1 /* 2 * (C) Copyright 2002 3 * Daniel Engström, 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 x86 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 39 /* 40 * Memory lay-out: 41 * 42 * relative to setup_base (which is 0x90000 currently) 43 * 44 * 0x0000-0x7FFF Real mode kernel 45 * 0x8000-0x8FFF Stack and heap 46 * 0x9000-0x90FF Kernel command line 47 */ 48 #define DEFAULT_SETUP_BASE 0x90000 49 #define COMMAND_LINE_OFFSET 0x9000 50 #define HEAP_END_OFFSET 0x8e00 51 52 #define COMMAND_LINE_SIZE 2048 53 54 static void build_command_line(char *command_line, int auto_boot) 55 { 56 char *env_command_line; 57 58 command_line[0] = '\0'; 59 60 env_command_line = getenv("bootargs"); 61 62 /* set console= argument if we use a serial console */ 63 if (!strstr(env_command_line, "console=")) { 64 if (!strcmp(getenv("stdout"), "serial")) { 65 66 /* We seem to use serial console */ 67 sprintf(command_line, "console=ttyS0,%s ", 68 getenv("baudrate")); 69 } 70 } 71 72 if (auto_boot) 73 strcat(command_line, "auto "); 74 75 if (env_command_line) 76 strcat(command_line, env_command_line); 77 78 printf("Kernel command line: \"%s\"\n", command_line); 79 } 80 81 void *load_zimage(char *image, unsigned long kernel_size, 82 unsigned long initrd_addr, unsigned long initrd_size, 83 int auto_boot) 84 { 85 void *setup_base; 86 int setup_size; 87 int bootproto; 88 int big_image; 89 void *load_address; 90 struct setup_header *hdr; 91 92 hdr = (struct setup_header *)(image + SETUP_SECTS_OFF); 93 94 /* base address for real-mode segment */ 95 setup_base = (void *)DEFAULT_SETUP_BASE; 96 97 if (KERNEL_MAGIC != hdr->boot_flag) { 98 printf("Error: Invalid Boot Flag (found 0x%04x, expected 0x%04x)\n", 99 hdr->boot_flag, KERNEL_MAGIC); 100 return 0; 101 } else { 102 printf("Valid Boot Flag\n"); 103 } 104 105 /* determine boot protocol version */ 106 if (KERNEL_V2_MAGIC == hdr->header) { 107 printf("Magic signature found\n"); 108 109 bootproto = hdr->version; 110 } else { 111 /* Very old kernel */ 112 printf("Magic signature not found\n"); 113 bootproto = 0x0100; 114 } 115 116 /* determine size of setup */ 117 if (0 == hdr->setup_sects) { 118 printf("Setup Sectors = 0 (defaulting to 4)\n"); 119 setup_size = 5 * 512; 120 } else { 121 setup_size = (hdr->setup_sects + 1) * 512; 122 } 123 124 printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size); 125 126 if (setup_size > SETUP_MAX_SIZE) 127 printf("Error: Setup is too large (%d bytes)\n", setup_size); 128 129 /* Determine image type */ 130 big_image = (bootproto >= 0x0200) && 131 (hdr->loadflags & BIG_KERNEL_FLAG); 132 133 /* Determine load address */ 134 load_address = (void *)(big_image ? 135 BZIMAGE_LOAD_ADDR : 136 ZIMAGE_LOAD_ADDR); 137 138 /* load setup */ 139 printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n", 140 (ulong)setup_base, setup_size); 141 memmove(setup_base, image, setup_size); 142 143 printf("Using boot protocol version %x.%02x\n", 144 (bootproto & 0xff00) >> 8, bootproto & 0xff); 145 146 if (bootproto == 0x0100) { 147 *(u16 *)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC; 148 *(u16 *)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET; 149 150 /* 151 * A very old kernel MUST have its real-mode code 152 * loaded at 0x90000 153 */ 154 if ((u32)setup_base != 0x90000) { 155 /* Copy the real-mode kernel */ 156 memmove((void *)0x90000, setup_base, setup_size); 157 158 /* Copy the command line */ 159 memmove((void *)0x99000, 160 setup_base + COMMAND_LINE_OFFSET, 161 COMMAND_LINE_SIZE); 162 163 /* Relocated */ 164 setup_base = (void *)0x90000; 