source: mainline/kernel/arch/amd64/src/userspace.c@ e98f1c3e

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since e98f1c3e was 811770c, checked in by Jakub Jermar <jakub@…>, 9 years ago

Avoid magic numbers and specialized functions to set/get register bits

  • Property mode set to 100644
File size: 2.5 KB
Line 
1/*
2 * Copyright (c) 2005 Ondrej Palkovsky
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup amd64
30 * @{
31 */
32/** @file
33 */
34
35#include <userspace.h>
36#include <arch/cpu.h>
37#include <arch/pm.h>
38#include <typedefs.h>
39#include <arch.h>
40#include <abi/proc/uarg.h>
41#include <mm/as.h>
42
43/** Enter userspace
44 *
45 * Change CPU protection level to 3, enter userspace.
46 *
47 */
48void userspace(uspace_arg_t *kernel_uarg)
49{
50 uint64_t rflags = read_rflags();
51
52 rflags &= ~RFLAGS_NT;
53 rflags |= RFLAGS_IF;
54
55 asm volatile (
56 "pushq %[udata_des]\n"
57 "pushq %[stack_top]\n"
58 "pushq %[rflags]\n"
59 "pushq %[utext_des]\n"
60 "pushq %[entry]\n"
61 "movq %[uarg], %%rax\n"
62
63 /* %rdi is defined to hold pcb_ptr - set it to 0 */
64 "xorq %%rdi, %%rdi\n"
65 "iretq\n"
66 :: [udata_des] "i" (GDT_SELECTOR(UDATA_DES) | PL_USER),
67 [stack_top] "r" ((uint8_t *) kernel_uarg->uspace_stack +
68 kernel_uarg->uspace_stack_size),
69 [rflags] "r" (rflags),
70 [utext_des] "i" (GDT_SELECTOR(UTEXT_DES) | PL_USER),
71 [entry] "r" (kernel_uarg->uspace_entry),
72 [uarg] "r" (kernel_uarg->uspace_uarg)
73 : "rax"
74 );
75
76 /* Unreachable */
77 while (1);
78}
79
80/** @}
81 */
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