/* * 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 ia32 * @{ */ /** @file */ #include #include #include #include #include #include /** Enter userspace * * Change CPU protection level to 3, enter userspace. * */ void userspace(uspace_arg_t *kernel_uarg) { ipl_t ipl = interrupts_disable(); asm volatile ( /* * Clear nested task flag. */ "pushfl\n" "pop %%eax\n" "and $0xffffbfff, %%eax\n" "push %%eax\n" "popfl\n" /* Set up GS register (TLS) */ "movl %[tls_des], %%gs\n" "pushl %[udata_des]\n" "pushl %[stack_size]\n" "pushl %[ipl]\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" : : [udata_des] "i" (GDT_SELECTOR(UDATA_DES) | PL_USER), [stack_size] "r" ((uint8_t *) kernel_uarg->uspace_stack + THREAD_STACK_SIZE), [ipl] "r" (ipl), [utext_des] "i" (GDT_SELECTOR(UTEXT_DES) | PL_USER), [entry] "r" (kernel_uarg->uspace_entry), [uarg] "r" (kernel_uarg->uspace_uarg), [tls_des] "r" (GDT_SELECTOR(TLS_DES)) : "eax"); /* Unreachable */ while (1); } /** @} */