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 43 /* 44 * Memory lay-out: 45 * 46 * relative to setup_base (which is 0x90000 currently) 47 * 48 * 0x0000-0x7FFF Real mode kernel 49 * 0x8000-0x8FFF Stack and heap 50 * 0x9000-0x90FF Kernel command line 51 */ 52 #define DEFAULT_SETUP_BASE 0x90000 53 #define COMMAND_LINE_OFFSET 0x9000 54 #define HEAP_END_OFFSET 0x8e00 55 56 #define COMMAND_LINE_SIZE 2048 57 58 unsigned generic_install_e820_map(unsigned max_entries, 59 struct e820entry *entries) 60 { 61 return 0; 62 } 63 64 unsigned install_e820_map(unsigned max_entries, 65 struct e820entry *entries) 66 __attribute__((weak, alias("generic_install_e820_map"))); 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 void **load_address) 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 = ¶ms->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_address = (void *)BZIMAGE_LOAD_ADDR; 174 else 175 *load_address = (void *)ZIMAGE_LOAD_ADDR; 176 177 #if (defined CONFIG_ZBOOT_32 || defined CONFIG_X86_NO_REAL_MODE) 178 printf("Building boot_params at 0x%8.8lx\n", (ulong)setup_base); 179 memset(setup_base, 0, sizeof(*setup_base)); 180 setup_base->hdr = params->hdr; 181 #else 182 /* load setup */ 183 printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n", 184 (ulong)setup_base, setup_size); 185 memmove(setup_base, image, setup_size); 186 #endif 187 188 if (bootproto >= 0x0204) 189 kernel_size = hdr->syssize * 16; 190 else 191 kernel_size -= setup_size; 192 193 if (bootproto == 0x0100) { 194 /* 195 * A very old kernel MUST have its real-mode code 196 * loaded at 0x90000 197 */ 198 if ((u32)setup_base != 0x90000) { 199 /* Copy the real-mode kernel */ 200 memmove((void *)0x90000, setup_base, setup_size); 201 202 /* Copy the command line */ 203 memmove((void *)0x99000, 204 (u8 *)setup_base + COMMAND_LINE_OFFSET, 205 COMMAND_LINE_SIZE); 206 207 /* Relocated */ 208 setup_base = (struct boot_params *)0x90000; 209 } 210 211 /* It is recommended to clear memory up to the 32K mark */ 212 memset((u8 *)0x90000 + setup_size, 0, 213 SETUP_MAX_SIZE - setup_size); 214 } 215 216 if (big_image) { 217 if (kernel_size > BZIMAGE_MAX_SIZE) { 218 printf("Error: bzImage kernel too big! " 219 "(size: %ld, max: %d)\n", 220 kernel_size, BZIMAGE_MAX_SIZE); 221 return 0; 222 } 223 } else if ((kernel_size) > ZIMAGE_MAX_SIZE) { 224 printf("Error: zImage kernel too big! (size: %ld, max: %d)\n", 225 kernel_size, ZIMAGE_MAX_SIZE); 226 return 0; 227 } 228 229 printf("Loading %s at address %p (%ld bytes)\n", 230 big_image ? "bzImage" : "zImage", *load_address, kernel_size); 231 232 memmove(*load_address, image + setup_size, kernel_size); 233 234 return setup_base; 235 } 236 237 int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot, 238 unsigned long initrd_addr, unsigned long initrd_size) 239 { 240 struct setup_header *hdr = &setup_base->hdr; 241 int bootproto = get_boot_protocol(hdr); 242 243 #if (defined CONFIG_ZBOOT_32 || defined CONFIG_X86_NO_REAL_MODE) 244 setup_base->e820_entries = install_e820_map( 245 ARRAY_SIZE(setup_base->e820_map), setup_base->e820_map); 246 #endif 247 248 if (bootproto == 0x0100) { 249 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC; 250 setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET; 251 } 252 if (bootproto >= 0x0200) { 253 hdr->type_of_loader = 8; 254 255 if (initrd_addr) { 256 printf("Initial RAM disk at linear address " 257 "0x%08lx, size %ld bytes\n", 258 initrd_addr, initrd_size); 259 260 hdr->ramdisk_image = initrd_addr; 261 hdr->ramdisk_size = initrd_size; 262 } 263 } 264 265 if (bootproto >= 0x0201) { 266 hdr->heap_end_ptr = HEAP_END_OFFSET; 267 hdr->loadflags |= HEAP_FLAG; 268 } 269 270 if (bootproto >= 0x0202) { 271 hdr->cmd_line_ptr = (uintptr_t)cmd_line; 272 } else if (bootproto >= 0x0200) { 273 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC; 274 setup_base->screen_info.cl_offset = 275 (uintptr_t)cmd_line - (uintptr_t)setup_base; 276 277 hdr->setup_move_size = 0x9100; 278 } 279 280 /* build command line at COMMAND_LINE_OFFSET */ 281 build_command_line(cmd_line, auto_boot); 282 return 0; 283 } 284 285 void boot_zimage(void *setup_base, void *load_address) 286 { 287 printf("\nStarting kernel ...