diff options
Diffstat (limited to 'sys/i386/boot/biosboot/table.c')
| -rw-r--r-- | sys/i386/boot/biosboot/table.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/sys/i386/boot/biosboot/table.c b/sys/i386/boot/biosboot/table.c new file mode 100644 index 0000000..c26490a --- /dev/null +++ b/sys/i386/boot/biosboot/table.c @@ -0,0 +1,112 @@ +/* + * Ported to boot 386BSD by Julian Elischer (julian@tfs.com) Sept 1992 + * + * Mach Operating System + * Copyright (c) 1992, 1991 Carnegie Mellon University + * All Rights Reserved. + * + * Permission to use, copy, modify and distribute this software and its + * documentation is hereby granted, provided that both the copyright + * notice and this permission notice appear in all copies of the + * software, derivative works or modified versions, and any portions + * thereof, and that both notices appear in supporting documentation. + * + * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" + * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR + * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. + * + * Carnegie Mellon requests users of this software to return to + * + * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU + * School of Computer Science + * Carnegie Mellon University + * Pittsburgh PA 15213-3890 + * + * any improvements or extensions that they make and grant Carnegie Mellon + * the rights to redistribute these changes. + */ + +/* + * HISTORY + * $Log: table.c,v $ + * Revision 2.2 92/04/04 11:36:43 rpd + * Fix Intel Copyright as per B. Davies authorization. + * [92/04/03 rvb] + * Taken from 2.5 bootstrap. + * [92/03/30 rvb] + * + * Revision 2.2 91/04/02 14:42:22 mbj + * Add Intel copyright + * [90/02/09 rvb] + * + */ + +/* + Copyright 1988, 1989, 1990, 1991, 1992 + by Intel Corporation, Santa Clara, California. + + All Rights Reserved + +Permission to use, copy, modify, and distribute this software and +its documentation for any purpose and without fee is hereby +granted, provided that the above copyright notice appears in all +copies and that both the copyright notice and this permission notice +appear in supporting documentation, and that the name of Intel +not be used in advertising or publicity pertaining to distribution +of the software without specific, written prior permission. + +INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE +INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, +IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR +CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM +LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, +NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION +WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +*/ + +#define NGDTENT 6 +#define GDTLIMIT 48 /* NGDTENT * 8 */ + +/* Segment Descriptor + * + * 31 24 19 16 7 0 + * ------------------------------------------------------------ + * | | |B| |A| | | |1|0|E|W|A| | + * | BASE 31..24 |G|/|0|V| LIMIT |P|DPL| TYPE | BASE 23:16 | + * | | |D| |L| 19..16| | |1|1|C|R|A| | + * ------------------------------------------------------------ + * | | | + * | BASE 15..0 | LIMIT 15..0 | + * | | | + * ------------------------------------------------------------ + */ + +struct seg_desc { + unsigned short limit_15_0; + unsigned short base_15_0; + unsigned char base_23_16; + unsigned char bit_15_8; + unsigned char bit_23_16; + unsigned char base_31_24; + }; + + +struct seg_desc Gdt[NGDTENT] = { + {0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, /* 0x0 : null */ + {0xFFFF, 0x0, 0x0, 0x9F, 0xCF, 0x0}, /* 0x08 : kernel code */ + {0xFFFF, 0x0, 0x0, 0x93, 0xCF, 0x0}, /* 0x10 : kernel data */ + {0xFFFF, 0x0000, 0x9, 0x9E, 0x40, 0x0}, /* 0x18 : boot code */ + {0xFFFF, 0x0000, 0x9, 0x92, 0x40, 0x0}, /* 0x20 : boot data */ + {0xFFFF, 0x0000, 0x9, 0x9E, 0x0, 0x0} /* 0x28 : boot code, 16 bits */ + }; + + +struct pseudo_desc { + unsigned short limit; + unsigned short base_low; + unsigned short base_high; + }; + +struct pseudo_desc Gdtr = { GDTLIMIT, 0x0400, 9 }; +struct pseudo_desc Gdtr2 = { GDTLIMIT, 0xfe00, 9 }; + /* boot is loaded at 0x90000, Gdt is at boot+1024 */ |
