xref: /openbmc/u-boot/arch/x86/lib/zimage.c (revision e9c847c3)
1 /*
2  * Copyright (c) 2011 The Chromium OS Authors.
3  * (C) Copyright 2002
4  * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
5  *
6  * SPDX-License-Identifier:	GPL-2.0+
7  */
8 
9 /*
10  * Linux x86 zImage and bzImage loading
11  *
12  * based on the procdure described in
13  * linux/Documentation/i386/boot.txt
14  */
15 
16 #include <common.h>
17 #include <asm/io.h>
18 #include <asm/ptrace.h>
19 #include <asm/zimage.h>
20 #include <asm/byteorder.h>
21 #include <asm/bootm.h>
22 #include <asm/bootparam.h>
23 #ifdef CONFIG_SYS_COREBOOT
24 #include <asm/arch/timestamp.h>
25 #endif
26 #include <linux/compiler.h>
27 
28 DECLARE_GLOBAL_DATA_PTR;
29 
30 /*
31  * Memory lay-out:
32  *
33  * relative to setup_base (which is 0x90000 currently)
34  *
35  *	0x0000-0x7FFF	Real mode kernel
36  *	0x8000-0x8FFF	Stack and heap
37  *	0x9000-0x90FF	Kernel command line
38  */
39 #define DEFAULT_SETUP_BASE	0x90000
40 #define COMMAND_LINE_OFFSET	0x9000
41 #define HEAP_END_OFFSET		0x8e00
42 
43 #define COMMAND_LINE_SIZE	2048
44 
45 static void build_command_line(char *command_line, int auto_boot)
46 {
47 	char *env_command_line;
48 
49 	command_line[0] = '\0';
50 
51 	env_command_line =  getenv("bootargs");
52 
53 	/* set console= argument if we use a serial console */
54 	if (!strstr(env_command_line, "console=")) {
55 		if (!strcmp(getenv("stdout"), "serial")) {
56 
57 			/* We seem to use serial console */
58 			sprintf(command_line, "console=ttyS0,%s ",
59 				getenv("baudrate"));
60 		}
61 	}
62 
63 	if (auto_boot)
64 		strcat(command_line, "auto ");
65 
66 	if (env_command_line)
67 		strcat(command_line, env_command_line);
68 
69 	printf("Kernel command line: \"%s\"\n", command_line);
70 }
71 
72 static int kernel_magic_ok(struct setup_header *hdr)
73 {
74 	if (KERNEL_MAGIC != hdr->boot_flag) {
75 		printf("Error: Invalid Boot Flag "
76 			"(found 0x%04x, expected 0x%04x)\n",
77 			hdr->boot_flag, KERNEL_MAGIC);
78 		return 0;
79 	} else {
80 		printf("Valid Boot Flag\n");
81 		return 1;
82 	}
83 }
84 
85 static int get_boot_protocol(struct setup_header *hdr)
86 {
87 	if (hdr->header == KERNEL_V2_MAGIC) {
88 		printf("Magic signature found\n");
89 		return hdr->version;
90 	} else {
91 		/* Very old kernel */
92 		printf("Magic signature not found\n");
93 		return 0x0100;
94 	}
95 }
96 
97 struct boot_params *load_zimage(char *image, unsigned long kernel_size,
98 				ulong *load_addressp)
99 {
100 	struct boot_params *setup_base;
101 	int setup_size;
102 	int bootproto;
103 	int big_image;
104 
105 	struct boot_params *params = (struct boot_params *)image;
106 	struct setup_header *hdr = &params->hdr;
107 
108 	/* base address for real-mode segment */
109 	setup_base = (struct boot_params *)DEFAULT_SETUP_BASE;
110 
111 	if (!kernel_magic_ok(hdr))
112 		return 0;
113 
114 	/* determine size of setup */
115 	if (0 == hdr->setup_sects) {
116 		printf("Setup Sectors = 0 (defaulting to 4)\n");
117 		setup_size = 5 * 512;
118 	} else {
119 		setup_size = (hdr->setup_sects + 1) * 512;
120 	}
121 
