xref: /openbmc/u-boot/arch/x86/lib/zimage.c (revision 29b103c7)
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 /*
46  * Install a default e820 table with 3 entries as follows:
47  *
48  *	0x000000-0x0a0000	Useable RAM
49  *	0x0a0000-0x100000	Reserved for ISA
50  *	0x100000-gd->ram_size	Useable RAM
51  */
52 __weak unsigned install_e820_map(unsigned max_entries,
53 				 struct e820entry *entries)
54 {
55 	entries[0].addr = 0;
56 	entries[0].size = ISA_START_ADDRESS;
57 	entries[0].type = E820_RAM;
58 	entries[1].addr = ISA_START_ADDRESS;
59 	entries[1].size = ISA_END_ADDRESS - ISA_START_ADDRESS;
60 	entries[1].type = E820_RESERVED;
61 	entries[2].addr = ISA_END_ADDRESS;
62 	entries[2].size = gd->ram_size - ISA_END_ADDRESS;
63 	entries[2].type = E820_RAM;
64 
65 	return 3;
66 }
67 
68 static void build_command_line(char *command_line, int auto_boot)
69 {
70 	char *env_command_line;
71 
72 	command_line[0] = '\0';
73 
74 	env_command_line =  getenv("bootargs");
75 
76 	/* set console= argument if we use a serial console */
77 	if (!strstr(env_command_line, "console=")) {
78 		if (!strcmp(getenv("stdout"), "serial")) {
79 
80 			/* We seem to use serial console */
81 			sprintf(command_line, "console=ttyS0,%s ",
82 				getenv("baudrate"));
83 		}
84 	}
85 
86 	if (auto_boot)
87 		strcat(command_line, "auto ");
88 
89 	if (env_command_line)
90 		strcat(command_line, env_command_line);
91 
92 	printf("Kernel command line: \"%s\"\n", command_line);
93 }
94 
95 static int kernel_magic_ok(struct setup_header *hdr)
96 {
97 	if (KERNEL_MAGIC != hdr->boot_flag) {
98 		printf("Error: Invalid Boot Flag "
99 			"(found 0x%04x, expected 0x%04x)\n",
100 			hdr->boot_flag, KERNEL_MAGIC);
101 		return 0;
102 	} else {
103 		printf("Valid Boot Flag\n");
104 		return 1;
105 	}
106 }
107 
108 static int get_boot_protocol(struct setup_header *hdr)
109 {
110 	if (hdr->header == KERNEL_V2_MAGIC) {
111 		printf("Magic signature found\n");
112 		return hdr->version;
113 	} else {
114 		/* Very old kernel */
115 		printf("Magic signature not found\n");
116 		return 0x0100;
117 	}
118 }
119 
120 struct boot_params *load_zimage(char *image, unsigned long kernel_size,
121 				ulong *load_addressp)
122 {
123 	struct boot_params *setup_base;
124 	int setup_size;
125 	int bootproto;
126 	int big_image;
127 
128 	struct boot_params *params = (struct boot_params *)image;
129 	struct setup_header *hdr = &params->hdr;
130 
131 	/* base address for real-mode segment */
132 	setup_base = (struct boot_params *)DEFAULT_SETUP_BASE;
133 
134 	if (!kernel_magic_ok(hdr))
135 		return 0;
136 
137 	/* determine size of setup */
138 	if (0 == hdr->setup_sects) {
139 		printf("Setup Sectors = 0 (defaulting to 4)\n");
140 		setup_size = 5 * 512;
141 	} else {
142 		setup_size = (hdr->setup_sects + 1) * 512;
143 	}
144 
145 	printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);
146 
147 	if (setup_size > SETUP_MAX_SIZE)
148 		printf("Error: Setup is too large (%d bytes)\n", setup_size);
149 
150 	/* determine boot protocol version */
151 	bootproto = get_boot_protocol(hdr);
152 
153 	printf("Using boot protocol version %x.%02x\n",
154 	       (bootproto & 0xff00) >> 8, bootproto & 0xff);
155 
156 	if (bootproto >= 0x0200) {
157 		if (hdr->setup_sects >= 15) {
158 			printf("Linux kernel version %s\n",
159 				(char *)params +
160 				hdr->kernel_version + 0x200);
161 		} else {
162 			printf("Setup Sectors < 15 - "
163 				"Cannot print kernel version.\n");
164 		}
165 	}
166 
167 	/* Determine image type */
168 	big_image = (bootproto >= 0x0200) &&
169 		    (hdr->loadflags & BIG_KERNEL_FLAG);
170 
171 	/* Determine load address */
172 	if (big_image)
173 		*load_addressp = BZIMAGE_LOAD_ADDR;
174 	else
175 		*load_addressp = ZIMAGE_LOAD_ADDR;
176 
177 	printf("Building boot_params at 0x%8.8lx\n", (ulong)setup_base);
178 	memset(setup_base, 0, sizeof(*setup_base));
179 	setup_base->hdr = params->hdr;
180 
181 	if (bootproto >= 0x0204)
182 		kernel_size = hdr->syssize * 16;
183 	else
184 		kernel_size -= setup_size;
185 
186 	if (bootproto == 0x0100) {
187 		/*
188 		 * A very old kernel MUST have its real-mode code
189 		 * loaded at 0x90000
190 		 */
191 		if ((u32)setup_base != 0x90000) {
192 			/* Copy the real-mode kernel */
193 			memmove((void *)0x90000, setup_base, setup_size);
194 
195 			/* Copy the command line */
196 			memmove((void *)0x99000,
197 				(u8 *)setup_base + COMMAND_LINE_OFFSET,
198 				COMMAND_LINE_SIZE);
199 
200 			 /* Relocated */
201 			setup_base = (struct boot_params *)0x90000;
