2 * Copyright (c) 2011 The Chromium OS Authors.
4 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
6 * See file CREDITS for list of people who contributed to this
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
26 * Linux x86 zImage and bzImage loading
28 * based on the procdure described in
29 * linux/Documentation/i386/boot.txt
34 #include <asm/ptrace.h>
35 #include <asm/zimage.h>
36 #include <asm/realmode.h>
37 #include <asm/byteorder.h>
38 #include <asm/bootparam.h>
43 * relative to setup_base (which is 0x90000 currently)
45 * 0x0000-0x7FFF Real mode kernel
46 * 0x8000-0x8FFF Stack and heap
47 * 0x9000-0x90FF Kernel command line
49 #define DEFAULT_SETUP_BASE 0x90000
50 #define COMMAND_LINE_OFFSET 0x9000
51 #define HEAP_END_OFFSET 0x8e00
53 #define COMMAND_LINE_SIZE 2048
55 unsigned generic_install_e820_map(unsigned max_entries,
56 struct e820entry *entries)
61 unsigned install_e820_map(unsigned max_entries,
62 struct e820entry *entries)
63 __attribute__((weak, alias("generic_install_e820_map")));
65 static void build_command_line(char *command_line, int auto_boot)
67 char *env_command_line;
69 command_line[0] = '\0';
71 env_command_line = getenv("bootargs");
73 /* set console= argument if we use a serial console */
74 if (!strstr(env_command_line, "console=")) {
75 if (!strcmp(getenv("stdout"), "serial")) {
77 /* We seem to use serial console */
78 sprintf(command_line, "console=ttyS0,%s ",
84 strcat(command_line, "auto ");
87 strcat(command_line, env_command_line);
89 printf("Kernel command line: \"%s\"\n", command_line);
92 void *load_zimage(char *image, unsigned long kernel_size,
93 unsigned long initrd_addr, unsigned long initrd_size,
94 int auto_boot, void **load_address)
96 struct boot_params *setup_base;
101 struct boot_params *params = (struct boot_params *)image;
102 struct setup_header *hdr = ¶ms->hdr;
104 /* base address for real-mode segment */
105 setup_base = (struct boot_params *)DEFAULT_SETUP_BASE;
107 if (KERNEL_MAGIC != hdr->boot_flag) {
108 printf("Error: Invalid Boot Flag "
109 "(found 0x%04x, expected 0x%04x)\n",
110 hdr->boot_flag, KERNEL_MAGIC);
113 printf("Valid Boot Flag\n");
116 /* determine boot protocol version */
117 if (KERNEL_V2_MAGIC == hdr->header) {
118 printf("Magic signature found\n");
120 bootproto = hdr->version;
122 /* Very old kernel */
123 printf("Magic signature not found\n");
127 /* determine size of setup */
128 if (0 == hdr->setup_sects) {
129 printf("Setup Sectors = 0 (defaulting to 4)\n");
130 setup_size = 5 * 512;
132 setup_size = (hdr->setup_sects + 1) * 512;
135 printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);
137 if (setup_size > SETUP_MAX_SIZE)
138 printf("Error: Setup is too large (%d bytes)\n", setup_size);
140 /* Determine image type */
141 big_image = (bootproto >= 0x0200) &&
142 (hdr->loadflags & BIG_KERNEL_FLAG);
144 /* Determine load address */
146 *load_address = (void *)BZIMAGE_LOAD_ADDR;
148 *load_address = (void *)ZIMAGE_LOAD_ADDR;
150 #if defined CONFIG_ZBOOT_32
151 printf("Building boot_params at 0x%8.8lx\n", (ulong)setup_base);
152 memset(setup_base, 0, sizeof(*setup_base));
153 setup_base->hdr = params->hdr;
155 setup_base->e820_entries = install_e820_map(
156 ARRAY_SIZE(setup_base->e820_map), setup_base->e820_map);
159 printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n",
160 (ulong)setup_base, setup_size);
161 memmove(setup_base, image, setup_size);
164 printf("Using boot protocol version %x.%02x\n",
165 (bootproto & 0xff00) >> 8, bootproto & 0xff);
167 if (bootproto == 0x0100) {
168 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
