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/*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, daniel@omicron.se
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*
* Linux i386 zImage and bzImage loading
*
* based on the procdure described in
* linux/Documentation/i386/boot.txt
*/
#include <common.h>
#include <asm/io.h>
#include <asm/ptrace.h>
#include <asm/zimage.h>
#include <asm/realmode.h>
#include <asm/byteorder.h>
/*
* Memory lay-out:
*
* relative to setup_base (which is 0x90000 currently)
*
* 0x0000-0x7FFF Real mode kernel
* 0x8000-0x8FFF Stack and heap
* 0x9000-0x90FF Kernel command line
*/
#define DEFAULT_SETUP_BASE 0x90000
#define COMMAND_LINE_OFFSET 0x9000
#define HEAP_END_OFFSET 0x8e00
#define COMMAND_LINE_SIZE 2048
static void build_command_line(char *command_line, int auto_boot)
{
char *env_command_line;
command_line[0] = '\0';
env_command_line = getenv("bootargs");
/* set console= argument if we use a serial console */
if (NULL == strstr(env_command_line, "console=")) {
if (0==strcmp(getenv("stdout"), "serial")) {
/* We seem to use serial console */
sprintf(command_line, "console=ttyS0,%s ",
getenv("baudrate"));
}
}
if (auto_boot) {
strcat(command_line, "auto ");
}
if (NULL != env_command_line) {
strcat(command_line, env_command_line);
}
printf("Kernel command line: \"%s\"\n", command_line);
}
void *load_zimage(char *image, unsigned long kernel_size,
unsigned long initrd_addr, unsigned long initrd_size,
int auto_boot)
{
void *setup_base;
int setup_size;
int bootproto;
int big_image;
void *load_address;
setup_base = (void*)DEFAULT_SETUP_BASE; /* base address for real-mode segment */
if (KERNEL_MAGIC != *(u16*)(image + BOOT_FLAG_OFF)) {
printf("Error: Invalid kernel magic (found 0x%04x, expected 0xaa55)\n",
*(u16*)(image + BOOT_FLAG_OFF));
return 0;
}
/* determine boot protocol version */
if (KERNEL_V2_MAGIC == *(u32*)(image+HEADER_OFF)) {
bootproto = *(u16*)(image+VERSION_OFF);
} else {
/* Very old kernel */
bootproto = 0x0100;
}
/* determine size of setup */
if (0 == *(u8*)(image + SETUP_SECTS_OFF)) {
setup_size = 5 * 512;
} else {
setup_size = (*(u8*)(image + SETUP_SECTS_OFF) + 1) * 512;
}
if (setup_size > SETUP_MAX_SIZE) {
printf("Error: Setup is too large (%d bytes)\n", setup_size);
}
/* Determine image type */
big_image = (bootproto >= 0x0200) && (*(u8*)(image + LOADFLAGS_OFF) & BIG_KERNEL_FLAG);
/* Derermine load address */
load_address = (void*)(big_image ? BZIMAGE_LOAD_ADDR:ZIMAGE_LOAD_ADDR);
/* load setup */
memmove(setup_base, image, setup_size);
printf("Using boot protocol version %x.%02x\n",
(bootproto & 0xff00) >> 8, bootproto & 0xff);
if (bootproto == 0x0100) {
*(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
*(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET;
/* A very old kernel MUST have its real-mode code
* loaded at 0x90000 */
if ((u32)setup_base != 0x90000) {
/* Copy the real-mode kernel */
memmove((void*)0x90000, setup_base, setup_size);
/* Copy the command line */
memmove((void*)0x99000, setup_base+COMMAND_LINE_OFFSET,
COMMAND_LINE_SIZE);
setup_base = (void*)0x90000; /* Relocated */
}
/* It is recommended to clear memory up to the 32K mark */
memset((void*)0x90000 + setup_size, 0, SETUP_MAX_SIZE-setup_size);
}
if (bootproto >= 0x0200) {
*(u8*)(setup_base + TYPE_OF_LOADER_OFF) = 0xff;
printf("Linux kernel version %s\n",
(char*)(setup_base + SETUP_START_OFFSET +
*(u16*)(setup_base + START_SYS_OFF + 2)));
if (initrd_addr) {
printf("Initial RAM disk at linear address 0x%08lx, size %ld bytes\n",
initrd_addr, initrd_size);
*(u32*)(setup_base + RAMDISK_IMAGE_OFF) = initrd_addr;
*(u32*)(setup_base + RAMDISK_SIZE_OFF)=initrd_size;
}
}
if (bootproto >= 0x0201) {
*(u16*)(setup_base + HEAP_END_PTR_OFF) = HEAP_END_OFFSET;
/* CAN_USE_HEAP */
*(u8*)(setup_base + LOADFLAGS_OFF) =
*(u8*)(setup_base + LOADFLAGS_OFF) | HEAP_FLAG;
}
if (bootproto >= 0x0202) {
*(u32*)(setup_base + CMD_LINE_PTR_OFF) = (u32)setup_base + COMMAND_LINE_OFFSET;
} else if (bootproto >= 0x0200) {
*(u16*)(setup_base + CMD_LINE_MAGIC_OFF) = COMMAND_LINE_MAGIC;
*(u16*)(setup_base + CMD_LINE_OFFSET_OFF) = COMMAND_LINE_OFFSET;
*(u16*)(setup_base + SETUP_MOVE_SIZE_OFF) = 0x9100;
}
if (big_image) {
if ((kernel_size - setup_size) > BZIMAGE_MAX_SIZE) {
printf("Error: bzImage kernel too big! (size: %ld, max: %d)\n",
kernel_size - setup_size, BZIMAGE_MAX_SIZE);
return 0;
}
} else if ((kernel_size - setup_size) > ZIMAGE_MAX_SIZE) {
printf("Error: zImage kernel too big! (size: %ld, max: %d)\n",
kernel_size - setup_size, ZIMAGE_MAX_SIZE);
return 0;
}
/* build command line at COMMAND_LINE_OFFSET */
build_command_line(setup_base + COMMAND_LINE_OFFSET, auto_boot);
printf("Loading %czImage at address 0x%08x (%ld bytes)\n", big_image ? 'b' : ' ',
(u32)load_address, kernel_size - setup_size);
memmove(load_address, image + setup_size, kernel_size - setup_size);
/* ready for booting */
return setup_base;
}
void boot_zimage(void *setup_base)
{
struct pt_regs regs;
memset(®s, 0, sizeof(struct pt_regs));
regs.xds = (u32)setup_base >> 4;
regs.xss = 0x9000;
regs.esp = 0x9000;
regs.eflags = 0;
enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, ®s, ®s);
}
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