/* linux.c - boot Linux */ /* * GRUB -- GRand Unified Bootloader * Copyright (C) 2003, 2004, 2005, 2007 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 . */ #include #include #include #include #include #include #include #include #include #define ELF32_LOADMASK (0xc0000000UL) #define ELF64_LOADMASK (0xc000000000000000ULL) static grub_dl_t my_mod; static int loaded; static grub_addr_t initrd_addr; static grub_size_t initrd_size; static grub_addr_t linux_addr; static grub_size_t linux_size; static char *linux_args; typedef void (*kernel_entry_t) (void *, unsigned long, int (void *), unsigned long, unsigned long); static grub_err_t grub_linux_boot (void) { kernel_entry_t linuxmain; grub_ssize_t actual; /* Set the command line arguments. */ grub_ieee1275_set_property (grub_ieee1275_chosen, "bootargs", linux_args, grub_strlen (linux_args) + 1, &actual); grub_dprintf ("loader", "Entry point: 0x%x\n", linux_addr); grub_dprintf ("loader", "Initrd at: 0x%x, size 0x%x\n", initrd_addr, initrd_size); grub_dprintf ("loader", "Boot arguments: %s\n", linux_args); grub_dprintf ("loader", "Jumping to Linux...\n"); /* Boot the kernel. */ linuxmain = (kernel_entry_t) linux_addr; linuxmain ((void *) initrd_addr, initrd_size, grub_ieee1275_entry_fn, 0, 0); return GRUB_ERR_NONE; } static grub_err_t grub_linux_release_mem (void) { grub_free (linux_args); linux_args = 0; if (linux_addr && grub_ieee1275_release (linux_addr, linux_size)) return grub_error (GRUB_ERR_OUT_OF_MEMORY, "Can not release memory"); if (initrd_addr && grub_ieee1275_release (initrd_addr, initrd_size)) return grub_error (GRUB_ERR_OUT_OF_MEMORY, "Can not release memory"); linux_addr = 0; initrd_addr = 0; return GRUB_ERR_NONE; } static grub_err_t grub_linux_unload (void) { grub_err_t err; err = grub_linux_release_mem (); grub_dl_unref (my_mod); loaded = 0; return err; } static grub_err_t grub_linux_load32 (grub_elf_t elf) { Elf32_Addr entry; int found_addr = 0; /* Linux's entry point incorrectly contains a virtual address. */ entry = elf->ehdr.ehdr32.e_entry & ~ELF32_LOADMASK; if (entry == 0) entry = 0x01400000; linux_size = grub_elf32_size (elf, 0); if (linux_size == 0) return grub_errno; /* Pad it; the kernel scribbles over memory beyond its load address. */ linux_size += 0x100000; /* On some systems, firmware occupies the memory we're trying to use. * Happily, Linux can be loaded anywhere (it relocates itself). Iterate * until we find an open area. */ for (linux_addr = entry; linux_addr < entry + 200 * 0x100000; linux_addr += 0x100000) { grub_dprintf ("loader", "Attempting to claim at 0x%x, size 0x%x.\n", linux_addr, linux_size); found_addr = grub_claimmap (linux_addr, linux_size); if (found_addr != -1) break; } if (found_addr == -1) return grub_error (GRUB_ERR_OUT_OF_MEMORY, "Could not claim memory."); /* Now load the segments into the area we claimed. */ auto grub_err_t offset_phdr (Elf32_Phdr *phdr, grub_addr_t *addr, int *do_load); grub_err_t offset_phdr (Elf32_Phdr *phdr, grub_addr_t *addr, int *do_load) { if (phdr->p_type != PT_LOAD) { *do_load = 0; return 0; } *do_load = 1; /* Linux's program headers incorrectly contain virtual addresses. * Translate those to physical, and offset to the area we claimed. */ *addr = (phdr->p_paddr & ~ELF32_LOADMASK) + linux_addr; return 0; } return grub_elf32_load (elf, offset_phdr, 0, 0); } static grub_err_t grub_linux_load64 (grub_elf_t elf) { Elf64_Addr entry; int found_addr = 0; /* Linux's entry point incorrectly contains a virtual address. */ entry = elf->ehdr.ehdr64.e_entry & ~ELF64_LOADMASK; if (entry == 0) entry = 0x01400000; linux_size = grub_elf64_size (elf, 0); if (linux_size == 0) return grub_errno; /* Pad it; the kernel scribbles over memory beyond its load address. */ linux_size += 0x100000; /* On some systems, firmware occupies the memory we're trying to use. * Happily, Linux can be loaded anywhere (it relocates itself). Iterate * until we find an open area. */ for (linux_addr = entry; linux_addr < entry + 200 * 0x100000; linux_addr += 0x100000) { grub_dprintf ("loader", "Attempting to claim at 0x%x, size 0x%x.