/*
* Copyright (c) 2005 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
*/
/** @addtogroup kernel_ia32
* @{
*/
/** @file
*/
#include <userspace.h>
#include <arch/pm.h>
#include <stdbool.h>
#include <stdint.h>
#include <arch.h>
#include <abi/proc/uarg.h>
#include <mm/as.h>
#include <arch/cpu.h>
#include <arch/asm.h>
/** Enter userspace
*
* Change CPU protection level to 3, enter userspace.
*
*/
void userspace(uspace_arg_t *kernel_uarg)
{
uint32_t eflags = read_eflags();
asm volatile (
/* Set up GS register (virtual register segment) */
"movl %[vreg_des], %%gs\n"
"pushl %[udata_des]\n"
"pushl %[stack_top]\n"
"pushl %[eflags]\n"
"pushl %[utext_des]\n"
"pushl %[entry]\n"
"movl %[uarg], %%eax\n"
/* %edi is defined to hold pcb_ptr - set it to 0 */
"xorl %%edi, %%edi\n"
"iret\n"
:
: [eflags_mask] "i" (~EFLAGS_NT),
[udata_des] "i" (GDT_SELECTOR(UDATA_DES) | PL_USER),
[stack_top] "r" (kernel_uarg->uspace_stack +
kernel_uarg->uspace_stack_size),
[eflags] "r" ((eflags & ~(EFLAGS_NT)) | EFLAGS_IF),
[utext_des] "i" (GDT_SELECTOR(UTEXT_DES) | PL_USER),
[entry] "r" (kernel_uarg->uspace_entry),
[uarg] "r" (kernel_uarg->uspace_uarg),
[vreg_des] "r" (GDT_SELECTOR(VREG_DES))
: "eax");
unreachable();
}
/** @}
*/