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 void *load_zimage(char *image, unsigned long kernel_size, 93 unsigned long initrd_addr, unsigned long initrd_size, 94 int auto_boot, void **load_address) 95 { 96 struct boot_params *setup_base; 97 int setup_size; 98 int bootproto; 99 int big_image; 100 101 struct boot_params *params = (struct boot_params *)image; 102 struct setup_header *hdr = ¶ms->hdr; 103 104 /* base address for real-mode segment */ 105 setup_base = (struct boot_params *)DEFAULT_SETUP_BASE; 106 107 if (KERNEL_MAGIC != hdr->boot_flag) { 108 printf("Error: Invalid Boot Flag " 109 "(found 0x%04x, expected 0x%04x)\n", 110 hdr->boot_flag, KERNEL_MAGIC); 111 return 0; 112 } else { 113 printf("Valid Boot Flag\n"); 114 } 115 116 /* determine boot protocol version */ 117 if (KERNEL_V2_MAGIC == hdr->header) { 118 printf("Magic signature found\n"); 119 120 bootproto = hdr->version; 121 } else { 122 /* Very old kernel */ 123 printf("Magic signature not found\n"); 124 bootproto = 0x0100; 125 } 126 127 /* determine size of setup */ 128 if (0 == hdr->setup_sects) { 129 printf("Setup Sectors = 0 (defaulting to 4)\n"); 130 setup_size = 5 * 512; 131 } else { 132 setup_size = (hdr->setup_sects + 1) * 512; 133 } 134 135 printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size); 136 137 if (setup_size > SETUP_MAX_SIZE) 138 printf("Error: Setup is too large (%d bytes)\n", setup_size); 139 140 /* Determine image type */ 141 big_image = (bootproto >= 0x0200) && 142 (hdr->loadflags & BIG_KERNEL_FLAG); 143 144 /* Determine load address */ 145 if (big_image) 146 *load_address = (void *)BZIMAGE_LOAD_ADDR; 147 else 148 *load_address = (void *)ZIMAGE_LOAD_ADDR; 149 150 #if defined CONFIG_ZBOOT_32 151 printf("Building boot_params at 0x%8.8lx\n", (ulong)setup_base); 152 memset(setup_base, 0, sizeof(*setup_base)); 153 setup_base->hdr = params->hdr; 154 155 setup_base->e820_entries = install_e820_map( 156 ARRAY_SIZE(setup_base->e820_map), setup_base->e820_map); 157 #else 158 /* load setup */ 159 printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n", 160 (ulong)setup_base, setup_size); 161 memmove(setup_base, image, setup_size); 162 #endif 163 164 printf("Using boot protocol version %x.%02x\n", 165 (bootproto & 0xff00) >> 8, bootproto & 0xff); 166 167 if (bootproto == 0x0100) { 168 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC; 169 setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET; 170 171 /* 172 * A very old kernel MUST have its real-mode code 173 * loaded at 0x90000 174 */ 175 if ((u32)setup_base != 0x90000) { 176 /* Copy the real-mode kernel */ 177 memmove((void *)0x90000, setup_base, setup_size); 178 179 /* Copy the command line */ 180 memmove((void *)0x99000, 181 (u8 *)setup_base + COMMAND_LINE_OFFSET, 182 COMMAND_LINE_SIZE); 183 184 /* Relocated */ 185 setup_base = (struct boot_params *)0x90000; 186 } 187 188 /* It is recommended to clear memory up to the 32K mark */ 189 memset((u8 *)0x90000 + setup_size, 0, 190 SETUP_MAX_SIZE - setup_size); 191 } 192 193 /* We are now setting up the real-mode version of the header */ 194 hdr = &setup_base->hdr; 195 196 if (bootproto >= 0x0200) { 197 hdr->type_of_loader = 8; 198 199 if (hdr->setup_sects >= 15) { 200 printf("Linux kernel version %s\n", 201 (char *)params + 202 hdr->kernel_version + 0x200); 203 } else { 204 printf("Setup Sectors < 15 - " 205 "Cannot print kernel version.