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