1 /*
2 * (C) Copyright 2002
3 * Daniel Engstr�m, Omicron Ceti AB, daniel@omicron.se
4 *
5 * See file CREDITS for list of people who contributed to this
6 * project.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21 * MA 02111-1307 USA
22 */
23
24 /*
25 * Linux i386 zImage and bzImage loading
26 *
27 * based on the procdure described in
28 * linux/Documentation/i386/boot.txt
29 */
30
31 #include <common.h>
32 #include <asm/io.h>
33 #include <asm/ptrace.h>
34 #include <asm/zimage.h>
35 #include <asm/realmode.h>
36 #include <asm/byteorder.h>
37 #include <asm/bootparam.h>
38 #include <asm/ic/sc520.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
build_command_line(char * command_line,int auto_boot)55 static void build_command_line(char *command_line, int auto_boot)
56 {
57 char *env_command_line;
58
59 command_line[0] = '\0';
60
61 env_command_line = getenv("bootargs");
62
63 /* set console= argument if we use a serial console */
64 if (NULL == strstr(env_command_line, "console=")) {
65 if (0==strcmp(getenv("stdout"), "serial")) {
66
67 /* We seem to use serial console */
68 sprintf(command_line, "console=ttyS0,%s ",
69 getenv("baudrate"));
70 }
71 }
72
73 if (auto_boot) {
74 strcat(command_line, "auto ");
75 }
76
77 if (NULL != env_command_line) {
78 strcat(command_line, env_command_line);
79 }
80
81
82 printf("Kernel command line: \"%s\"\n", command_line);
83 }
84
load_zimage(char * image,unsigned long kernel_size,unsigned long initrd_addr,unsigned long initrd_size,int auto_boot)85 void *load_zimage(char *image, unsigned long kernel_size,
86 unsigned long initrd_addr, unsigned long initrd_size,
87 int auto_boot)
88 {
89 void *setup_base;
90 int setup_size;
91 int bootproto;
92 int big_image;
93 void *load_address;
94
95 struct setup_header *hdr = (struct setup_header *)(image + SETUP_SECTS_OFF);
96
97 setup_base = (void*)DEFAULT_SETUP_BASE; /* base address for real-mode segment */
98
99 if (KERNEL_MAGIC != hdr->boot_flag) {
100 printf("Error: Invalid Boot Flag (found 0x%04x, expected 0x%04x)\n",
101 hdr->boot_flag, KERNEL_MAGIC);
102 return 0;
103 } else {
104 printf("Valid Boot Flag\n");
105 }
106
107 /* determine boot protocol version */
108 if (KERNEL_V2_MAGIC == hdr->header) {
109 printf("Magic signature found\n");
110
111 bootproto = hdr->version;
112 } else {
113 /* Very old kernel */
114 printf("Magic signature not found\n");
115 bootproto = 0x0100;
116 }
117
118 /* determine size of setup */
119 if (0 == hdr->setup_sects) {
120 printf("Setup Sectors = 0 (defaulting to 4)\n");
121 setup_size = 5 * 512;
122 } else {
123 setup_size = (hdr->setup_sects + 1) * 512;
124 }
125
126 printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);
127
128 if (setup_size > SETUP_MAX_SIZE) {
129 printf("Error: Setup is too large (%d bytes)\n", setup_size);
130 }
131
132 /* Determine image type */
133 big_image = (bootproto >= 0x0200) && (hdr->loadflags & BIG_KERNEL_FLAG);
134
135 /* Determine load address */
136 load_address = (void*)(big_image ? BZIMAGE_LOAD_ADDR : ZIMAGE_LOAD_ADDR);
137
138 /* load setup */
139 printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n", (ulong)setup_base, setup_size);
140 memmove(setup_base, image, setup_size);
141
142 printf("Using boot protocol version %x.%02x\n",
143 (bootproto & 0xff00) >> 8, bootproto & 0xff);
144
145 if (bootproto == 0x0100) {
146
147 *(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
148 *(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET;
149
150 /* A very old kernel MUST have its real-mode code
151 * loaded at 0x90000 */
152
153 if ((u32)setup_base != 0x90000) {
