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 #ifdef CONFIG_SYS_COREBOOT 40 #include <asm/arch/timestamp.h> 41 #endif 42 #include <linux/compiler.h> 43 44 /* 45 * Memory lay-out: 46 * 47 * relative to setup_base (which is 0x90000 currently) 48 * 49 * 0x0000-0x7FFF Real mode kernel 50 * 0x8000-0x8FFF Stack and heap 51 * 0x9000-0x90FF Kernel command line 52 */ 53 #define DEFAULT_SETUP_BASE 0x90000 54 #define COMMAND_LINE_OFFSET 0x9000 55 #define HEAP_END_OFFSET 0x8e00 56 57 #define COMMAND_LINE_SIZE 2048 58 59 unsigned generic_install_e820_map(unsigned max_entries, 60 struct e820entry *entries) 61 { 62 return 0; 63 } 64 65 unsigned install_e820_map(unsigned max_entries, 66 struct e820entry *entries) 67 __attribute__((weak, alias("generic_install_e820_map"))); 68 69 static void build_command_line(char *command_line, int auto_boot) 70 { 71 char *env_command_line; 72 73 command_line[0] = '\0'; 74 75 env_command_line = getenv("bootargs"); 76 77 /* set console= argument if we use a serial console */ 78 if (!strstr(env_command_line, "console=")) { 79 if (!strcmp(getenv("stdout"), "serial")) { 80 81 /* We seem to use serial console */ 82 sprintf(command_line, "console=ttyS0,%s ", 83 getenv("baudrate")); 84 } 85 } 86 87 if (auto_boot) 88 strcat(command_line, "auto "); 89 90 if (env_command_line) 91 strcat(command_line, env_command_line); 92 93 printf("Kernel command line: \"%s\"\n", command_line); 94 } 95 96 static int kernel_magic_ok(struct setup_header *hdr) 97 { 98 if (KERNEL_MAGIC != hdr->boot_flag) { 99 printf("Error: Invalid Boot Flag " 100 "(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 return 1; 106 } 107 } 108 109 static int get_boot_protocol(struct setup_header *hdr) 110 { 111 if (hdr->header == KERNEL_V2_MAGIC) { 112 printf("Magic signature found\n"); 113 return hdr->version; 114 } else { 115 /* Very old kernel */ 116 printf("Magic signature not found\n"); 117 return 0x0100; 118 } 119 } 120 121 struct boot_params *load_zimage(char *image, unsigned long kernel_size, 122 void **load_address) 123 { 124 struct boot_params *setup_base; 125 int setup_size; 126 int bootproto; 127 int big_image; 128 129 struct boot_params *params = (struct boot_params *)image; 130 struct setup_header *hdr = ¶ms->hdr; 131 132 /* base address for real-mode segment */ 133 setup_base = (struct boot_params *)DEFAULT_SETUP_BASE; 134 135 if (!kernel_magic_ok(hdr)) 136 return 0; 137 138 /* determine size of setup */ 139 if (0 == hdr->setup_sects) { 140 printf("Setup Sectors = 0 (defaulting to 4)\n"); 141 setup_size = 5 * 512; 142 } else { 143 setup_size = (hdr->setup_sects + 1) * 512; 144 } 145 146 printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size); 147 148 if (setup_size > SETUP_MAX_SIZE) 149 printf("Error: Setup is too large (%d bytes)\n", setup_size); 150 151 /* determine boot protocol version */ 152 bootproto = get_boot_protocol(hdr); 153 154 printf("Using boot protocol version %x.%02x\n", 155 (bootproto & 0xff00) >> 8, bootproto & 0xff); 156 157 if (bootproto >= 0x0200) { 158 if (hdr->setup_sects >= 15) { 159 printf("Linux kernel version %s\n", 160 (char *)params + 161 hdr->kernel_version + 0x200); 162 } else { 163 printf("Setup Sectors < 15 - " 164 "Cannot print kernel version.