   *	0x0000-0x7FFF	Real mode kernel
46   *	0x8000-0x8FFF	Stack and heap
47   *	0x9000-0x90FF	Kernel command line
48   */
49  #define DEFAULT_SETUP_BASE	0x90000
50  #define COMMAND_LINE_OFFSET	0x9000
51  #define HEAP_END_OFFSET		0x8e00
52  
53  #define COMMAND_LINE_SIZE	2048
54  
55  unsigned generic_install_e820_map(unsigned max_entries,
56  				  struct e820entry *entries)
57  {
58  	return 0;
59  }
60  
61  unsigned install_e820_map(unsigned max_entries,
62  			  struct e820entry *entries)
63  	__attribute__((weak, alias("generic_install_e820_map")));
64  
65  static void build_command_line(char *command_line, int auto_boot)
66  {
67  	char *env_command_line;
68  
69  	command_line[0] = '\0';
70  
71  	env_command_line =  getenv("bootargs");
72  
73  	/* set console= argument if we use a serial console */
74  	if (!strstr(env_command_line, "console=")) {
75  		if (!strcmp(getenv("stdout"), "serial")) {
76  
77  			/* We seem to use serial console */
78  			sprintf(command_line, "console=ttyS0,%s ",
79  				getenv("baudrate"));
80  		}
81  	}
82  
83  	if (auto_boot)
84  		strcat(command_line, "auto ");
85  
86  	if (env_command_line)
87  		strcat(command_line, env_command_line);
88  
89  	printf("Kernel command line: \"%s\"\n", command_line);
90  }
91  
92  static int kernel_magic_ok(struct setup_header *hdr)
93  {
94  	if (KERNEL_MAGIC != hdr->boot_flag) {
95  		printf("Error: Invalid Boot Flag "
96  			"(found 0x%04x, expected 0x%04x)\n",
97  			hdr->boot_flag, KERNEL_MAGIC);
98  		return 0;
99  	} else {
100  		printf("Valid Boot Flag\n");
101  		return 1;
102  	}
103  }
104  
105  static int get_boot_protocol(struct setup_header *hdr)
106  {
107  	if (hdr->header == KERNEL_V2_MAGIC) {
108  		printf("Magic signature found\n");
109  		return hdr->version;
110  	} else {
111  		/* Very old kernel */
112  		printf("Magic signature not found\n");
113  		return 0x0100;
114  	}
115  }
116  
117  struct boot_params *load_zimage(char *image, unsigned long kernel_size,
118  				void **load_address)
119  {
120  	struct boot_params *setup_base;
121  	int setup_size;
122  	int bootproto;
123  	int big_image;
124  
125  	struct boot_params *params = (struct boot_params *)image;
126  	struct setup_header *hdr = &params->hdr;
127  
128  	/* base address for real-mode segment */
129  	setup_base = (struct boot_params *)DEFAULT_SETUP_BASE;
130  
131  	if (!kernel_magic_ok(hdr))
132  		return 0;
133  
134  	/* determine size of setup */
135  	if (0 == hdr->setup_sects) {
136  		printf("Setup Sectors = 0 (defaulting to 4)\n");
137  		setup_size = 5 * 512;
138  	} else {
139  		setup_size = (hdr->setup_sects + 1) * 512;
140  	}
141  
142  	printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);
143  
144  	if (setup_size > SETUP_MAX_SIZE)
145  		printf("Error: Setup is too large (%d bytes)\n", setup_size);
146  
147  	/* determine boot protocol version */
148  	bootproto = get_boot_protocol(hdr);
149  
150  	printf("Using boot protocol version %x.%02x\n",
151  	       (bootproto & 0xff00) >> 8, bootproto & 0xff);
152  
153  	if (bootproto >= 0x0200) {
154  		if (hdr->setup_sects >= 15) {
155  			printf("Linux kernel version %s\n",
156  				(char *)params +
157  				hdr->kernel_version + 0x200);
158  		} else {
159  			printf("Setup Sectors < 15 - "
160  				"Cannot print kernel version.\n");
161  		}
162  	}
163  
164  	/* Determine image type */
165  	big_image = (bootproto >= 0x0200) &&
166  		    (hdr->loadflags & BIG_KERNEL_FLAG);
167  
168  	/* Determine load address */
169  	if (big_image)
170  		*load_address = (void *)BZIMAGE_LOAD_ADDR;
171  	else
172  		*load_address = (void *)ZIMAGE_LOAD_ADDR;
173  
174  #if defined CONFIG_ZBOOT_32
175  	printf("Building boot_params at 0x%8.8lx\n", (ulong)setup_base);
