1 /* 2 * (C) Copyright 2002 3 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se> 4 * 5 * See file CREDITS for list of people who contributed to this 6 * project. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation; either version 2 of 11 * the License, or (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21 * MA 02111-1307 USA 22 */ 23 24 /* 25 * Linux x86 zImage and bzImage loading 26 * 27 * based on the procdure described in 28 * linux/Documentation/i386/boot.txt 29 */ 30 31 #include <common.h> 32 #include <asm/io.h> 33 #include <asm/ptrace.h> 34 #include <asm/zimage.h> 35 #include <asm/realmode.h> 36 #include <asm/byteorder.h> 37 #include <asm/bootparam.h> 38 39 /* 40 * Memory lay-out: 41 * 42 * relative to setup_base (which is 0x90000 currently) 43 * 44 * 0x0000-0x7FFF Real mode kernel 45 * 0x8000-0x8FFF Stack and heap 46 * 0x9000-0x90FF Kernel command line 47 */ 48 #define DEFAULT_SETUP_BASE 0x90000 49 #define COMMAND_LINE_OFFSET 0x9000 50 #define HEAP_END_OFFSET 0x8e00 51 52 #define COMMAND_LINE_SIZE 2048 53 54 static void build_command_line(char *command_line, int auto_boot) 55 { 56 char *env_command_line; 57 58 command_line[0] = '\0'; 59 60 env_command_line = getenv("bootargs"); 61 62 /* set console= argument if we use a serial console */ 63 if (NULL == strstr(env_command_line, "console=")) { 64 if (0==strcmp(getenv("stdout"), "serial")) { 65 66 /* We seem to use serial console */ 67 sprintf(command_line, "console=ttyS0,%s ", 68 getenv("baudrate")); 69 } 70 } 71 72 if (auto_boot) { 73 strcat(command_line, "auto "); 74 } 75 76 if (NULL != env_command_line) { 77 strcat(command_line, env_command_line); 78 } 79 80 81 printf("Kernel command line: \"%s\"\n", command_line); 82 } 83 84 void *load_zimage(char *image, unsigned long kernel_size, 85 unsigned long initrd_addr, unsigned long initrd_size, 86 int auto_boot) 87 { 88 void *setup_base; 89 int setup_size; 90 int bootproto; 91 int big_image; 92 void *load_address; 93 94 struct setup_header *hdr = (struct setup_header *)(image + SETUP_SECTS_OFF); 95 96 setup_base = (void*)DEFAULT_SETUP_BASE; /* base address for real-mode segment */ 97 98 if (KERNEL_MAGIC != hdr->boot_flag) { 99 printf("Error: Invalid Boot Flag (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 } 105 106 /* determine boot protocol version */ 107 if (KERNEL_V2_MAGIC == hdr->header) { 108 printf("Magic signature found\n"); 109 110 bootproto = hdr->version; 111 } else { 112 /* Very old kernel */ 113 printf("Magic signature not found\n"); 114 bootproto = 0x0100; 115 } 116 117 /* determine size of setup */ 118 if (0 == hdr->setup_sects) { 119 printf("Setup Sectors = 0 (defaulting to 4)\n"); 120 setup_size = 5 * 512; 121 } else { 122 setup_size = (hdr->setup_sects + 1) * 512; 123 } 124 125 printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size); 126 127 if (setup_size > SETUP_MAX_SIZE) { 128 printf("Error: Setup is too large (%d bytes)\n", setup_size); 129 } 130 131 /* Determine image type */ 132 big_image = (bootproto >= 0x0200) && (hdr->loadflags & BIG_KERNEL_FLAG); 133 134 /* Determine load address */ 135 load_address = (void*)(big_image ? BZIMAGE_LOAD_ADDR : ZIMAGE_LOAD_ADDR); 136 137 /* load setup */ 138 printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n", (ulong)setup_base, setup_size); 139 memmove(setup_base, image, setup_size); 140 141 printf("Using boot protocol version %x.