\n"); 165 } 166 } 167 168 /* Determine image type */ 169 big_image = (bootproto >= 0x0200) && 170 (hdr->loadflags & BIG_KERNEL_FLAG); 171 172 /* Determine load address */ 173 if (big_image) 174 *load_address = (void *)BZIMAGE_LOAD_ADDR; 175 else 176 *load_address = (void *)ZIMAGE_LOAD_ADDR; 177 178 #if (defined CONFIG_ZBOOT_32 || defined CONFIG_X86_NO_REAL_MODE) 179 printf("Building boot_params at 0x%8.8lx\n", (ulong)setup_base); 180 memset(setup_base, 0, sizeof(*setup_base)); 181 setup_base->hdr = params->hdr; 182 #else 183 /* load setup */ 184 printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n", 185 (ulong)setup_base, setup_size); 186 memmove(setup_base, image, setup_size); 187 #endif 188 189 if (bootproto >= 0x0204) 190 kernel_size = hdr->syssize * 16; 191 else 192 kernel_size -= setup_size; 193 194 if (bootproto == 0x0100) { 195 /* 196 * A very old kernel MUST have its real-mode code 197 * loaded at 0x90000 198 */ 199 if ((u32)setup_base != 0x90000) { 200 /* Copy the real-mode kernel */ 201 memmove((void *)0x90000, setup_base, setup_size); 202 203 /* Copy the command line */ 204 memmove((void *)0x99000, 205 (u8 *)setup_base + COMMAND_LINE_OFFSET, 206 COMMAND_LINE_SIZE); 207 208 /* Relocated */ 209 setup_base = (struct boot_params *)0x90000; 210 } 211 212 /* It is recommended to clear memory up to the 32K mark */ 213 memset((u8 *)0x90000 + setup_size, 0, 214 SETUP_MAX_SIZE - setup_size); 215 } 216 217 if (big_image) { 218 if (kernel_size > BZIMAGE_MAX_SIZE) { 219 printf("Error: bzImage kernel too big! " 220 "(size: %ld, max: %d)\n", 221 kernel_size, BZIMAGE_MAX_SIZE); 222 return 0; 223 } 224 } else if ((kernel_size) > ZIMAGE_MAX_SIZE) { 225 printf("Error: zImage kernel too big! (size: %ld, max: %d)\n", 226 kernel_size, ZIMAGE_MAX_SIZE); 227 return 0; 228 } 229 230 printf("Loading %s at address %p (%ld bytes)\n", 231 big_image ? "bzImage" : "zImage", *load_address, kernel_size); 232 233 memmove(*load_address, image + setup_size, kernel_size); 234 235 return setup_base; 236 } 237 238 int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot, 239 unsigned long initrd_addr, unsigned long initrd_size) 240 { 241 struct setup_header *hdr = &setup_base->hdr; 242 int bootproto = get_boot_protocol(hdr); 243 244 #if (defined CONFIG_ZBOOT_32 || defined CONFIG_X86_NO_REAL_MODE) 245 setup_base->e820_entries = install_e820_map( 246 ARRAY_SIZE(setup_base->e820_map), setup_base->e820_map); 247 #endif 248 249 if (bootproto == 0x0100) { 250 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC; 251 setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET; 252 } 253 if (bootproto >= 0x0200) { 254 hdr->type_of_loader = 8; 255 256 if (initrd_addr) { 257 printf("Initial RAM disk at linear address " 258 "0x%08lx, size %ld bytes\n", 259 initrd_addr, initrd_size); 260 261 hdr->ramdisk_image = initrd_addr; 262 hdr->ramdisk_size = initrd_size; 263 } 264 } 265 266 if (bootproto >= 0x0201) { 267 hdr->heap_end_ptr = HEAP_END_OFFSET; 268 hdr->loadflags |= HEAP_FLAG; 269 } 270 271 if (bootproto >= 0x0202) { 272 hdr->cmd_line_ptr = (uintptr_t)cmd_line; 273 } else if (bootproto >= 0x0200) { 274 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC; 275 setup_base->screen_info.cl_offset = 276 (uintptr_t)cmd_line - (uintptr_t)setup_base; 277 278 hdr->setup_move_size = 0x9100; 279 } 280 281 /* build command line at COMMAND_LINE_OFFSET */ 282 build_command_line(cmd_line, auto_boot); 283 return 0; 284 } 285 286 /* 287 * Implement a weak default function for boards that optionally 288 * need to clean up the system before jumping to the kernel. 