165 } 166 167 /* It is recommended to clear memory up to the 32K mark */ 168 memset((void *)0x90000 + setup_size, 0, 169 SETUP_MAX_SIZE-setup_size); 170 } 171 172 /* We are now setting up the real-mode version of the header */ 173 hdr = (struct setup_header *)(setup_base + SETUP_SECTS_OFF); 174 175 if (bootproto >= 0x0200) { 176 hdr->type_of_loader = 8; 177 178 if (hdr->setup_sects >= 15) 179 printf("Linux kernel version %s\n", 180 (char *)(setup_base + 181 (hdr->kernel_version + 0x200))); 182 else 183 printf("Setup Sectors < 15 - Cannot print kernel version.\n"); 184 185 if (initrd_addr) { 186 printf("Initial RAM disk at linear address 0x%08lx, size %ld bytes\n", 187 initrd_addr, initrd_size); 188 189 hdr->ramdisk_image = initrd_addr; 190 hdr->ramdisk_size = initrd_size; 191 } 192 } 193 194 if (bootproto >= 0x0201) { 195 hdr->heap_end_ptr = HEAP_END_OFFSET; 196 hdr->loadflags |= HEAP_FLAG; 197 } 198 199 if (bootproto >= 0x0202) { 200 hdr->cmd_line_ptr = (u32)setup_base + COMMAND_LINE_OFFSET; 201 } else if (bootproto >= 0x0200) { 202 203 *(u16 *)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC; 204 *(u16 *)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET; 205 206 hdr->setup_move_size = 0x9100; 207 } 208 209 if (bootproto >= 0x0204) 210 kernel_size = hdr->syssize * 16; 211 else 212 kernel_size -= setup_size; 213 214 215 if (big_image) { 216 if ((kernel_size) > BZIMAGE_MAX_SIZE) { 217 printf("Error: bzImage kernel too big! (size: %ld, max: %d)\n", 218 kernel_size, BZIMAGE_MAX_SIZE); 219 return 0; 220 } 221 222 } else if ((kernel_size) > ZIMAGE_MAX_SIZE) { 223 printf("Error: zImage kernel too big! (size: %ld, max: %d)\n", 224 kernel_size, ZIMAGE_MAX_SIZE); 225 return 0; 226 } 227 228 /* build command line at COMMAND_LINE_OFFSET */ 229 build_command_line(setup_base + COMMAND_LINE_OFFSET, auto_boot); 230 231 printf("Loading %czImage at address 0x%08x (%ld bytes)\n", 232 big_image ? 'b' : ' ', (u32)load_address, kernel_size); 233 234 235 memmove(load_address, image + setup_size, kernel_size); 236 237 /* ready for booting */ 238 return setup_base; 239 } 240 241 void boot_zimage(void *setup_base) 242 { 243 struct pt_regs regs; 244 245 memset(®s, 0, sizeof(struct pt_regs)); 246 regs.xds = (u32)setup_base >> 4; 247 regs.xes = regs.xds; 248 regs.xss = regs.xds; 249 regs.esp = 0x9000; 250 regs.eflags = 0; 251 enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, ®s, 252 ®s); 253 } 254 255 int do_zboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]) 256 { 257 void *base_ptr; 258 void *bzImage_addr = NULL; 259 char *s; 260 ulong bzImage_size = 0; 261 262 disable_interrupts(); 263 264 /* Setup board for maximum PC/AT Compatibility */ 265 setup_pcat_compatibility(); 266 267 if (argc >= 2) 268 /* argv[1] holds the address of the bzImage */ 269 s = argv[1]; 270 else 271 s = getenv("fileaddr"); 272 273 if (s) 274 bzImage_addr = (void *)simple_strtoul(s, NULL, 16); 275 276 if (argc >= 3) 277 /* argv[2] holds the size of the bzImage */ 278 bzImage_size = simple_strtoul(argv[2], NULL, 16); 279 280 /* Lets look for*/ 281 base_ptr = load_zimage(bzImage_addr, bzImage_size, 0, 0, 0); 282 283 if (!base_ptr) { 284 printf("## Kernel loading failed ...\n"); 285 } else { 286 printf("## Transferring control to Linux (at address %08x) ...\n", 287 (u32)base_ptr); 288 289 /* we assume that the kernel is in place */ 290 printf("\nStarting kernel ...\n\n"); 291 292 boot_zimage(base_ptr); 293 /* does not return */ 294 } 295 296 return -1; 297 } 298 299 U_BOOT_CMD( 300 zboot, 2, 0, do_zboot, 301 "Boot bzImage", 302 "" 303 ); 304