202 		}
203 
204 		/* It is recommended to clear memory up to the 32K mark */
205 		memset((u8 *)0x90000 + setup_size, 0,
206 		       SETUP_MAX_SIZE - setup_size);
207 	}
208 
209 	if (big_image) {
210 		if (kernel_size > BZIMAGE_MAX_SIZE) {
211 			printf("Error: bzImage kernel too big! "
212 				"(size: %ld, max: %d)\n",
213 				kernel_size, BZIMAGE_MAX_SIZE);
214 			return 0;
215 		}
216 	} else if ((kernel_size) > ZIMAGE_MAX_SIZE) {
217 		printf("Error: zImage kernel too big! (size: %ld, max: %d)\n",
218 		       kernel_size, ZIMAGE_MAX_SIZE);
219 		return 0;
220 	}
221 
222 	printf("Loading %s at address %lx (%ld bytes)\n",
223 	       big_image ? "bzImage" : "zImage", *load_addressp, kernel_size);
224 
225 	memmove((void *)*load_addressp, image + setup_size, kernel_size);
226 
227 	return setup_base;
228 }
229 
230 int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
231 		 unsigned long initrd_addr, unsigned long initrd_size)
232 {
233 	struct setup_header *hdr = &setup_base->hdr;
234 	int bootproto = get_boot_protocol(hdr);
235 
236 	setup_base->e820_entries = install_e820_map(
237 		ARRAY_SIZE(setup_base->e820_map), setup_base->e820_map);
238 
239 	if (bootproto == 0x0100) {
240 		setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
241 		setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET;
242 	}
243 	if (bootproto >= 0x0200) {
244 		hdr->type_of_loader = 8;
245 
246 		if (initrd_addr) {
247 			printf("Initial RAM disk at linear address "
248 			       "0x%08lx, size %ld bytes\n",
249 			       initrd_addr, initrd_size);
250 
251 			hdr->ramdisk_image = initrd_addr;
252 			hdr->ramdisk_size = initrd_size;
253 		}
254 	}
255 
256 	if (bootproto >= 0x0201) {
257 		hdr->heap_end_ptr = HEAP_END_OFFSET;
258 		hdr->loadflags |= HEAP_FLAG;
259 	}
260 
261 	if (cmd_line) {
262 		if (bootproto >= 0x0202) {
263 			hdr->cmd_line_ptr = (uintptr_t)cmd_line;
264 		} else if (bootproto >= 0x0200) {
265 			setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
266 			setup_base->screen_info.cl_offset =
267 				(uintptr_t)cmd_line - (uintptr_t)setup_base;
268 
269 			hdr->setup_move_size = 0x9100;
270 		}
271 
272 		/* build command line at COMMAND_LINE_OFFSET */
273 		build_command_line(cmd_line, auto_boot);
274 	}
275 
276 	setup_video(&setup_base->screen_info);
277 
278 	return 0;
279 }
280 
281 void setup_pcat_compatibility(void)
282 	__attribute__((weak, alias("__setup_pcat_compatibility")));
283 
284 void __setup_pcat_compatibility(void)
285 {
286 }
287 
288 int do_zboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
289 {
290 	struct boot_params *base_ptr;
291 	void *bzImage_addr = NULL;
292 	ulong load_address;
293 	char *s;
294 	ulong bzImage_size = 0;
295 	ulong initrd_addr = 0;
296 	ulong initrd_size = 0;
297 
298 	disable_interrupts();
299 
300 	/* Setup board for maximum PC/AT Compatibility */
301 	setup_pcat_compatibility();
302 
303 	if (argc >= 2) {
304 		/* argv[1] holds the address of the bzImage */
305 		s = argv[1];
306 	} else {
307 		s = getenv("fileaddr");
308 	}
309 
310 	if (s)
311 		bzImage_addr = (void *)simple_strtoul(s, NULL, 16);
312 
313 	if (argc >= 3) {
314 		/* argv[2] holds the size of the bzImage */
315 		bzImage_size = simple_strtoul(argv[2], NULL, 16);
316 	}
317 
318 	if (argc >= 4)
319 		initrd_addr = simple_strtoul(argv[3], NULL, 16);
320 	if (argc >= 5)
321 		initrd_size = simple_strtoul(argv[4], NULL, 16);
322 
323 	/* Lets look for */
324 	base_ptr = load_zimage(bzImage_addr, bzImage_size, &load_address);
325 
326 	if (!base_ptr) {
327 		puts("## Kernel loading failed ...\n");
328 		return -1;
329 	}
330 	if (setup_zimage(base_ptr, (char *)base_ptr + COMMAND_LINE_OFFSET,
331 			0, initrd_addr, initrd_size)) {
332 		puts("Setting up boot parameters failed ...\n");
333 		return -1;
334 	}
335 
336 	/* we assume that the kernel is in place */
337 	return boot_linux_kernel((ulong)base_ptr, load_address, false);
338 }
339 
340 U_BOOT_CMD(
341 	zboot, 5, 0,	do_zboot,
342 	"Boot bzImage",
343 	"[addr] [size] [initrd addr] [initrd size]\n"
344 	"      addr -        The optional starting address of the bzimage.\n"
345 	"                    If not set it defaults to the environment\n"
346 	"                    variable \"fileaddr\".\n"
347 	"      size -        The optional size of the bzimage. Defaults to\n"
348 	"                    zero.\n"
349 	"      initrd addr - The address of the initrd image to use, if any.\n"
350 	"      initrd size - The size of the initrd image to use, if any.\n"
351 );
352