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/*
* Mach Operating System
* Copyright (c) 1991,1990 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.
*/
/*
* "Local" descriptor table. At the moment, all tasks use the
* same LDT.
*/
#include <mach/machine/vm_types.h>
#include "vm_param.h"
#include "seg.h"
#include "gdt.h"
#include "ldt.h"
extern int syscall();
struct real_descriptor ldt[LDTSZ];
void
ldt_init()
{
/* Initialize the master LDT descriptor in the GDT. */
fill_gdt_descriptor(KERNEL_LDT,
kvtolin(&ldt), sizeof(ldt)-1,
ACC_PL_K|ACC_LDT, 0);
/* Initialize the LDT descriptors. */
fill_ldt_gate(USER_SCALL,
(vm_offset_t)&syscall, KERNEL_CS,
ACC_PL_U|ACC_CALL_GATE, 0);
fill_ldt_descriptor(USER_CS,
VM_MIN_ADDRESS,
VM_MAX_ADDRESS-VM_MIN_ADDRESS-4096,
/* XXX LINEAR_... */
ACC_PL_U|ACC_CODE_R, SZ_32);
fill_ldt_descriptor(USER_DS,
VM_MIN_ADDRESS,
VM_MAX_ADDRESS-VM_MIN_ADDRESS-4096,
ACC_PL_U|ACC_DATA_W, SZ_32);
/* Activate the LDT. */
lldt(KERNEL_LDT);
}
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