\n\n"); 288 289 #ifdef CONFIG_SYS_COREBOOT 290 timestamp_add_now(TS_U_BOOT_START_KERNEL); 291 #endif 292 #if defined CONFIG_ZBOOT_32 293 /* 294 * Set %ebx, %ebp, and %edi to 0, %esi to point to the boot_params 295 * structure, and then jump to the kernel. We assume that %cs is 296 * 0x10, 4GB flat, and read/execute, and the data segments are 0x18, 297 * 4GB flat, and read/write. U-boot is setting them up that way for 298 * itself in arch/i386/cpu/cpu.c. 299 */ 300 __asm__ __volatile__ ( 301 "movl $0, %%ebp \n" 302 "cli \n" 303 "jmp %[kernel_entry] \n" 304 :: [kernel_entry]"a"(load_address), 305 [boot_params] "S"(setup_base), 306 "b"(0), "D"(0) 307 : "%ebp" 308 ); 309 #else 310 struct pt_regs regs; 311 312 memset(®s, 0, sizeof(struct pt_regs)); 313 regs.xds = (u32)setup_base >> 4; 314 regs.xes = regs.xds; 315 regs.xss = regs.xds; 316 regs.esp = 0x9000; 317 regs.eflags = 0; 318 enter_realmode(((u32)setup_base + SETUP_START_OFFSET) >> 4, 0, 319 ®s, ®s); 320 #endif 321 } 322 323 void setup_pcat_compatibility(void) 324 __attribute__((weak, alias("__setup_pcat_compatibility"))); 325 326 void __setup_pcat_compatibility(void) 327 { 328 } 329 330 int do_zboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]) 331 { 332 struct boot_params *base_ptr; 333 void *bzImage_addr = NULL; 334 void *load_address; 335 char *s; 336 ulong bzImage_size = 0; 337 ulong initrd_addr = 0; 338 ulong initrd_size = 0; 339 340 disable_interrupts(); 341 342 /* Setup board for maximum PC/AT Compatibility */ 343 setup_pcat_compatibility(); 344 345 if (argc >= 2) { 346 /* argv[1] holds the address of the bzImage */ 347 s = argv[1]; 348 } else { 349 s = getenv("fileaddr"); 350 } 351 352 if (s) 353 bzImage_addr = (void *)simple_strtoul(s, NULL, 16); 354 355 if (argc >= 3) { 356 /* argv[2] holds the size of the bzImage */ 357 bzImage_size = simple_strtoul(argv[2], NULL, 16); 358 } 359 360 if (argc >= 4) 361 initrd_addr = simple_strtoul(argv[3], NULL, 16); 362 if (argc >= 5) 363 initrd_size = simple_strtoul(argv[4], NULL, 16); 364 365 /* Lets look for */ 366 base_ptr = load_zimage(bzImage_addr, bzImage_size, &load_address); 367 368 if (!base_ptr) { 369 printf("## Kernel loading failed ...\n"); 370 return -1; 371 } 372 if (setup_zimage(base_ptr, (char *)base_ptr + COMMAND_LINE_OFFSET, 373 0, initrd_addr, initrd_size)) { 374 printf("Setting up boot parameters failed ...\n"); 375 return -1; 376 } 377 378 printf("## Transferring control to Linux " 379 "(at address %08x) ...\n", 380 (u32)base_ptr); 381 382 /* we assume that the kernel is in place */ 383 boot_zimage(base_ptr, load_address); 384 /* does not return */ 385 386 return -1; 387 } 388 389 U_BOOT_CMD( 390 zboot, 5, 0, do_zboot, 391 "Boot bzImage", 392 "[addr] [size] [initrd addr] [initrd size]\n" 393 " addr - The optional starting address of the bzimage.\n" 394 " If not set it defaults to the environment\n" 395 " variable \"fileaddr\".\n" 396 " size - The optional size of the bzimage. Defaults to\n" 397 " zero.\n" 398 " initrd addr - The address of the initrd image to use, if any.\n" 399 " initrd size - The size of the initrd image to use, if any.\n" 400 ); 401