Subversion Repositories HelenOS

Rev

Rev 4345 | Blame | Compare with Previous | Last modification | View Log | Download | RSS feed

  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 <arch/types.h>
  38. #include <arch.h>
  39. #include <proc/uarg.h>
  40. #include <mm/as.h>
  41.  
  42.  
  43. /** Enter userspace
  44.  *
  45.  * Change CPU protection level to 3, enter userspace.
  46.  *
  47.  */
  48. void userspace(uspace_arg_t *kernel_uarg)
  49. {
  50.     ipl_t ipl = interrupts_disable();
  51.    
  52.     asm volatile (
  53.         /*
  54.          * Clear nested task flag.
  55.          */
  56.         "pushfl\n"
  57.         "pop %%eax\n"
  58.         "and $0xffffbfff, %%eax\n"
  59.         "push %%eax\n"
  60.         "popfl\n"
  61.        
  62.         /* Set up GS register (TLS) */
  63.         "movl %[tls_des], %%gs\n"
  64.        
  65.         "pushl %[udata_des]\n"
  66.         "pushl %[stack_size]\n"
  67.         "pushl %[ipl]\n"
  68.         "pushl %[utext_des]\n"
  69.         "pushl %[entry]\n"
  70.         "movl %[uarg], %%eax\n"
  71.        
  72.         /* %ebx is defined to hold pcb_ptr - set it to 0 */
  73.         "xorl %%ebx, %%ebx\n"
  74.        
  75.         "iret\n"
  76.         :
  77.         : [udata_des] "i" (gdtselector(UDATA_DES) | PL_USER),
  78.           [stack_size] "r" ((uint8_t *) kernel_uarg->uspace_stack + THREAD_STACK_SIZE),
  79.           [ipl] "r" (ipl),
  80.           [utext_des] "i" (gdtselector(UTEXT_DES) | PL_USER),
  81.           [entry] "r" (kernel_uarg->uspace_entry),
  82.           [uarg] "r" (kernel_uarg->uspace_uarg),
  83.           [tls_des] "r" (gdtselector(TLS_DES))
  84.         : "eax");
  85.    
  86.     /* Unreachable */
  87.     while (1);
  88. }
  89.  
  90. /** @}
  91.  */
  92.