| 0,0 → 1,105 |
|---|
| /* |
| * Copyright (c) 2007 Petr Stepan, Pavel Jancik |
| * 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 arm32 |
| * @{ |
| */ |
| /** @file |
| * @brief Userspace switch. |
| */ |
| |
| #include <userspace.h> |
| |
| /** Struct for holding all general purpose registers. |
| * |
| * Used to set registers when going to userspace. |
| */ |
| typedef struct { |
| uint32_t r0; |
| uint32_t r1; |
| uint32_t r2; |
| uint32_t r3; |
| uint32_t r4; |
| uint32_t r5; |
| uint32_t r6; |
| uint32_t r7; |
| uint32_t r8; |
| uint32_t r9; |
| uint32_t r10; |
| uint32_t r11; |
| uint32_t r12; |
| uint32_t sp; |
| uint32_t lr; |
| uint32_t pc; |
| } ustate_t; |
| |
| /** Changes processor mode and jumps to the address specified in the first |
| * parameter. |
| * |
| * @param kernel_uarg Userspace settings (entry point, stack, ...). |
| */ |
| void userspace(uspace_arg_t *kernel_uarg) |
| { |
| volatile ustate_t ustate; |
| |
| /* set first parameter */ |
| ustate.r0 = (uintptr_t) kernel_uarg->uspace_uarg; |
| |
| /* clear other registers */ |
| ustate.r1 = ustate.r2 = ustate.r3 = ustate.r4 = ustate.r5 = |
| ustate.r6 = ustate.r7 = ustate.r8 = ustate.r9 = ustate.r10 = |
| ustate.r11 = ustate.r12 = ustate.lr = 0; |
| |
| /* set user stack */ |
| ustate.sp = ((uint32_t)kernel_uarg->uspace_stack) + PAGE_SIZE; |
| |
| /* set where uspace execution starts */ |
| ustate.pc = (uintptr_t) kernel_uarg->uspace_entry; |
| |
| /* status register in user mode */ |
| ipl_t user_mode = current_status_reg_read() & |
| (~STATUS_REG_MODE_MASK | USER_MODE); |
| |
| /* set user mode, set registers, jump */ |
| asm volatile ( |
| "mov r0, %0 \n" |
| "msr spsr_c, %1 \n" |
| "ldmfd r0!, {r0-r12, sp, lr}^ \n" |
| "ldmfd r0!, {pc}^\n" |
| : |
| : "r" (&ustate), "r" (user_mode) |
| : "r0", "r1" |
| ); |
| |
| /* unreachable */ |
| while(1) |
| ; |
| } |
| |
| /** @} |
| */ |