arch/x86/lib/zimage.c

   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 = &params->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(&regs, 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                        &regs, &regs);
 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 );