169 setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET;
172 * A very old kernel MUST have its real-mode code
175 if ((u32)setup_base != 0x90000) {
176 /* Copy the real-mode kernel */
177 memmove((void *)0x90000, setup_base, setup_size);
179 /* Copy the command line */
180 memmove((void *)0x99000,
181 (u8 *)setup_base + COMMAND_LINE_OFFSET,
185 setup_base = (struct boot_params *)0x90000;
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);
193 /* We are now setting up the real-mode version of the header */
194 hdr = &setup_base->hdr;
196 if (bootproto >= 0x0200) {
197 hdr->type_of_loader = 8;
199 if (hdr->setup_sects >= 15) {
200 printf("Linux kernel version %s\n",
202 hdr->kernel_version + 0x200);
204 printf("Setup Sectors < 15 - "
205 "Cannot print kernel version.\n");
209 printf("Initial RAM disk at linear address "
210 "0x%08lx, size %ld bytes\n",
211 initrd_addr, initrd_size);
213 hdr->ramdisk_image = initrd_addr;
214 hdr->ramdisk_size = initrd_size;
218 if (bootproto >= 0x0201) {
219 hdr->heap_end_ptr = HEAP_END_OFFSET;
220 hdr->loadflags |= HEAP_FLAG;
223 if (bootproto >= 0x0202) {
225 (uintptr_t)setup_base + COMMAND_LINE_OFFSET;
226 } else if (bootproto >= 0x0200) {
227 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
228 setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET;
230 hdr->setup_move_size = 0x9100;
233 if (bootproto >= 0x0204)
234 kernel_size = hdr->syssize * 16;
236 kernel_size -= setup_size;
240 if ((kernel_size) > BZIMAGE_MAX_SIZE) {
241 printf("Error: bzImage kernel too big! "
242 "(size: %ld, max: %d)\n",
243 kernel_size, BZIMAGE_MAX_SIZE);
246 } else if ((kernel_size) > ZIMAGE_MAX_SIZE) {
247 printf("Error: zImage kernel too big! (size: %ld, max: %d)\n",
248 kernel_size, ZIMAGE_MAX_SIZE);
252 /* build command line at COMMAND_LINE_OFFSET */
253 build_command_line((char *)setup_base + COMMAND_LINE_OFFSET, auto_boot);
255 printf("Loading %czImage at address 0x%08x (%ld bytes)\n",
256 big_image ? 'b' : ' ', (u32)*load_address, kernel_size);
258 memmove(*load_address, image + setup_size, kernel_size);
260 /* ready for booting */
264 void boot_zimage(void *setup_base, void *load_address)
266 printf("\nStarting kernel ...\n\n");
268 #if defined CONFIG_ZBOOT_32
270 * Set %ebx, %ebp, and %edi to 0, %esi to point to the boot_params
271 * structure, and then jump to the kernel. We assume that %cs is
272 * 0x10, 4GB flat, and read/execute, and the data segments are 0x18,
273 * 4GB flat, and read/write. U-boot is setting them up that way for
274 * itself in arch/i386/cpu/cpu.c.
276 __asm__ __volatile__ (
279 "jmp %[kernel_entry] \n"
280 :: [kernel_entry]"a"(load_address),
281 [boot_params] "S"(setup_base),
288 memset(®s, 0, sizeof(struct pt_regs));
289 regs.xds = (u32)setup_base >> 4;
294 enter_realmode(((u32)setup_base + SETUP_START_OFFSET) >> 4, 0,
299 int do_zboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
302 void *bzImage_addr = NULL;
305 ulong bzImage_size = 0;
307 disable_interrupts();
309 /* Setup board for maximum PC/AT Compatibility */
310 setup_pcat_compatibility();
313 /* argv[1] holds the address of the bzImage */
316 s = getenv("fileaddr");
320 bzImage_addr = (void *)simple_strtoul(s, NULL, 16);
323 /* argv[2] holds the size of the bzImage */
324 bzImage_size = simple_strtoul(argv[2], NULL, 16);
327 base_ptr = load_zimage(bzImage_addr, bzImage_size, 0, 0, 0,
331 printf("## Kernel loading failed ...\n");
333 printf("## Transferring control to Linux "
334 "(at address %08x) ...\n",
337 /* we assume that the kernel is in place */
338 boot_zimage(base_ptr, load_address);
339 /* does not return */
346 zboot, 2, 0, do_zboot,