176  	memset(setup_base, 0, sizeof(*setup_base));
177  	setup_base->hdr = params->hdr;
178  #else
179  	/* load setup */
180  	printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n",
181  	       (ulong)setup_base, setup_size);
182  	memmove(setup_base, image, setup_size);
183  #endif
184  
185  	if (bootproto >= 0x0204)
186  		kernel_size = hdr->syssize * 16;
187  	else
188  		kernel_size -= setup_size;
189  
190  	if (bootproto == 0x0100) {
191  		/*
192  		 * A very old kernel MUST have its real-mode code
193  		 * loaded at 0x90000
194  		 */
195  		if ((u32)setup_base != 0x90000) {
196  			/* Copy the real-mode kernel */
197  			memmove((void *)0x90000, setup_base, setup_size);
198  
199  			/* Copy the command line */
200  			memmove((void *)0x99000,
201  				(u8 *)setup_base + COMMAND_LINE_OFFSET,
202  				COMMAND_LINE_SIZE);
203  
204  			 /* Relocated */
205  			setup_base = (struct boot_params *)0x90000;
206  		}
207  
208  		/* It is recommended to clear memory up to the 32K mark */
209  		memset((u8 *)0x90000 + setup_size, 0,
210  		       SETUP_MAX_SIZE - setup_size);
211  	}
212  
213  	if (big_image) {
214  		if (kernel_size > BZIMAGE_MAX_SIZE) {
215  			printf("Error: bzImage kernel too big! "
216  				"(size: %ld, max: %d)\n",
217  				kernel_size, BZIMAGE_MAX_SIZE);
218  			return 0;
219  		}
220  	} else if ((kernel_size) > ZIMAGE_MAX_SIZE) {
221  		printf("Error: zImage kernel too big! (size: %ld, max: %d)\n",
222  		       kernel_size, ZIMAGE_MAX_SIZE);
223  		return 0;
224  	}
225  
226  	printf("Loading %s at address %p (%ld bytes)\n",
227  		big_image ? "bzImage" : "zImage", *load_address, kernel_size);
228  
229  	memmove(*load_address, image + setup_size, kernel_size);
230  
231  	return setup_base;
232  }
233  
234  int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
235  		 unsigned long initrd_addr, unsigned long initrd_size)
236  {
237  	struct setup_header *hdr = &setup_base->hdr;
238  	int bootproto = get_boot_protocol(hdr);
239  
240  #if defined CONFIG_ZBOOT_32
241  	setup_base->e820_entries = install_e820_map(
242  		ARRAY_SIZE(setup_base->e820_map), setup_base->e820_map);
243  #endif
244  
245  	if (bootproto == 0x0100) {
246  		setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
247  		setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET;
248  	}
249  	if (bootproto >= 0x0200) {
250  		hdr->type_of_loader = 8;
251  
252  		if (initrd_addr) {
253  			printf("Initial RAM disk at linear address "
254  			       "0x%08lx, size %ld bytes\n",
255  			       initrd_addr, initrd_size);
256  
257  			hdr->ramdisk_image = initrd_addr;
258  			hdr->ramdisk_size = initrd_size;
259  		}
260  	}
261  
262  	if (bootproto >= 0x0201) {
263  		hdr->heap_end_ptr = HEAP_END_OFFSET;
264  		hdr->loadflags |= HEAP_FLAG;
265  	}
266  
267  	if (bootproto >= 0x0202) {
268  		hdr->cmd_line_ptr = (uintptr_t)cmd_line;
269  	} else if (bootproto >= 0x0200) {
270  		setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
271  		setup_base->screen_info.cl_offset =
272  			(uintptr_t)cmd_line - (uintptr_t)setup_base;
273  
274  		hdr->setup_move_size = 0x9100;
275  	}
276  
277  	/* build command line at COMMAND_LINE_OFFSET */
278  	build_command_line(cmd_line, auto_boot);
279  	return 0;
280  }
281  
282  void boot_zimage(void *setup_base, void *load_address)
283  {
284  	printf("\nStarting kernel ...\n\n");
285  
286  #if defined CONFIG_ZBOOT_32
287  	/*
288  	 * Set %ebx, %ebp, and %edi to 0, %esi to point to the boot_params
289  	 * structure, and then jump to the kernel. We assume that %cs is
290  	 * 0x10, 4GB flat, and read/execute, and the data segments are 0x18,
291  	 * 4GB flat, and read/write. U-boot is setting them up that way for
292  	 * itself in arch/i386/cpu/cpu.c.