154 /* Copy the real-mode kernel */
155 memmove((void*)0x90000, setup_base, setup_size);
156 /* Copy the command line */
157 memmove((void*)0x99000, setup_base+COMMAND_LINE_OFFSET,
158 COMMAND_LINE_SIZE);
159
160 setup_base = (void*)0x90000; /* Relocated */
161 }
162
163 /* It is recommended to clear memory up to the 32K mark */
164 memset((void*)0x90000 + setup_size, 0, SETUP_MAX_SIZE-setup_size);
165 }
166
167 /* We are now setting up the real-mode version of the header */
168 hdr = (struct setup_header *)(setup_base + SETUP_SECTS_OFF);
169
170 if (bootproto >= 0x0200) {
171 hdr->type_of_loader = 8;
172
173 if (hdr->setup_sects >= 15)
174 printf("Linux kernel version %s\n", (char *)
175 (setup_base + (hdr->kernel_version + 0x200)));
176 else
177 printf("Setup Sectors < 15 - Cannot print kernel version.\n");
178
179 if (initrd_addr) {
180 printf("Initial RAM disk at linear address 0x%08lx, size %ld bytes\n",
181 initrd_addr, initrd_size);
182
183 hdr->ramdisk_image = initrd_addr;
184 hdr->ramdisk_size = initrd_size;
185 }
186 }
187
188 if (bootproto >= 0x0201) {
189 hdr->heap_end_ptr = HEAP_END_OFFSET;
190 hdr->loadflags |= HEAP_FLAG;
191 }
192
193 if (bootproto >= 0x0202) {
194 hdr->cmd_line_ptr = (u32)setup_base + COMMAND_LINE_OFFSET;
195 } else if (bootproto >= 0x0200) {
196
197 *(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
198 *(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET;
199
200 hdr->setup_move_size = 0x9100;
201 }
202
203 if (bootproto >= 0x0204)
204 kernel_size = hdr->syssize * 16;
205 else
206 kernel_size -= setup_size;
207
208
209 if (big_image) {
210 if ((kernel_size) > BZIMAGE_MAX_SIZE) {
211 printf("Error: bzImage kernel too big! (size: %ld, max: %d)\n",
212 kernel_size, BZIMAGE_MAX_SIZE);
213 return 0;
214 }
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 /* build command line at COMMAND_LINE_OFFSET */
223 build_command_line(setup_base + COMMAND_LINE_OFFSET, auto_boot);
224
225 printf("Loading %czImage at address 0x%08x (%ld bytes)\n", big_image ? 'b' : ' ',
226 (u32)load_address, kernel_size);
227
228
229 memmove(load_address, image + setup_size, kernel_size);
230
231 /* ready for booting */
232 return setup_base;
233 }
234
boot_zimage(void * setup_base)235 void boot_zimage(void *setup_base)
236 {
237 struct pt_regs regs;
238
239 memset(®s, 0, sizeof(struct pt_regs));
240 regs.xds = (u32)setup_base >> 4;
241 regs.xes = regs.xds;
242 regs.xss = regs.xds;
243 regs.esp = 0x9000;
244 regs.eflags = 0;
245 enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, ®s, ®s);
246 }
247
do_zboot(cmd_tbl_t * cmdtp,int flag,int argc,char * argv[])248 int do_zboot (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
249 {
250 void *base_ptr;
251 void *bzImage_addr;
252 ulong bzImage_size = 0;
253
254 disable_interrupts();
255
256 /* Setup board for maximum PC/AT Compatibility */
257 setup_pcat_compatibility();
258
259 /* argv[1] holds the address of the bzImage */
260 bzImage_addr = (void *)simple_strtoul(argv[1], NULL, 16);
261
262 if (argc == 3)
263 bzImage_size = simple_strtoul(argv[2], NULL, 16);
264
265 /* Lets look for*/
266 base_ptr = load_zimage (bzImage_addr, bzImage_size, 0, 0, 0);
267
268 if (NULL == base_ptr) {
269 printf ("## Kernel loading failed ...\n");
270 } else {
271 printf ("## Transferring control to Linux (at address %08x) ...\n",
272 (u32)base_ptr);
273
274 /* we assume that the kernel is in place */
275 printf("\nStarting kernel ...\n\n");
276
277 boot_zimage(base_ptr);
278 /* does not return */
279 }
280
281 return -1;
282 }
283
284 U_BOOT_CMD(
285 zboot, 3, 0, do_zboot,
286 "Boot bzImage",
287 ""
288 );
289