%02x\n", 142 (bootproto & 0xff00) >> 8, bootproto & 0xff); 143 144 if (bootproto == 0x0100) { 145 146 *(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC; 147 *(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET; 148 149 /* A very old kernel MUST have its real-mode code 150 * loaded at 0x90000 */ 151 152 if ((u32)setup_base != 0x90000) { 153 /* Copy the real-mode kernel */ 154 memmove((void*)0x90000, setup_base, setup_size); 155 /* Copy the command line */ 156 memmove((void*)0x99000, setup_base+COMMAND_LINE_OFFSET, 157 COMMAND_LINE_SIZE); 158 159 setup_base = (void*)0x90000; /* Relocated */ 160 } 161 162 /* It is recommended to clear memory up to the 32K mark */ 163 memset((void*)0x90000 + setup_size, 0, SETUP_MAX_SIZE-setup_size); 164 } 165 166 /* We are now setting up the real-mode version of the header */ 167 hdr = (struct setup_header *)(setup_base + SETUP_SECTS_OFF); 168 169 if (bootproto >= 0x0200) { 170 hdr->type_of_loader = 8; 171 172 if (hdr->setup_sects >= 15) 173 printf("Linux kernel version %s\n", (char *) 174 (setup_base + (hdr->kernel_version + 0x200))); 175 else 176 printf("Setup Sectors < 15 - Cannot print kernel version.\n"); 177 178 if (initrd_addr) { 179 printf("Initial RAM disk at linear address 0x%08lx, size %ld bytes\n", 180 initrd_addr, initrd_size); 181 182 hdr->ramdisk_image = initrd_addr; 183 hdr->ramdisk_size = initrd_size; 184 } 185 } 186 187 if (bootproto >= 0x0201) { 188 hdr->heap_end_ptr = HEAP_END_OFFSET; 189 hdr->loadflags |= HEAP_FLAG; 190 } 191 192 if (bootproto >= 0x0202) { 193 hdr->cmd_line_ptr = (u32)setup_base + COMMAND_LINE_OFFSET; 194 } else if (bootproto >= 0x0200) { 195 196 *(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC; 197 *(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET; 198 199 hdr->setup_move_size = 0x9100; 200 } 201 202 if (bootproto >= 0x0204) 203 kernel_size = hdr->syssize * 16; 204 else 205 kernel_size -= setup_size; 206 207 208 if (big_image) { 209 if ((kernel_size) > BZIMAGE_MAX_SIZE) { 210 printf("Error: bzImage kernel too big! (size: %ld, max: %d)\n", 211 kernel_size, BZIMAGE_MAX_SIZE); 212 return 0; 213 } 214 215 } else if ((kernel_size) > ZIMAGE_MAX_SIZE) { 216 printf("Error: zImage kernel too big! (size: %ld, max: %d)\n", 217 kernel_size, ZIMAGE_MAX_SIZE); 218 return 0; 219 } 220 221 /* build command line at COMMAND_LINE_OFFSET */ 222 build_command_line(setup_base + COMMAND_LINE_OFFSET, auto_boot); 223 224 printf("Loading %czImage at address 0x%08x (%ld bytes)\n", big_image ? 'b' : ' ', 225 (u32)load_address, kernel_size); 226 227 228 memmove(load_address, image + setup_size, kernel_size); 229 230 /* ready for booting */ 231 return setup_base; 232 } 233 234 void boot_zimage(void *setup_base) 235 { 236 struct pt_regs regs; 237 238 memset(®s, 0, sizeof(struct pt_regs)); 239 regs.xds = (u32)setup_base >> 4; 240 regs.xes = regs.xds; 241 regs.xss = regs.xds; 242 regs.esp = 0x9000; 243 regs.eflags = 0; 244 enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, ®s, ®s); 245 } 246 247 int do_zboot (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) 248 { 249 void *base_ptr; 250 void *bzImage_addr = NULL; 251 char *s; 252 ulong bzImage_size = 0; 253 254 disable_interrupts(); 255 256 /* Setup board for maximum PC/AT Compatibility */ 257 setup_pcat_compatibility(); 258 259 if (argc >= 2) 260 /* argv[1] holds the address of the bzImage */ 261 s = argv[1]; 262 else 263 s = getenv("fileaddr"); 264 265 if (s) 266 bzImage_addr = (void *)simple_strtoul(s, NULL, 16); 267 268 if (argc >= 3) 269 /* argv[2] holds the size of the bzImage */ 270 bzImage_size = simple_strtoul(argv[2], NULL, 16); 271 272 /* Lets look for*/ 273 base_ptr = load_zimage (bzImage_addr, bzImage_size, 0, 0, 0); 274 275 if (NULL == base_ptr) { 276 printf ("## Kernel loading failed ...\n"); 277 } else { 278 printf ("## Transferring control to Linux (at address %08x) ...\n", 279 (u32)base_ptr); 280 281 /* we assume that the kernel is in place */ 282 printf("\nStarting kernel ...\n\n"); 283 284 boot_zimage(base_ptr); 285 /* does not return */ 286 } 287 288 return -1; 289 } 290 291 U_BOOT_CMD( 292 zboot, 2, 0, do_zboot, 293 "Boot bzImage", 294 "" 295 ); 296