293  	 */
294  	__asm__ __volatile__ (
295  	"movl $0, %%ebp		\n"
296  	"cli			\n"
297  	"jmp %[kernel_entry]	\n"
298  	:: [kernel_entry]"a"(load_address),
299  	   [boot_params] "S"(setup_base),
300  	   "b"(0), "D"(0)
301  	:  "%ebp"
302  	);
303  #else
304  	struct pt_regs regs;
305  
306  	memset(&regs, 0, sizeof(struct pt_regs));
307  	regs.xds = (u32)setup_base >> 4;
308  	regs.xes = regs.xds;
309  	regs.xss = regs.xds;
310  	regs.esp = 0x9000;
311  	regs.eflags = 0;
312  	enter_realmode(((u32)setup_base + SETUP_START_OFFSET) >> 4, 0,
313  		       &regs, &regs);
314  #endif
315  }
316  
317  void setup_pcat_compatibility(void)
318  	__attribute__((weak, alias("__setup_pcat_compatibility")));
319  
320  void __setup_pcat_compatibility(void)
321  {
322  }
323  
324  int do_zboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
325  {
326  	struct boot_params *base_ptr;
327  	void *bzImage_addr = NULL;
328  	void *load_address;
329  	char *s;
330  	ulong bzImage_size = 0;
331  	ulong initrd_addr = 0;
332  	ulong initrd_size = 0;
333  
334  	disable_interrupts();
335  
336  	/* Setup board for maximum PC/AT Compatibility */
337  	setup_pcat_compatibility();
338  
339  	if (argc >= 2) {
340  		/* argv[1] holds the address of the bzImage */
341  		s = argv[1];
342  	} else {
343  		s = getenv("fileaddr");
344  	}
345  
346  	if (s)
347  		bzImage_addr = (void *)simple_strtoul(s, NULL, 16);
348  
349  	if (argc >= 3) {
350  		/* argv[2] holds the size of the bzImage */
351  		bzImage_size = simple_strtoul(argv[2], NULL, 16);
352  	}
353  
354  	if (argc >= 4)
355  		initrd_addr = simple_strtoul(argv[3], NULL, 16);
356  	if (argc >= 5)
357  		initrd_size = simple_strtoul(argv[4], NULL, 16);
358  
359  	/* Lets look for */
360  	base_ptr = load_zimage(bzImage_addr, bzImage_size, &load_address);
361  
362  	if (!base_ptr) {
363  		printf("## Kernel loading failed ...\n");
364  		return -1;
365  	}
366  	if (setup_zimage(base_ptr, (char *)base_ptr + COMMAND_LINE_OFFSET,
367  			0, initrd_addr, initrd_size)) {
368  		printf("Setting up boot parameters failed ...\n");
369  		return -1;
370  	}
371  
372  	printf("## Transferring control to Linux "
373  	       "(at address %08x) ...\n",
374  	       (u32)base_ptr);
375  
376  	/* we assume that the kernel is in place */
377  	boot_zimage(base_ptr, load_address);
378  	/* does not return */
379  
380  	return -1;
381  }
382  
383  U_BOOT_CMD(
384  	zboot, 5, 0,	do_zboot,
385  	"Boot bzImage",
386  	"[addr] [size] [initrd addr] [initrd size]\n"
387  	"      addr -        The optional starting address of the bzimage.\n"
388  	"                    If not set it defaults to the environment\n"
389  	"                    variable \"fileaddr\".\n"
390  	"      size -        The optional size of the bzimage. Defaults to\n"
391  	"                    zero.\n"
392  	"      initrd addr - The address of the initrd image to use, if any.\n"
393  	"      initrd size - The size of the initrd image to use, if any.\n"
394  );
395