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Diffstat (limited to 'arch/i386/lib/zimage.c')
| -rw-r--r-- | arch/i386/lib/zimage.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/arch/i386/lib/zimage.c b/arch/i386/lib/zimage.c new file mode 100644 index 0000000..c3b4e59 --- /dev/null +++ b/arch/i386/lib/zimage.c @@ -0,0 +1,225 @@ +/* + * (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); +} |