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/bootparam.h>
  22 #ifdef CONFIG_SYS_COREBOOT
  23 #include <asm/arch/timestamp.h>
  24 #endif
  25 #include <linux/compiler.h>
  26
  27 /*
  28  * Memory lay-out:
  29  *
  30  * relative to setup_base (which is 0x90000 currently)
  31  *
  32  *      0x0000-0x7FFF   Real mode kernel
  33  *      0x8000-0x8FFF   Stack and heap
  34  *      0x9000-0x90FF   Kernel command line
  35  */
  36 #define DEFAULT_SETUP_BASE      0x90000
  37 #define COMMAND_LINE_OFFSET     0x9000
  38 #define HEAP_END_OFFSET         0x8e00
  39
  40 #define COMMAND_LINE_SIZE       2048
  41
  42 unsigned generic_install_e820_map(unsigned max_entries,
  43                                   struct e820entry *entries)
  44 {
  45         return 0;
  46 }
  47
  48 unsigned install_e820_map(unsigned max_entries,
  49                           struct e820entry *entries)
  50         __attribute__((weak, alias("generic_install_e820_map")));
  51
  52 static void build_command_line(char *command_line, int auto_boot)
  53 {
  54         char *env_command_line;
  55
  56         command_line[0] = '\0';
  57
  58         env_command_line =  getenv("bootargs");
  59
  60         /* set console= argument if we use a serial console */
  61         if (!strstr(env_command_line, "console=")) {
  62                 if (!strcmp(getenv("stdout"), "serial")) {
  63
  64                         /* We seem to use serial console */
  65                         sprintf(command_line, "console=ttyS0,%s ",
  66                                 getenv("baudrate"));
  67                 }
  68         }
  69
  70         if (auto_boot)
  71                 strcat(command_line, "auto ");
  72
  73         if (env_command_line)
  74                 strcat(command_line, env_command_line);
  75
  76         printf("Kernel command line: \"%s\"\n", command_line);
  77 }
  78
  79 static int kernel_magic_ok(struct setup_header *hdr)
  80 {
  81         if (KERNEL_MAGIC != hdr->boot_flag) {
  82                 printf("Error: Invalid Boot Flag "
  83                         "(found 0x%04x, expected 0x%04x)\n",
  84                         hdr->boot_flag, KERNEL_MAGIC);
  85                 return 0;
  86         } else {
  87                 printf("Valid Boot Flag\n");
  88                 return 1;
  89         }
  90 }
  91
  92 static int get_boot_protocol(struct setup_header *hdr)
  93 {
  94         if (hdr->header == KERNEL_V2_MAGIC) {
  95                 printf("Magic signature found\n");
  96                 return hdr->version;
  97         } else {
  98                 /* Very old kernel */
  99                 printf("Magic signature not found\n");
 100                 return 0x0100;
 101         }
 102 }
 103
 104 struct boot_params *load_zimage(char *image, unsigned long kernel_size,
 105                                 void **load_address)
 106 {
 107         struct boot_params *setup_base;
 108         int setup_size;
 109         int bootproto;
 110         int big_image;
 111
 112         struct boot_params *params = (struct boot_params *)image;
 113         struct setup_header *hdr = &params->hdr;
 114
 115         /* base address for real-mode segment */
 116         setup_base = (struct boot_params *)DEFAULT_SETUP_BASE;
 117
 118         if (!kernel_magic_ok(hdr))
 119                 return 0;
 120
 121         /* determine size of setup */
 122         if (0 == hdr->setup_sects) {
 123                 printf("Setup Sectors = 0 (defaulting to 4)\n");
 124                 setup_size = 5 * 512;
 125         } else {
 126                 setup_size = (hdr->setup_sects + 1) * 512;
 127         }
 128
 129         printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);
 130
 131         if (setup_size > SETUP_MAX_SIZE)
 132                 printf("Error: Setup is too large (%d bytes)\n", setup_size);
 133
 134         /* determine boot protocol version */
 135         bootproto = get_boot_protocol(hdr);
 136
 137         printf("Using boot protocol version %x.%02x\n",
 138                (bootproto & 0xff00) >> 8, bootproto & 0xff);
 139
 140         if (bootproto >= 0x0200) {
