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  * SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 /*
  10  * Linux x86 zImage and bzImage loading
  11  *
  12  * based on the procdure described in
  13  * linux/Documentation/i386/boot.txt
  14  */
  15
  16 #include <common.h>
  17 #include <asm/io.h>
  18 #include <asm/ptrace.h>
  19 #include <asm/zimage.h>
  20 #include <asm/byteorder.h>
  21 #include <asm/bootm.h>
  22 #include <asm/bootparam.h>
  23 #ifdef CONFIG_SYS_COREBOOT
  24 #include <asm/arch/timestamp.h>
  25 #endif
  26 #include <linux/compiler.h>
  27
  28 /*
  29  * Memory lay-out:
  30  *
  31  * relative to setup_base (which is 0x90000 currently)
  32  *
  33  *      0x0000-0x7FFF   Real mode kernel
  34  *      0x8000-0x8FFF   Stack and heap
  35  *      0x9000-0x90FF   Kernel command line
  36  */
  37 #define DEFAULT_SETUP_BASE      0x90000
  38 #define COMMAND_LINE_OFFSET     0x9000
  39 #define HEAP_END_OFFSET         0x8e00
  40
  41 #define COMMAND_LINE_SIZE       2048
  42
  43 unsigned generic_install_e820_map(unsigned max_entries,
  44                                   struct e820entry *entries)
  45 {
  46         return 0;
  47 }
  48
  49 unsigned install_e820_map(unsigned max_entries,
  50                           struct e820entry *entries)
  51         __attribute__((weak, alias("generic_install_e820_map")));
  52
  53 static void build_command_line(char *command_line, int auto_boot)
  54 {
  55         char *env_command_line;
  56
  57         command_line[0] = '\0';
  58
  59         env_command_line =  getenv("bootargs");
  60
  61         /* set console= argument if we use a serial console */
  62         if (!strstr(env_command_line, "console=")) {
  63                 if (!strcmp(getenv("stdout"), "serial")) {
  64
  65                         /* We seem to use serial console */
  66                         sprintf(command_line, "console=ttyS0,%s ",
  67                                 getenv("baudrate"));
  68                 }
  69         }
  70
  71         if (auto_boot)
  72                 strcat(command_line, "auto ");
  73
  74         if (env_command_line)
  75                 strcat(command_line, env_command_line);
  76
  77         printf("Kernel command line: \"%s\"\n", command_line);
  78 }
  79
  80 static int kernel_magic_ok(struct setup_header *hdr)
  81 {
  82         if (KERNEL_MAGIC != hdr->boot_flag) {
  83                 printf("Error: Invalid Boot Flag "
  84                         "(found 0x%04x, expected 0x%04x)\n",
  85                         hdr->boot_flag, KERNEL_MAGIC);
  86                 return 0;
  87         } else {
  88                 printf("Valid Boot Flag\n");
  89                 return 1;
  90         }
  91 }
  92
  93 static int get_boot_protocol(struct setup_header *hdr)
  94 {
  95         if (hdr->header == KERNEL_V2_MAGIC) {
  96                 printf("Magic signature found\n");
  97                 return hdr->version;
  98         } else {
  99                 /* Very old kernel */
 100                 printf("Magic signature not found\n");
 101                 return 0x0100;
 102         }
 103 }
 104
 105 struct boot_params *load_zimage(char *image, unsigned long kernel_size,
 106                                 void **load_address)
 107 {
 108         struct boot_params *setup_base;
 109         int setup_size;
 110         int bootproto;
 111         int big_image;
 112
 113         struct boot_params *params = (struct boot_params *)image;
 114         struct setup_header *hdr = &params->hdr;
 115
 116         /* base address for real-mode segment */
 117         setup_base = (struct boot_params *)DEFAULT_SETUP_BASE;
 118
 119         if (!kernel_magic_ok(hdr))
 120                 return 0;
 121
 122         /* determine size of setup */
 123         if (0 == hdr->setup_sects) {
 124                 printf("Setup Sectors = 0 (defaulting to 4)\n");
 125                 setup_size = 5 * 512;
 126         } else {
 127                 setup_size = (hdr->setup_sects + 1) * 512;
 128         }
 129
 130         printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);
 131
 132         if (setup_size > SETUP_MAX_SIZE)
 133                 printf("Error: Setup is too large (%d bytes)\n", setup_size);
 134
 135         /* determine boot protocol version */
 136         bootproto = get_boot_protocol(hdr);
 137
 138         printf("Using boot protocol version %x.%02x\n",
 139                (bootproto & 0xff00) >> 8, bootproto & 0xff);
 140
 141         if (bootproto >= 0x0200) {
 142                 if (hdr->setup_sects >= 15) {
 143                         printf("Linux kernel version %s\n",
 144                                 (char *)params +
 145                                 hdr->kernel_version + 0x200);
 146                 } else {
 147                         printf("Setup Sectors < 15 - "
 148                                 "Cannot print kernel version.\n");
 149                 }
 150         }
 151
 152         /* Determine image type */
 153         big_image = (bootproto >= 0x0200) &&
