3 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
5 * See file CREDITS for list of people who contributed to this
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.
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.
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,
25 * Linux x86 zImage and bzImage loading
27 * based on the procdure described in
28 * linux/Documentation/i386/boot.txt
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>
42 * relative to setup_base (which is 0x90000 currently)
44 * 0x0000-0x7FFF Real mode kernel
45 * 0x8000-0x8FFF Stack and heap
46 * 0x9000-0x90FF Kernel command line
48 #define DEFAULT_SETUP_BASE 0x90000
49 #define COMMAND_LINE_OFFSET 0x9000
50 #define HEAP_END_OFFSET 0x8e00
52 #define COMMAND_LINE_SIZE 2048
54 static void build_command_line(char *command_line, int auto_boot)
56 char *env_command_line;
58 command_line[0] = '\0';
60 env_command_line = getenv("bootargs");
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")) {
66 /* We seem to use serial console */
67 sprintf(command_line, "console=ttyS0,%s ",
73 strcat(command_line, "auto ");
76 if (NULL != env_command_line) {
77 strcat(command_line, env_command_line);
81 printf("Kernel command line: \"%s\"\n", command_line);
84 void *load_zimage(char *image, unsigned long kernel_size,
85 unsigned long initrd_addr, unsigned long initrd_size,
94 struct setup_header *hdr = (struct setup_header *)(image + SETUP_SECTS_OFF);
96 setup_base = (void*)DEFAULT_SETUP_BASE; /* base address for real-mode segment */
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);
103 printf("Valid Boot Flag\n");
106 /* determine boot protocol version */
107 if (KERNEL_V2_MAGIC == hdr->header) {
108 printf("Magic signature found\n");
110 bootproto = hdr->version;
112 /* Very old kernel */
113 printf("Magic signature not found\n");
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;
122 setup_size = (hdr->setup_sects + 1) * 512;
125 printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);
127 if (setup_size > SETUP_MAX_SIZE) {
128 printf("Error: Setup is too large (%d bytes)\n", setup_size);
131 /* Determine image type */
132 big_image = (bootproto >= 0x0200) && (hdr->loadflags & BIG_KERNEL_FLAG);
134 /* Determine load address */
135 load_address = (void*)(big_image ? BZIMAGE_LOAD_ADDR : ZIMAGE_LOAD_ADDR);
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);
141 printf("Using boot protocol version %x.%02x\n",
142 (bootproto & 0xff00) >> 8, bootproto & 0xff);
144 if (bootproto == 0x0100) {
146 *(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
147 *(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET;
149 /* A very old kernel MUST have its real-mode code
150 * loaded at 0x90000 */
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,
159 setup_base = (void*)0x90000; /* Relocated */
162 /* It is recommended to clear memory up to the 32K mark */
163 memset((void*)0x90000 + setup_size, 0, SETUP_MAX_SIZE-setup_size);
166 /* We are now setting up the real-mode version of the header */
167 hdr = (struct setup_header *)(setup_base + SETUP_SECTS_OFF);
169 if (bootproto >= 0x0200) {
170 hdr->type_of_loader = 8;
172 if (hdr->setup_sects >= 15)
173 printf("Linux kernel version %s\n", (char *)
174 (setup_base + (hdr->kernel_version + 0x200)));
176 printf("Setup Sectors < 15 - Cannot print kernel version.\n");
179 printf("Initial RAM disk at linear address 0x%08lx, size %ld bytes\n",
180 initrd_addr, initrd_size);
182 hdr->ramdisk_image = initrd_addr;
183 hdr->ramdisk_size = initrd_size;
187 if (bootproto >= 0x0201) {
188 hdr->heap_end_ptr = HEAP_END_OFFSET;
189 hdr->loadflags |= HEAP_FLAG;
192 if (bootproto >= 0x0202) {
193 hdr->cmd_line_ptr = (u32)setup_base + COMMAND_LINE_OFFSET;
194 } else if (bootproto >= 0x0200) {
196 *(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
197 *(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET;
199 hdr->setup_move_size = 0x9100;
202 if (bootproto >= 0x0204)
203 kernel_size = hdr->syssize * 16;
205 kernel_size -= setup_size;
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);
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);
221 /* build command line at COMMAND_LINE_OFFSET */
222 build_command_line(setup_base + COMMAND_LINE_OFFSET, auto_boot);
224 printf("Loading %czImage at address 0x%08x (%ld bytes)\n", big_image ? 'b' : ' ',
225 (u32)load_address, kernel_size);
228 memmove(load_address, image + setup_size, kernel_size);
230 /* ready for booting */
234 void boot_zimage(void *setup_base)
238 memset(®s, 0, sizeof(struct pt_regs));
239 regs.xds = (u32)setup_base >> 4;
244 enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, ®s, ®s);
247 int do_zboot (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
250 void *bzImage_addr = NULL;
252 ulong bzImage_size = 0;
254 disable_interrupts();
256 /* Setup board for maximum PC/AT Compatibility */
257 setup_pcat_compatibility();
260 /* argv[1] holds the address of the bzImage */
263 s = getenv("fileaddr");
266 bzImage_addr = (void *)simple_strtoul(s, NULL, 16);
269 /* argv[2] holds the size of the bzImage */
270 bzImage_size = simple_strtoul(argv[2], NULL, 16);
273 base_ptr = load_zimage (bzImage_addr, bzImage_size, 0, 0, 0);
275 if (NULL == base_ptr) {
276 printf ("## Kernel loading failed ...\n");
278 printf ("## Transferring control to Linux (at address %08x) ...\n",
281 /* we assume that the kernel is in place */
282 printf("\nStarting kernel ...\n\n");
284 boot_zimage(base_ptr);
285 /* does not return */
292 zboot, 2, 0, do_zboot,