| /* |
| * GRUB -- GRand Unified Bootloader |
| * Copyright (C) 2013 Free Software Foundation, Inc. |
| * |
| * GRUB 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 3 of the License, or |
| * (at your option) any later version. |
| * |
| * GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <grub/xen_file.h> |
| #include <grub/i386/linux.h> |
| #include <grub/misc.h> |
| |
| #define XZ_MAGIC "\3757zXZ\0" |
| |
| grub_elf_t |
| grub_xen_file (grub_file_t file) |
| { |
| grub_elf_t elf; |
| struct linux_kernel_header lh; |
| grub_file_t off_file; |
| grub_uint32_t payload_offset, payload_length; |
| grub_uint8_t magic[6]; |
| |
| elf = grub_elf_file (file, file->name); |
| if (elf) |
| return elf; |
| grub_errno = GRUB_ERR_NONE; |
| |
| if (grub_file_seek (file, 0) == (grub_off_t) -1) |
| goto fail; |
| |
| if (grub_file_read (file, &lh, sizeof (lh)) != sizeof (lh)) |
| goto fail; |
| |
| if (lh.boot_flag != grub_cpu_to_le16_compile_time (0xaa55) |
| || lh.header != grub_cpu_to_le32_compile_time (GRUB_LINUX_MAGIC_SIGNATURE) |
| || grub_le_to_cpu16 (lh.version) < 0x0208) |
| { |
| grub_error (GRUB_ERR_BAD_OS, "version too old for xen boot"); |
| return NULL; |
| } |
| |
| payload_length = lh.payload_length; |
| payload_offset = (lh.setup_sects + 1) * 512 |
| + lh.payload_offset; |
| |
| if (payload_length < sizeof (magic)) |
| { |
| grub_error (GRUB_ERR_BAD_OS, "payload too short"); |
| return NULL; |
| } |
| |
| grub_dprintf ("xen", "found bzimage payload 0x%llx-0x%llx\n", |
| (unsigned long long) payload_offset, |
| (unsigned long long) lh.payload_length); |
| |
| grub_file_seek (file, payload_offset); |
| |
| if (grub_file_read (file, &magic, sizeof (magic)) != sizeof (magic)) |
| { |
| if (!grub_errno) |
| grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"), |
| file->name); |
| goto fail; |
| } |
| |
| /* Kernel suffixes xz payload with their uncompressed size. |
| Trim it. */ |
| if (grub_memcmp (magic, XZ_MAGIC, sizeof (XZ_MAGIC) - 1) == 0) |
| payload_length -= 4; |
| off_file = grub_file_offset_open (file, GRUB_FILE_TYPE_LINUX_KERNEL, payload_offset, |
| payload_length); |
| if (!off_file) |
| goto fail; |
| |
| elf = grub_elf_file (off_file, file->name); |
| if (elf) |
| return elf; |
| grub_file_offset_close (off_file); |
| |
| fail: |
| grub_error (GRUB_ERR_BAD_OS, "not xen image"); |
| return NULL; |
| } |
| |
| grub_err_t |
| grub_xen_get_info (grub_elf_t elf, struct grub_xen_file_info * xi) |
| { |
| grub_memset (xi, 0, sizeof (*xi)); |
| |
| if (grub_elf_is_elf64 (elf) |
| && elf->ehdr.ehdr64.e_machine |
| == grub_cpu_to_le16_compile_time (EM_X86_64) |
| && elf->ehdr.ehdr64.e_ident[EI_DATA] == ELFDATA2LSB) |
| { |
| xi->arch = GRUB_XEN_FILE_X86_64; |
| return grub_xen_get_info64 (elf, xi); |
| } |
| if (grub_elf_is_elf32 (elf) |
| && elf->ehdr.ehdr32.e_machine == grub_cpu_to_le16_compile_time (EM_386) |
| && elf->ehdr.ehdr32.e_ident[EI_DATA] == ELFDATA2LSB) |
| { |
| xi->arch = GRUB_XEN_FILE_I386; |
| return grub_xen_get_info32 (elf, xi); |
| } |
| return grub_error (GRUB_ERR_BAD_OS, "unknown ELF type"); |
| } |