\n"); 206 } 207 208 if (initrd_addr) { 209 printf("Initial RAM disk at linear address " 210 "0x%08lx, size %ld bytes\n", 211 initrd_addr, initrd_size); 212 213 hdr->ramdisk_image = initrd_addr; 214 hdr->ramdisk_size = initrd_size; 215 } 216 } 217 218 if (bootproto >= 0x0201) { 219 hdr->heap_end_ptr = HEAP_END_OFFSET; 220 hdr->loadflags |= HEAP_FLAG; 221 } 222 223 if (bootproto >= 0x0202) { 224 hdr->cmd_line_ptr = 225 (uintptr_t)setup_base + COMMAND_LINE_OFFSET; 226 } else if (bootproto >= 0x0200) { 227 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC; 228 setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET; 229 230 hdr->setup_move_size = 0x9100; 231 } 232 233 if (bootproto >= 0x0204) 234 kernel_size = hdr->syssize * 16; 235 else 236 kernel_size -= setup_size; 237 238 239 if (big_image) { 240 if ((kernel_size) > BZIMAGE_MAX_SIZE) { 241 printf("Error: bzImage kernel too big! " 242 "(size: %ld, max: %d)\n", 243 kernel_size, BZIMAGE_MAX_SIZE); 244 return 0; 245 } 246 } else if ((kernel_size) > ZIMAGE_MAX_SIZE) { 247 printf("Error: zImage kernel too big! (size: %ld, max: %d)\n", 248 kernel_size, ZIMAGE_MAX_SIZE); 249 return 0; 250 } 251 252 /* build command line at COMMAND_LINE_OFFSET */ 253 build_command_line((char *)setup_base + COMMAND_LINE_OFFSET, auto_boot); 254 255 printf("Loading %czImage at address 0x%08x (%ld bytes)\n", 256 big_image ? 'b' : ' ', (u32)*load_address, kernel_size); 257 258 memmove(*load_address, image + setup_size, kernel_size); 259 260 /* ready for booting */ 261 return setup_base; 262 } 263 264 void boot_zimage(void *setup_base, void *load_address) 265 { 266 printf("\nStarting kernel ...\n\n"); 267 268 #if defined CONFIG_ZBOOT_32 269 /* 270 * Set %ebx, %ebp, and %edi to 0, %esi to point to the boot_params 271 * structure, and then jump to the kernel. We assume that %cs is 272 * 0x10, 4GB flat, and read/execute, and the data segments are 0x18, 273 * 4GB flat, and read/write. U-boot is setting them up that way for 274 * itself in arch/i386/cpu/cpu.c. 275 */ 276 __asm__ __volatile__ ( 277 "movl $0, %%ebp \n" 278 "cli \n" 279 "jmp %[kernel_entry] \n" 280 :: [kernel_entry]"a"(load_address), 281 [boot_params] "S"(setup_base), 282 "b"(0), "D"(0) 283 : "%ebp" 284 ); 285 #else 286 struct pt_regs regs; 287 288 memset(®s, 0, sizeof(struct pt_regs)); 289 regs.xds = (u32)setup_base >> 4; 290 regs.xes = regs.xds; 291 regs.xss = regs.xds; 292 regs.esp = 0x9000; 293 regs.eflags = 0; 294 enter_realmode(((u32)setup_base + SETUP_START_OFFSET) >> 4, 0, 295 ®s, ®s); 296 #endif 297 } 298 299 int do_zboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]) 300 { 301 void *base_ptr; 302 void *bzImage_addr = NULL; 303 void *load_address; 304 char *s; 305 ulong bzImage_size = 0; 306 307 disable_interrupts(); 308 309 /* Setup board for maximum PC/AT Compatibility */ 310 setup_pcat_compatibility(); 311 312 if (argc >= 2) { 313 /* argv[1] holds the address of the bzImage */ 314 s = argv[1]; 315 } else { 316 s = getenv("fileaddr"); 317 } 318 319 if (s) 320 bzImage_addr = (void *)simple_strtoul(s, NULL, 16); 321 322 if (argc >= 3) 323 /* argv[2] holds the size of the bzImage */ 324 bzImage_size = simple_strtoul(argv[2], NULL, 16); 325 326 /* Lets look for */ 327 base_ptr = load_zimage(bzImage_addr, bzImage_size, 0, 0, 0, 328 &load_address); 329 330 if (!base_ptr) { 331 printf("## Kernel loading failed ...\n"); 332 } else { 333 printf("## Transferring control to Linux " 334 "(at address %08x) ...\n", 335 (u32)base_ptr); 336 337 /* we assume that the kernel is in place */ 338 boot_zimage(base_ptr, load_address); 339 /* does not return */ 340 } 341 342 return -1; 343 } 344 345 U_BOOT_CMD( 346 zboot, 2, 0, do_zboot, 347 "Boot bzImage", 348 "" 349 ); 350