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 #include <asm/ic/sc520.h> 39 40 /* 41 * Memory lay-out: 42 * 43 * relative to setup_base (which is 0x90000 currently) 44 * 45 * 0x0000-0x7FFF Real mode kernel 46 * 0x8000-0x8FFF Stack and heap 47 * 0x9000-0x90FF Kernel command line 48 */ 49 #define DEFAULT_SETUP_BASE 0x90000 50 #define COMMAND_LINE_OFFSET 0x9000 51 #define HEAP_END_OFFSET 0x8e00 52 53 #define COMMAND_LINE_SIZE 2048 54 55 static void build_command_line(char *command_line, int auto_boot) 56 { 57 char *env_command_line; 58 59 command_line[0] = '\0'; 60 61 env_command_line = getenv("bootargs"); 62 63 /* set console= argument if we use a serial console */ 64 if (NULL == strstr(env_command_line, "console=")) { 65 if (0==strcmp(getenv("stdout"), "serial")) { 66 67 /* We seem to use serial console */ 68 sprintf(command_line, "console=ttyS0,%s ", 69 getenv("baudrate")); 70 } 71 } 72 73 if (auto_boot) { 74 strcat(command_line, "auto "); 75 } 76 77 if (NULL != env_command_line) { 78 strcat(command_line, env_command_line); 79 } 80 81 82 printf("Kernel command line: \"%s\"\n", command_line); 83 } 84 85 void *load_zimage(char *image, unsigned long kernel_size, 86 unsigned long initrd_addr, unsigned long initrd_size, 87 int auto_boot) 88 { 89 void *setup_base; 90 int setup_size; 91 int bootproto; 92 int big_image; 93 void *load_address; 94 95 struct setup_header *hdr = (struct setup_header *)(image + SETUP_SECTS_OFF); 96 97 setup_base = (void*)DEFAULT_SETUP_BASE; /* base address for real-mode segment */ 98 99 if (KERNEL_MAGIC != hdr->boot_flag) { 100 printf("Error: Invalid Boot Flag (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 } 106 107 /* determine boot protocol version */ 108 if (KERNEL_V2_MAGIC == hdr->header) { 109 printf("Magic signature found\n"); 110 111 bootproto = hdr->version; 112 } else { 113 /* Very old kernel */ 114 printf("Magic signature not found\n"); 115 bootproto = 0x0100; 116 } 117 118 /* determine size of setup */ 119 if (0 == hdr->setup_sects) { 120 printf("Setup Sectors = 0 (defaulting to 4)\n"); 121 setup_size = 5 * 512; 122 } else { 123 setup_size = (hdr->setup_sects + 1) * 512; 124 } 125 126 printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size); 127 128 if (setup_size > SETUP_MAX_SIZE) { 129 printf("Error: Setup is too large (%d bytes)\n", setup_size); 130 } 131 132 /* Determine image type */ 133 big_image = (bootproto >= 0x0200) && (hdr->loadflags & BIG_KERNEL_FLAG); 134 135 /* Determine load address */ 136 load_address = (void*)(big_image ? BZIMAGE_LOAD_ADDR : ZIMAGE_LOAD_ADDR); 137 138 /* load setup */ 139 printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n", (ulong)setup_base, setup_size); 140 memmove(setup_base, image, setup_size); 141 142 printf("Using boot protocol version %x.%02x\n", 143 (bootproto & 0xff00) >> 8, bootproto & 0xff); 144 145 if (bootproto == 0x0100) { 146 147 *(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC; 148 *(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET; 149 150 /* A very old kernel MUST have its real-mode code 151 * loaded at 0x90000 */ 152 153 if ((u32)setup_base != 0x90000) { 154 /* Copy the real-mode kernel */ 155 memmove((void*)0x90000, setup_base, setup_size); 156 /* Copy the command line */ 157 memmove((void*)0x99000, setup_base+COMMAND_LINE_OFFSET, 158 COMMAND_LINE_SIZE); 159 160 setup_base = (void*)0x90000; /* Relocated */ 161 } 162 163 /* It is recommended to clear memory up to the 32K mark */ 164 memset((void*)0x90000 + setup_size, 0, SETUP_MAX_SIZE-setup_size); 165 } 166 167 /* We are now setting up the real-mode version of the header */ 168 hdr = (struct setup_header *)(setup_base + SETUP_SECTS_OFF); 169 170 if (bootproto >= 0x0200) { 171 hdr->type_of_loader = 8; 172 173 if (hdr->setup_sects >= 15) 174 printf("Linux kernel version %s\n", (char *) 175 (setup_base + (hdr->kernel_version + 0x200))); 176 else 177 printf("Setup Sectors < 15 - Cannot print kernel version.