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 = ¶ms->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(®s, 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 ®s, ®s); 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