 141                 if (hdr->setup_sects >= 15) {
 142                         printf("Linux kernel version %s\n",
 143                                 (char *)params +
 144                                 hdr->kernel_version + 0x200);
 145                 } else {
 146                         printf("Setup Sectors < 15 - "
 147                                 "Cannot print kernel version.\n");
 148                 }
 149         }
 150
 151         /* Determine image type */
 152         big_image = (bootproto >= 0x0200) &&
 153                     (hdr->loadflags & BIG_KERNEL_FLAG);
 154
 155         /* Determine load address */
 156         if (big_image)
 157                 *load_address = (void *)BZIMAGE_LOAD_ADDR;
 158         else
 159                 *load_address = (void *)ZIMAGE_LOAD_ADDR;
 160
 161         printf("Building boot_params at 0x%8.8lx\n", (ulong)setup_base);
 162         memset(setup_base, 0, sizeof(*setup_base));
 163         setup_base->hdr = params->hdr;
 164
 165         if (bootproto >= 0x0204)
 166                 kernel_size = hdr->syssize * 16;
 167         else
 168                 kernel_size -= setup_size;
 169
 170         if (bootproto == 0x0100) {
 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         if (big_image) {
 194                 if (kernel_size > BZIMAGE_MAX_SIZE) {
 195                         printf("Error: bzImage kernel too big! "
 196                                 "(size: %ld, max: %d)\n",
 197                                 kernel_size, BZIMAGE_MAX_SIZE);
 198                         return 0;
 199                 }
 200         } else if ((kernel_size) > ZIMAGE_MAX_SIZE) {
 201                 printf("Error: zImage kernel too big! (size: %ld, max: %d)\n",
 202                        kernel_size, ZIMAGE_MAX_SIZE);
 203                 return 0;
 204         }
 205
 206         printf("Loading %s at address %p (%ld bytes)\n",
 207                 big_image ? "bzImage" : "zImage", *load_address, kernel_size);
 208
 209         memmove(*load_address, image + setup_size, kernel_size);
 210
 211         return setup_base;
 212 }
 213
 214 int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
 215                  unsigned long initrd_addr, unsigned long initrd_size)
 216 {
 217         struct setup_header *hdr = &setup_base->hdr;
 218         int bootproto = get_boot_protocol(hdr);
 219
 220         setup_base->e820_entries = install_e820_map(
 221                 ARRAY_SIZE(setup_base->e820_map), setup_base->e820_map);
 222
 223         if (bootproto == 0x0100) {
 224                 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
 225                 setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET;
 226         }
 227         if (bootproto >= 0x0200) {
 228                 hdr->type_of_loader = 8;
 229
 230                 if (initrd_addr) {
 231                         printf("Initial RAM disk at linear address "
 232                                "0x%08lx, size %ld bytes\n",
 233                                initrd_addr, initrd_size);
 234
 235                         hdr->ramdisk_image = initrd_addr;
 236                         hdr->ramdisk_size = initrd_size;
 237                 }
 238         }
 239
 240         if (bootproto >= 0x0201) {
 241                 hdr->heap_end_ptr = HEAP_END_OFFSET;
 242                 hdr->loadflags |= HEAP_FLAG;
 243         }
 244
 245         if (bootproto >= 0x0202) {
 246                 hdr->cmd_line_ptr = (uintptr_t)cmd_line;
 247         } else if (bootproto >= 0x0200) {
 248                 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
 249                 setup_base->screen_info.cl_offset =
 250                         (uintptr_t)cmd_line - (uintptr_t)setup_base;
 251
 252                 hdr->setup_move_size = 0x9100;
 253         }
 254
 255         /* build command line at COMMAND_LINE_OFFSET */
 256         build_command_line(cmd_line, auto_boot);
 257         return 0;
 258 }
 259
 260 /*
 261  * Implement a weak default function for boards that optionally
 262  * need to clean up the system before jumping to the kernel.
