diff options
Diffstat (limited to 'grub-core/loader/i386/bsd_pagetable.c')
| -rw-r--r-- | grub-core/loader/i386/bsd_pagetable.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/grub-core/loader/i386/bsd_pagetable.c b/grub-core/loader/i386/bsd_pagetable.c new file mode 100644 index 0000000..9ec5abf --- /dev/null +++ b/grub-core/loader/i386/bsd_pagetable.c @@ -0,0 +1,92 @@ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> + * Copyright (C) 2009 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/>. + */ + +/* Based on the code from FreeBSD originally distributed under the + following terms: */ + +/*- + * Copyright (c) 1998 Michael Smith <msmith@freebsd.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + + +static void +fill_bsd64_pagetable (grub_uint8_t *src, grub_addr_t target) +{ + grub_uint64_t *pt2, *pt3, *pt4; + grub_addr_t pt2t, pt3t; + int i; + +#define PG_V 0x001 +#define PG_RW 0x002 +#define PG_U 0x004 +#define PG_PS 0x080 + + pt4 = (grub_uint64_t *) src; + pt3 = (grub_uint64_t *) (src + 4096); + pt2 = (grub_uint64_t *) (src + 8192); + + pt3t = target + 4096; + pt2t = target + 8192; + + grub_memset (src, 0, 4096 * 3); + + /* + * This is kinda brutal, but every single 1GB VM memory segment points to + * the same first 1GB of physical memory. But it is how BSD expects + * it to be. + */ + for (i = 0; i < 512; i++) + { + /* Each slot of the level 4 pages points to the same level 3 page */ + pt4[i] = (grub_addr_t) pt3t; + pt4[i] |= PG_V | PG_RW | PG_U; + + /* Each slot of the level 3 pages points to the same level 2 page */ + pt3[i] = (grub_addr_t) pt2t; + pt3[i] |= PG_V | PG_RW | PG_U; + + /* The level 2 page slots are mapped with 2MB pages for 1GB. */ + pt2[i] = i * (2 * 1024 * 1024); + pt2[i] |= PG_V | PG_RW | PG_PS | PG_U; + } +} |