summaryrefslogtreecommitdiff
path: root/lib_i386/zimage.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib_i386/zimage.c')
-rw-r--r--lib_i386/zimage.c276
1 files changed, 276 insertions, 0 deletions
diff --git a/lib_i386/zimage.c b/lib_i386/zimage.c
new file mode 100644
index 0000000..190d46e
--- /dev/null
+++ b/lib_i386/zimage.c
@@ -0,0 +1,276 @@
+/*
+ * (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(&regs, 0, sizeof(struct pt_regs));
+ regs.xds = (u32)setup_base >> 4;
+ regs.xss = 0x8e00;
+ regs.esp = 0x200;
+ regs.eflags = 0;
+ enter_realmode(((u32)setup_base+SETUP_START_OFFSET)>>4, 0, &regs, &regs);
+}
+
+
+image_header_t *fake_zimage_header(image_header_t *hdr, void *ptr, int size)
+{
+ /* There is no way to know the size of a zImage ... *
+ * so we assume that 2MB will be enough for now */
+#define ZIMAGE_SIZE 0x200000
+
+ /* load a 1MB, the loaded will have to be moved to its final
+ * position again later... */
+#define ZIMAGE_LOAD 0x100000
+
+ ulong checksum;
+
+ if (KERNEL_MAGIC != *(u16*)(ptr + BOOT_FLAG_OFF)) {
+ /* not a zImage or bzImage */
+ return NULL;
+ }
+
+ if (-1 == size) {
+ size = ZIMAGE_SIZE;
+ }
+#if 0
+ checksum = crc32 (0, ptr, size);
+#else
+ checksum = 0;
+#endif
+ memset(hdr, 0, sizeof(image_header_t));
+
+ /* Build new header */
+ hdr->ih_magic = htonl(IH_MAGIC);
+ hdr->ih_time = 0;
+ hdr->ih_size = htonl(size);
+ hdr->ih_load = htonl(ZIMAGE_LOAD);
+ hdr->ih_ep = 0;
+ hdr->ih_dcrc = htonl(checksum);
+ hdr->ih_os = IH_OS_LINUX;
+ hdr->ih_arch = IH_CPU_I386;
+ hdr->ih_type = IH_TYPE_KERNEL;
+ hdr->ih_comp = IH_COMP_NONE;
+
+ strncpy((char *)hdr->ih_name, "(none)", IH_NMLEN);
+
+ checksum = crc32(0,(const char *)hdr,sizeof(image_header_t));
+
+ hdr->ih_hcrc = htonl(checksum);
+
+ return hdr;
+}
generated by cgit v1.1 at 2024-11-21 16:55:47 +0000