122 	printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);
123 
124 	if (setup_size > SETUP_MAX_SIZE)
125 		printf("Error: Setup is too large (%d bytes)\n", setup_size);
126 
127 	/* determine boot protocol version */
128 	bootproto = get_boot_protocol(hdr);
129 
130 	printf("Using boot protocol version %x.%02x\n",
131 	       (bootproto & 0xff00) >> 8, bootproto & 0xff);
132 
133 	if (bootproto >= 0x0200) {
134 		if (hdr->setup_sects >= 15) {
135 			printf("Linux kernel version %s\n",
136 				(char *)params +
137 				hdr->kernel_version + 0x200);
138 		} else {
139 			printf("Setup Sectors < 15 - "
140 				"Cannot print kernel version.\n");
141 		}
142 	}
143 
144 	/* Determine image type */
145 	big_image = (bootproto >= 0x0200) &&
146 		    (hdr->loadflags & BIG_KERNEL_FLAG);
147 
148 	/* Determine load address */
149 	if (big_image)
150 		*load_addressp = BZIMAGE_LOAD_ADDR;
151 	else
152 		*load_addressp = ZIMAGE_LOAD_ADDR;
153 
154 	printf("Building boot_params at 0x%8.8lx\n", (ulong)setup_base);
155 	memset(setup_base, 0, sizeof(*setup_base));
156 	setup_base->hdr = params->hdr;
157 
158 	if (bootproto >= 0x0204)
159 		kernel_size = hdr->syssize * 16;
160 	else
161 		kernel_size -= setup_size;
162 
163 	if (bootproto == 0x0100) {
164 		/*
165 		 * A very old kernel MUST have its real-mode code
166 		 * loaded at 0x90000
167 		 */
168 		if ((u32)setup_base != 0x90000) {
169 			/* Copy the real-mode kernel */
170 			memmove((void *)0x90000, setup_base, setup_size);
171 
172 			/* Copy the command line */
173 			memmove((void *)0x99000,
174 				(u8 *)setup_base + COMMAND_LINE_OFFSET,
175 				COMMAND_LINE_SIZE);
176 
177 			 /* Relocated */
178 			setup_base = (struct boot_params *)0x90000;
179 		}
180 
181 		/* It is recommended to clear memory up to the 32K mark */
182 		memset((u8 *)0x90000 + setup_size, 0,
183 		       SETUP_MAX_SIZE - setup_size);
184 	}
185 
186 	if (big_image) {
187 		if (kernel_size > BZIMAGE_MAX_SIZE) {
188 			printf("Error: bzImage kernel too big! "
189 				"(size: %ld, max: %d)\n",
190 				kernel_size, BZIMAGE_MAX_SIZE);
191 			return 0;
192 		}
193 	} else if ((kernel_size) > ZIMAGE_MAX_SIZE) {
194 		printf("Error: zImage kernel too big! (size: %ld, max: %d)\n",
195 		       kernel_size, ZIMAGE_MAX_SIZE);
196 		return 0;
197 	}
198 
199 	printf("Loading %s at address %lx (%ld bytes)\n",
200 	       big_image ? "bzImage" : "zImage", *load_addressp, kernel_size);
201 
202 	memmove((void *)*load_addressp, image + setup_size, kernel_size);
203 
204 	return setup_base;
205 }
206 
207 int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
208 		 unsigned long initrd_addr, unsigned long initrd_size)
209 {
210 	struct setup_header *hdr = &setup_base->hdr;
211 	int bootproto = get_boot_protocol(hdr);
212 
213 	setup_base->e820_entries = install_e820_map(
214 		ARRAY_SIZE(setup_base->e820_map), setup_base->e820_map);
215 
216 	if (bootproto == 0x0100) {
217 		setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
218 		setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET;
219 	}
220 	if (bootproto >= 0x0200) {
221 		hdr->type_of_loader = 8;
222 