\n"); 178 179 if (initrd_addr) { 180 printf("Initial RAM disk at linear address 0x%08lx, size %ld bytes\n", 181 initrd_addr, initrd_size); 182 183 hdr->ramdisk_image = initrd_addr; 184 hdr->ramdisk_size = initrd_size; 185 } 186 } 187 188 if (bootproto >= 0x0201) { 189 hdr->heap_end_ptr = HEAP_END_OFFSET; 190 hdr->loadflags |= HEAP_FLAG; 191 } 192 193 if (bootproto >= 0x0202) { 194 hdr->cmd_line_ptr = (u32)setup_base + COMMAND_LINE_OFFSET; 195 } else if (bootproto >= 0x0200) { 196 197 *(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC; 198 *(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET; 199 200 hdr->setup_move_size = 0x9100; 201 } 202 203 if (bootproto >= 0x0204) 204 kernel_size = hdr->syssize * 16; 205 else 206 kernel_size -= setup_size; 207 208 209 if (big_image) { 210 if ((kernel_size) > BZIMAGE_MAX_SIZE) { 211 printf("Error: bzImage kernel too big! (size: %ld, max: %d)\n", 212 kernel_size, BZIMAGE_MAX_SIZE); 213 return 0; 214 } 215 216 } else if ((kernel_size) > ZIMAGE_MAX_SIZE) { 217 printf("Error: zImage kernel too big! (size: %ld, max: %d)\n", 218 kernel_size, ZIMAGE_MAX_SIZE); 219 return 0; 220 } 221 222 /* build command line at COMMAND_LINE_OFFSET */ 223 build_command_line(setup_base + COMMAND_LINE_OFFSET, auto_boot); 224 225 printf("Loading %czImage at address 0x%08x (%ld bytes)\n", big_image ? 'b' : ' ', 226 (u32)load_address, kernel_size); 227 228 229 memmove(load_address, image + setup_size, kernel_size); 230 231 /* ready for booting */ 232 return setup_base; 233 } 234 235 void boot_zimage(void *setup_base) 236 { 237 struct pt_regs regs; 238 239 memset(®s, 0, sizeof(struct pt_regs)); 240 regs.xds = (u32)setup_base >> 4; 241 regs.xes = regs.xds; 242 regs.xss = regs.xds; 243 regs.esp = 0x9000; 244 regs.eflags = 0; 245 enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, ®s, ®s); 246 } 247 248 int do_zboot (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) 249 { 250 void *base_ptr; 251 void *bzImage_addr = NULL; 252 char *s; 253 ulong bzImage_size = 0; 254 255 disable_interrupts(); 256 257 /* Setup board for maximum PC/AT Compatibility */ 258 setup_pcat_compatibility(); 259 260 if (argc >= 2) 261 /* argv[1] holds the address of the bzImage */ 262 s = argv[1]; 263 else 264 s = getenv("fileaddr"); 265 266 if (s) 267 bzImage_addr = (void *)simple_strtoul(s, NULL, 16); 268 269 if (argc >= 3) 270 /* argv[2] holds the size of the bzImage */ 271 bzImage_size = simple_strtoul(argv[2], NULL, 16); 272 273 /* Lets look for*/ 274 base_ptr = load_zimage (bzImage_addr, bzImage_size, 0, 0, 0); 275 276 if (NULL == base_ptr) { 277 printf ("## Kernel loading failed ...\n"); 278 } else { 279 printf ("## Transferring control to Linux (at address %08x) ...\n", 280 (u32)base_ptr); 281 282 /* we assume that the kernel is in place */ 283 printf("\nStarting kernel ...\n\n"); 284 285 boot_zimage(base_ptr); 286 /* does not return */ 287 } 288 289 return -1; 290 } 291 292 U_BOOT_CMD( 293 zboot, 2, 0, do_zboot, 294 "Boot bzImage", 295 "" 296 ); 297