289 */ 290 __weak void board_final_cleanup(void) 291 { 292 } 293 294 void boot_zimage(void *setup_base, void *load_address) 295 { 296 board_final_cleanup(); 297 298 printf("\nStarting kernel ...\n\n"); 299 300 #ifdef CONFIG_SYS_COREBOOT 301 timestamp_add_now(TS_U_BOOT_START_KERNEL); 302 #endif 303 #if defined CONFIG_ZBOOT_32 304 /* 305 * Set %ebx, %ebp, and %edi to 0, %esi to point to the boot_params 306 * structure, and then jump to the kernel. We assume that %cs is 307 * 0x10, 4GB flat, and read/execute, and the data segments are 0x18, 308 * 4GB flat, and read/write. U-boot is setting them up that way for 309 * itself in arch/i386/cpu/cpu.c. 310 */ 311 __asm__ __volatile__ ( 312 "movl $0, %%ebp\n" 313 "cli\n" 314 "jmp *%[kernel_entry]\n" 315 :: [kernel_entry]"a"(load_address), 316 [boot_params] "S"(setup_base), 317 "b"(0), "D"(0) 318 : "%ebp" 319 ); 320 #else 321 struct pt_regs regs; 322 323 memset(®s, 0, sizeof(struct pt_regs)); 324 regs.xds = (u32)setup_base >> 4; 325 regs.xes = regs.xds; 326 regs.xss = regs.xds; 327 regs.esp = 0x9000; 328 regs.eflags = 0; 329 enter_realmode(((u32)setup_base + SETUP_START_OFFSET) >> 4, 0, 330 ®s, ®s); 331 #endif 332 } 333 334 void setup_pcat_compatibility(void) 335 __attribute__((weak, alias("__setup_pcat_compatibility"))); 336 337 void __setup_pcat_compatibility(void) 338 { 339 } 340 341 int do_zboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]) 342 { 343 struct boot_params *base_ptr; 344 void *bzImage_addr = NULL; 345 void *load_address; 346 char *s; 347 ulong bzImage_size = 0; 348 ulong initrd_addr = 0; 349 ulong initrd_size = 0; 350 351 disable_interrupts(); 352 353 /* Setup board for maximum PC/AT Compatibility */ 354 setup_pcat_compatibility(); 355 356 if (argc >= 2) { 357 /* argv[1] holds the address of the bzImage */ 358 s = argv[1]; 359 } else { 360 s = getenv("fileaddr"); 361 } 362 363 if (s) 364 bzImage_addr = (void *)simple_strtoul(s, NULL, 16); 365 366 if (argc >= 3) { 367 /* argv[2] holds the size of the bzImage */ 368 bzImage_size = simple_strtoul(argv[2], NULL, 16); 369 } 370 371 if (argc >= 4) 372 initrd_addr = simple_strtoul(argv[3], NULL, 16); 373 if (argc >= 5) 374 initrd_size = simple_strtoul(argv[4], NULL, 16); 375 376 /* Lets look for */ 377 base_ptr = load_zimage(bzImage_addr, bzImage_size, &load_address); 378 379 if (!base_ptr) { 380 printf("## Kernel loading failed ...\n"); 381 return -1; 382 } 383 if (setup_zimage(base_ptr, (char *)base_ptr + COMMAND_LINE_OFFSET, 384 0, initrd_addr, initrd_size)) { 385 printf("Setting up boot parameters failed ...\n"); 386 return -1; 387 } 388 389 printf("## Transferring control to Linux " 390 "(at address %08x) ...\n", 391 (u32)base_ptr); 392 393 /* we assume that the kernel is in place */ 394 boot_zimage(base_ptr, load_address); 395 /* does not return */ 396 397 return -1; 398 } 399 400 U_BOOT_CMD( 401 zboot, 5, 0, do_zboot, 402 "Boot bzImage", 403 "[addr] [size] [initrd addr] [initrd size]\n" 404 " addr - The optional starting address of the bzimage.\n" 405 " If not set it defaults to the environment\n" 406 " variable \"fileaddr\".\n" 407 " size - The optional size of the bzimage. Defaults to\n" 408 " zero.\n" 409 " initrd addr - The address of the initrd image to use, if any.\n" 410 " initrd size - The size of the initrd image to use, if any.\n" 411 ); 412