| 1 | /*
|
|---|
| 2 | * Copyright (c) 2005 Jakub Jermar
|
|---|
| 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 ia32
|
|---|
| 30 | * @{
|
|---|
| 31 | */
|
|---|
| 32 | /** @file
|
|---|
| 33 | */
|
|---|
| 34 |
|
|---|
| 35 | #include <userspace.h>
|
|---|
| 36 | #include <arch/pm.h>
|
|---|
| 37 | #include <typedefs.h>
|
|---|
| 38 | #include <arch.h>
|
|---|
| 39 | #include <abi/proc/uarg.h>
|
|---|
| 40 | #include <mm/as.h>
|
|---|
| 41 |
|
|---|
| 42 | /** Enter userspace
|
|---|
| 43 | *
|
|---|
| 44 | * Change CPU protection level to 3, enter userspace.
|
|---|
| 45 | *
|
|---|
| 46 | */
|
|---|
| 47 | void userspace(uspace_arg_t *kernel_uarg)
|
|---|
| 48 | {
|
|---|
| 49 | ipl_t ipl = interrupts_disable();
|
|---|
| 50 |
|
|---|
| 51 | asm volatile (
|
|---|
| 52 | /*
|
|---|
| 53 | * Clear nested task flag.
|
|---|
| 54 | */
|
|---|
| 55 | "pushfl\n"
|
|---|
| 56 | "pop %%eax\n"
|
|---|
| 57 | "and $0xffffbfff, %%eax\n"
|
|---|
| 58 | "push %%eax\n"
|
|---|
| 59 | "popfl\n"
|
|---|
| 60 |
|
|---|
| 61 | /* Set up GS register (virtual register segment) */
|
|---|
| 62 | "movl %[vreg_des], %%gs\n"
|
|---|
| 63 |
|
|---|
| 64 | "pushl %[udata_des]\n"
|
|---|
| 65 | "pushl %[stack_top]\n"
|
|---|
| 66 | "pushl %[ipl]\n"
|
|---|
| 67 | "pushl %[utext_des]\n"
|
|---|
| 68 | "pushl %[entry]\n"
|
|---|
| 69 | "movl %[uarg], %%eax\n"
|
|---|
| 70 |
|
|---|
| 71 | /* %edi is defined to hold pcb_ptr - set it to 0 */
|
|---|
| 72 | "xorl %%edi, %%edi\n"
|
|---|
| 73 |
|
|---|
| 74 | "iret\n"
|
|---|
| 75 | :
|
|---|
| 76 | : [udata_des] "i" (GDT_SELECTOR(UDATA_DES) | PL_USER),
|
|---|
| 77 | [stack_top] "r" ((uint8_t *) kernel_uarg->uspace_stack +
|
|---|
| 78 | kernel_uarg->uspace_stack_size),
|
|---|
| 79 | [ipl] "r" (ipl),
|
|---|
| 80 | [utext_des] "i" (GDT_SELECTOR(UTEXT_DES) | PL_USER),
|
|---|
| 81 | [entry] "r" (kernel_uarg->uspace_entry),
|
|---|
| 82 | [uarg] "r" (kernel_uarg->uspace_uarg),
|
|---|
| 83 | [vreg_des] "r" (GDT_SELECTOR(VREG_DES))
|
|---|
| 84 | : "eax");
|
|---|
| 85 |
|
|---|
| 86 | /* Unreachable */
|
|---|
| 87 | while (1);
|
|---|
| 88 | }
|
|---|
| 89 |
|
|---|
| 90 | /** @}
|
|---|
| 91 | */
|
|---|