223 		if (initrd_addr) {
224 			printf("Initial RAM disk at linear address "
225 			       "0x%08lx, size %ld bytes\n",
226 			       initrd_addr, initrd_size);
227 
228 			hdr->ramdisk_image = initrd_addr;
229 			hdr->ramdisk_size = initrd_size;
230 		}
231 	}
232 
233 	if (bootproto >= 0x0201) {
234 		hdr->heap_end_ptr = HEAP_END_OFFSET;
235 		hdr->loadflags |= HEAP_FLAG;
236 	}
237 
238 	if (cmd_line) {
239 		if (bootproto >= 0x0202) {
240 			hdr->cmd_line_ptr = (uintptr_t)cmd_line;
241 		} else if (bootproto >= 0x0200) {
242 			setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
243 			setup_base->screen_info.cl_offset =
244 				(uintptr_t)cmd_line - (uintptr_t)setup_base;
245 
246 			hdr->setup_move_size = 0x9100;
247 		}
248 
249 		/* build command line at COMMAND_LINE_OFFSET */
250 		build_command_line(cmd_line, auto_boot);
251 	}
252 
253 	setup_video(&setup_base->screen_info);
254 
255 	return 0;
256 }
257 
258 void setup_pcat_compatibility(void)
259 	__attribute__((weak, alias("__setup_pcat_compatibility")));
260 
261 void __setup_pcat_compatibility(void)
262 {
263 }
264 
265 int do_zboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
266 {
267 	struct boot_params *base_ptr;
268 	void *bzImage_addr = NULL;
269 	ulong load_address;
270 	char *s;
271 	ulong bzImage_size = 0;
272 	ulong initrd_addr = 0;
273 	ulong initrd_size = 0;
274 
275 	disable_interrupts();
276 
277 	/* Setup board for maximum PC/AT Compatibility */
278 	setup_pcat_compatibility();
279 
280 	if (argc >= 2) {
281 		/* argv[1] holds the address of the bzImage */
282 		s = argv[1];
283 	} else {
284 		s = getenv("fileaddr");
285 	}
286 
287 	if (s)
288 		bzImage_addr = (void *)simple_strtoul(s, NULL, 16);
289 
290 	if (argc >= 3) {
291 		/* argv[2] holds the size of the bzImage */
292 		bzImage_size = simple_strtoul(argv[2], NULL, 16);
293 	}
294 
295 	if (argc >= 4)
296 		initrd_addr = simple_strtoul(argv[3], NULL, 16);
297 	if (argc >= 5)
298 		initrd_size = simple_strtoul(argv[4], NULL, 16);
299 
300 	/* Lets look for */
301 	base_ptr = load_zimage(bzImage_addr, bzImage_size, &load_address);
302 
303 	if (!base_ptr) {
304 		puts("## Kernel loading failed ...\n");
305 		return -1;
306 	}
307 	if (setup_zimage(base_ptr, (char *)base_ptr + COMMAND_LINE_OFFSET,
308 			0, initrd_addr, initrd_size)) {
309 		puts("Setting up boot parameters failed ...\n");
310 		return -1;
311 	}
312 
313 	/* we assume that the kernel is in place */
314 	return boot_linux_kernel((ulong)base_ptr, load_address, false);
315 }
316 
317 U_BOOT_CMD(
318 	zboot, 5, 0,	do_zboot,
319 	"Boot bzImage",
320 	"[addr] [size] [initrd addr] [initrd size]\n"
321 	"      addr -        The optional starting address of the bzimage.\n"
322 	"                    If not set it defaults to the environment\n"
323 	"                    variable \"fileaddr\".\n"
324 	"      size -        The optional size of the bzimage. Defaults to\n"
325 	"                    zero.\n"
326 	"      initrd addr - The address of the initrd image to use, if any.\n"
327 	"      initrd size - The size of the initrd image to use, if any.\n"
328 );
329