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 = ¶ms->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 ); 376