 154                     (hdr->loadflags & BIG_KERNEL_FLAG);
 155
 156         /* Determine load address */
 157         if (big_image)
 158                 *load_address = (void *)BZIMAGE_LOAD_ADDR;
 159         else
 160                 *load_address = (void *)ZIMAGE_LOAD_ADDR;
 161
 162         printf("Building boot_params at 0x%8.8lx\n", (ulong)setup_base);
 163         memset(setup_base, 0, sizeof(*setup_base));
 164         setup_base->hdr = params->hdr;
 165
 166         if (bootproto >= 0x0204)
 167                 kernel_size = hdr->syssize * 16;
 168         else
 169                 kernel_size -= setup_size;
 170
 171         if (bootproto == 0x0100) {
 172                 /*
 173                  * A very old kernel MUST have its real-mode code
 174                  * loaded at 0x90000
 175                  */
 176                 if ((u32)setup_base != 0x90000) {
 177                         /* Copy the real-mode kernel */
 178                         memmove((void *)0x90000, setup_base, setup_size);
 179
 180                         /* Copy the command line */
 181                         memmove((void *)0x99000,
 182                                 (u8 *)setup_base + COMMAND_LINE_OFFSET,
 183                                 COMMAND_LINE_SIZE);
 184
 185                          /* Relocated */
 186                         setup_base = (struct boot_params *)0x90000;
 187                 }
 188
 189                 /* It is recommended to clear memory up to the 32K mark */
 190                 memset((u8 *)0x90000 + setup_size, 0,
 191                        SETUP_MAX_SIZE - setup_size);
 192         }
 193
 194         if (big_image) {
 195                 if (kernel_size > BZIMAGE_MAX_SIZE) {
 196                         printf("Error: bzImage kernel too big! "
 197                                 "(size: %ld, max: %d)\n",
 198                                 kernel_size, BZIMAGE_MAX_SIZE);
 199                         return 0;
 200                 }
 201         } else if ((kernel_size) > ZIMAGE_MAX_SIZE) {
 202                 printf("Error: zImage kernel too big! (size: %ld, max: %d)\n",
 203                        kernel_size, ZIMAGE_MAX_SIZE);
 204                 return 0;
 205         }
 206
 207         printf("Loading %s at address %p (%ld bytes)\n",
 208                 big_image ? "bzImage" : "zImage", *load_address, kernel_size);
 209
 210         memmove(*load_address, image + setup_size, kernel_size);
 211
 212         return setup_base;
 213 }
 214
 215 int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
 216                  unsigned long initrd_addr, unsigned long initrd_size)
 217 {
 218         struct setup_header *hdr = &setup_base->hdr;
 219         int bootproto = get_boot_protocol(hdr);
 220
 221         setup_base->e820_entries = install_e820_map(
 222                 ARRAY_SIZE(setup_base->e820_map), setup_base->e820_map);
 223
 224         if (bootproto == 0x0100) {
 225                 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
 226                 setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET;
 227         }
 228         if (bootproto >= 0x0200) {
 229                 hdr->type_of_loader = 8;
 230
 231                 if (initrd_addr) {
 232                         printf("Initial RAM disk at linear address "
 233                                "0x%08lx, size %ld bytes\n",
 234                                initrd_addr, initrd_size);
 235
 236                         hdr->ramdisk_image = initrd_addr;
 237                         hdr->ramdisk_size = initrd_size;
 238                 }
 239         }
 240
 241         if (bootproto >= 0x0201) {
 242                 hdr->heap_end_ptr = HEAP_END_OFFSET;
 243                 hdr->loadflags |= HEAP_FLAG;
 244         }
 245
 246         if (cmd_line) {
 247                 if (bootproto >= 0x0202) {
 248                         hdr->cmd_line_ptr = (uintptr_t)cmd_line;
 249                 } else if (bootproto >= 0x0200) {
 250                         setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
 251                         setup_base->screen_info.cl_offset =
 252                                 (uintptr_t)cmd_line - (uintptr_t)setup_base;
 253
 254                         hdr->setup_move_size = 0x9100;
 255                 }
 256
 257                 /* build command line at COMMAND_LINE_OFFSET */
 258                 build_command_line(cmd_line, auto_boot);
 259         }
 260
 261         return 0;
 262 }
 263
 264 void boot_zimage(void *setup_base, void *load_address)
 265 {
 266         bootm_announce_and_cleanup();
 267
 268 #ifdef CONFIG_SYS_COREBOOT
 269         timestamp_add_now(TS_U_BOOT_START_KERNEL);
 270 #endif
 271         /*
 272          * Set %ebx, %ebp, and %edi to 0, %esi to point to the boot_params
 273          * structure, and then jump to the kernel. We assume that %cs is
 274          * 0x10, 4GB flat, and read/execute, and the data segments are 0x18,
 275          * 4GB flat, and read/write. U-boot is setting them up that way for
 276          * itself in arch/i386/cpu/cpu.c.