\n", linux_addr, linux_size); found_addr = grub_claimmap (linux_addr, linux_size); if (found_addr != -1) break; } if (found_addr == -1) return grub_error (GRUB_ERR_OUT_OF_MEMORY, "Could not claim memory."); /* Now load the segments into the area we claimed. */ auto grub_err_t offset_phdr (Elf64_Phdr *phdr, grub_addr_t *addr, int *do_load); grub_err_t offset_phdr (Elf64_Phdr *phdr, grub_addr_t *addr, int *do_load) { if (phdr->p_type != PT_LOAD) { *do_load = 0; return 0; } *do_load = 1; /* Linux's program headers incorrectly contain virtual addresses. * Translate those to physical, and offset to the area we claimed. */ *addr = (phdr->p_paddr & ~ELF64_LOADMASK) + linux_addr; return 0; } return grub_elf64_load (elf, offset_phdr, 0, 0); } static grub_err_t grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)), int argc, char *argv[]) { grub_elf_t elf = 0; int i; int size; char *dest; grub_dl_ref (my_mod); if (argc == 0) { grub_error (GRUB_ERR_BAD_ARGUMENT, "no kernel specified"); goto out; } elf = grub_elf_open (argv[0]); if (! elf) goto out; if (elf->ehdr.ehdr32.e_type != ET_EXEC) { grub_error (GRUB_ERR_UNKNOWN_OS, "This ELF file is not of the right type\n"); goto out; } /* Release the previously used memory. */ grub_loader_unset (); if (grub_elf_is_elf32 (elf)) grub_linux_load32 (elf); else if (grub_elf_is_elf64 (elf)) grub_linux_load64 (elf); else { grub_error (GRUB_ERR_BAD_FILE_TYPE, "Unknown ELF class"); goto out; } size = sizeof ("BOOT_IMAGE=") + grub_strlen (argv[0]); for (i = 0; i < argc; i++) size += grub_strlen (argv[i]) + 1; linux_args = grub_malloc (size); if (! linux_args) goto out; /* Specify the boot file. */ dest = grub_stpcpy (linux_args, "BOOT_IMAGE="); dest = grub_stpcpy (dest, argv[0]); for (i = 1; i < argc; i++) { *dest++ = ' '; dest = grub_stpcpy (dest, argv[i]); } out: if (elf) grub_elf_close (elf); if (grub_errno != GRUB_ERR_NONE) { grub_linux_release_mem (); grub_dl_unref (my_mod); loaded = 0; } else { grub_loader_set (grub_linux_boot, grub_linux_unload, 1); initrd_addr = 0; loaded = 1; } return grub_errno; } static grub_err_t grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), int argc, char *argv[]) { grub_file_t file = 0; grub_ssize_t size; grub_addr_t first_addr; grub_addr_t addr; int found_addr = 0; if (argc == 0) { grub_error (GRUB_ERR_BAD_ARGUMENT, "no initrd specified"); goto fail; } if (!loaded) { grub_error (GRUB_ERR_BAD_ARGUMENT, "You need to load the kernel first."); goto fail; } file = grub_file_open (argv[0]); if (! file) goto fail; first_addr = linux_addr + linux_size; size = grub_file_size (file); /* Attempt to claim at a series of addresses until successful in the same way that grub_rescue_cmd_linux does. */ for (addr = first_addr; addr < first_addr + 200 * 0x100000; addr += 0x100000) { grub_dprintf ("loader", "Attempting to claim at 0x%x, size 0x%x.\n", addr, size); found_addr = grub_claimmap (addr, size); if (found_addr != -1) break; } if (found_addr == -1) { grub_error (GRUB_ERR_OUT_OF_MEMORY, "Can not claim memory"); goto fail; } grub_dprintf ("loader", "Loading initrd at 0x%x, size 0x%x\n", addr, size); if (grub_file_read (file, (void *) addr, size) != size) { grub_ieee1275_release (addr, size); grub_error (GRUB_ERR_FILE_READ_ERROR, "Couldn't read file"); goto fail; } initrd_addr = addr; initrd_size = size; fail: if (file) grub_file_close (file); return grub_errno; } static grub_command_t cmd_linux, cmd_initrd; GRUB_MOD_INIT(linux) { cmd_linux = grub_register_command ("linux", grub_cmd_linux, 0, "load a linux kernel"); cmd_initrd = grub_register_command ("initrd", grub_cmd_initrd, 0, "load an initrd"); my_mod = mod; } GRUB_MOD_FINI(linux) { grub_unregister_command (cmd_linux); grub_unregister_command (cmd_initrd); }