 263  */
 264 __weak void board_final_cleanup(void)
 265 {
 266 }
 267
 268 void boot_zimage(void *setup_base, void *load_address)
 269 {
 270         debug("## Transferring control to Linux (at address %08x) ...\n",
 271               (u32)setup_base);
 272
 273         bootstage_mark_name(BOOTSTAGE_ID_BOOTM_HANDOFF, "start_kernel");
 274 #ifdef CONFIG_BOOTSTAGE_REPORT
 275         bootstage_report();
 276 #endif
 277         board_final_cleanup();
 278
 279         printf("\nStarting kernel ...\n\n");
 280
 281 #ifdef CONFIG_SYS_COREBOOT
 282         timestamp_add_now(TS_U_BOOT_START_KERNEL);
 283 #endif
 284         /*
 285          * Set %ebx, %ebp, and %edi to 0, %esi to point to the boot_params
 286          * structure, and then jump to the kernel. We assume that %cs is
 287          * 0x10, 4GB flat, and read/execute, and the data segments are 0x18,
 288          * 4GB flat, and read/write. U-boot is setting them up that way for
 289          * itself in arch/i386/cpu/cpu.c.
 290          */
 291         __asm__ __volatile__ (
 292         "movl $0, %%ebp\n"
 293         "cli\n"
 294         "jmp *%[kernel_entry]\n"
 295         :: [kernel_entry]"a"(load_address),
 296            [boot_params] "S"(setup_base),
 297            "b"(0), "D"(0)
 298         :  "%ebp"
 299         );
 300 }
 301
 302 void setup_pcat_compatibility(void)
 303         __attribute__((weak, alias("__setup_pcat_compatibility")));
 304
 305 void __setup_pcat_compatibility(void)
 306 {
 307 }
 308
 309 int do_zboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
 310 {
 311         struct boot_params *base_ptr;
 312         void *bzImage_addr = NULL;
 313         void *load_address;
 314         char *s;
 315         ulong bzImage_size = 0;
 316         ulong initrd_addr = 0;
 317         ulong initrd_size = 0;
 318
 319         disable_interrupts();
 320
 321         /* Setup board for maximum PC/AT Compatibility */
 322         setup_pcat_compatibility();
 323
 324         if (argc >= 2) {
 325                 /* argv[1] holds the address of the bzImage */
 326                 s = argv[1];
 327         } else {
 328                 s = getenv("fileaddr");
 329         }
 330
 331         if (s)
 332                 bzImage_addr = (void *)simple_strtoul(s, NULL, 16);
 333
 334         if (argc >= 3) {
 335                 /* argv[2] holds the size of the bzImage */
 336                 bzImage_size = simple_strtoul(argv[2], NULL, 16);
 337         }
 338
 339         if (argc >= 4)
 340                 initrd_addr = simple_strtoul(argv[3], NULL, 16);
 341         if (argc >= 5)
 342                 initrd_size = simple_strtoul(argv[4], NULL, 16);
 343
 344         /* Lets look for */
 345         base_ptr = load_zimage(bzImage_addr, bzImage_size, &load_address);
 346
 347         if (!base_ptr) {
 348                 printf("## Kernel loading failed ...\n");
 349                 return -1;
 350         }
 351         if (setup_zimage(base_ptr, (char *)base_ptr + COMMAND_LINE_OFFSET,
 352                         0, initrd_addr, initrd_size)) {
 353                 printf("Setting up boot parameters failed ...\n");
 354                 return -1;
 355         }
 356
 357         /* we assume that the kernel is in place */
 358         boot_zimage(base_ptr, load_address);
 359         /* does not return */
 360
 361         return -1;
 362 }
 363
 364 U_BOOT_CMD(
 365         zboot, 5, 0,    do_zboot,
 366         "Boot bzImage",
 367         "[addr] [size] [initrd addr] [initrd size]\n"
 368         "      addr -        The optional starting address of the bzimage.\n"
 369         "                    If not set it defaults to the environment\n"
 370         "                    variable \"fileaddr\".\n"
 371         "      size -        The optional size of the bzimage. Defaults to\n"
 372         "                    zero.\n"
 373         "      initrd addr - The address of the initrd image to use, if any.\n"
 374         "      initrd size - The size of the initrd image to use, if any.\n"
 375 );