 277          */
 278         __asm__ __volatile__ (
 279         "movl $0, %%ebp\n"
 280         "cli\n"
 281         "jmp *%[kernel_entry]\n"
 282         :: [kernel_entry]"a"(load_address),
 283            [boot_params] "S"(setup_base),
 284            "b"(0), "D"(0)
 285         :  "%ebp"
 286         );
 287 }
 288
 289 void setup_pcat_compatibility(void)
 290         __attribute__((weak, alias("__setup_pcat_compatibility")));
 291
 292 void __setup_pcat_compatibility(void)
 293 {
 294 }
 295
 296 int do_zboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
 297 {
 298         struct boot_params *base_ptr;
 299         void *bzImage_addr = NULL;
 300         void *load_address;
 301         char *s;
 302         ulong bzImage_size = 0;
 303         ulong initrd_addr = 0;
 304         ulong initrd_size = 0;
 305
 306         disable_interrupts();
 307
 308         /* Setup board for maximum PC/AT Compatibility */
 309         setup_pcat_compatibility();
 310
 311         if (argc >= 2) {
 312                 /* argv[1] holds the address of the bzImage */
 313                 s = argv[1];
 314         } else {
 315                 s = getenv("fileaddr");
 316         }
 317
 318         if (s)
 319                 bzImage_addr = (void *)simple_strtoul(s, NULL, 16);
 320
 321         if (argc >= 3) {
 322                 /* argv[2] holds the size of the bzImage */
 323                 bzImage_size = simple_strtoul(argv[2], NULL, 16);
 324         }
 325
 326         if (argc >= 4)
 327                 initrd_addr = simple_strtoul(argv[3], NULL, 16);
 328         if (argc >= 5)
 329                 initrd_size = simple_strtoul(argv[4], NULL, 16);
 330
 331         /* Lets look for */
 332         base_ptr = load_zimage(bzImage_addr, bzImage_size, &load_address);
 333
 334         if (!base_ptr) {
 335                 printf("## Kernel loading failed ...\n");
 336                 return -1;
 337         }
 338         if (setup_zimage(base_ptr, (char *)base_ptr + COMMAND_LINE_OFFSET,
 339                         0, initrd_addr, initrd_size)) {
 340                 printf("Setting up boot parameters failed ...\n");
 341                 return -1;
 342         }
 343
 344         /* we assume that the kernel is in place */
 345         boot_zimage(base_ptr, load_address);
 346         /* does not return */
 347
 348         return -1;
 349 }
 350
 351 U_BOOT_CMD(
 352         zboot, 5, 0,    do_zboot,
 353         "Boot bzImage",
 354         "[addr] [size] [initrd addr] [initrd size]\n"
 355         "      addr -        The optional starting address of the bzimage.\n"
 356         "                    If not set it defaults to the environment\n"
 357         "                    variable \"fileaddr\".\n"
 358         "      size -        The optional size of the bzimage. Defaults to\n"
 359         "                    zero.\n"
 360         "      initrd addr - The address of the initrd image to use, if any.\n"
 361         "      initrd size - The size of the initrd image to use, if any.\n"
 362 );