| /* |
| * Copyright (c) 2013-2014, ARM Limited and Contributors. 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. |
| * |
| * Neither the name of ARM nor the names of its contributors may be used |
| * to endorse or promote products derived from this software without specific |
| * prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT HOLDER OR CONTRIBUTORS 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. |
| */ |
| |
| #include <asm_macros.S> |
| #include "opteed_private.h" |
| |
| .global opteed_enter_sp |
| /* --------------------------------------------- |
| * This function is called with SP_EL0 as stack. |
| * Here we stash our EL3 callee-saved registers |
| * on to the stack as a part of saving the C |
| * runtime and enter the secure payload. |
| * 'x0' contains a pointer to the memory where |
| * the address of the C runtime context is to be |
| * saved. |
| * --------------------------------------------- |
| */ |
| func opteed_enter_sp |
| /* Make space for the registers that we're going to save */ |
| mov x3, sp |
| str x3, [x0, #0] |
| sub sp, sp, #OPTEED_C_RT_CTX_SIZE |
| |
| /* Save callee-saved registers on to the stack */ |
| stp x19, x20, [sp, #OPTEED_C_RT_CTX_X19] |
| stp x21, x22, [sp, #OPTEED_C_RT_CTX_X21] |
| stp x23, x24, [sp, #OPTEED_C_RT_CTX_X23] |
| stp x25, x26, [sp, #OPTEED_C_RT_CTX_X25] |
| stp x27, x28, [sp, #OPTEED_C_RT_CTX_X27] |
| stp x29, x30, [sp, #OPTEED_C_RT_CTX_X29] |
| |
| /* --------------------------------------------- |
| * Everything is setup now. el3_exit() will |
| * use the secure context to restore to the |
| * general purpose and EL3 system registers to |
| * ERET into OPTEE. |
| * --------------------------------------------- |
| */ |
| b el3_exit |
| |
| /* --------------------------------------------- |
| * This function is called 'x0' pointing to a C |
| * runtime context saved in opteed_enter_sp(). It |
| * restores the saved registers and jumps to |
| * that runtime with 'x0' as the new sp. This |
| * destroys the C runtime context that had been |
| * built on the stack below the saved context by |
| * the caller. Later the second parameter 'x1' |
| * is passed as return value to the caller |
| * --------------------------------------------- |
| */ |
| .global opteed_exit_sp |
| func opteed_exit_sp |
| /* Restore the previous stack */ |
| mov sp, x0 |
| |
| /* Restore callee-saved registers on to the stack */ |
| ldp x19, x20, [x0, #(OPTEED_C_RT_CTX_X19 - OPTEED_C_RT_CTX_SIZE)] |
| ldp x21, x22, [x0, #(OPTEED_C_RT_CTX_X21 - OPTEED_C_RT_CTX_SIZE)] |
| ldp x23, x24, [x0, #(OPTEED_C_RT_CTX_X23 - OPTEED_C_RT_CTX_SIZE)] |
| ldp x25, x26, [x0, #(OPTEED_C_RT_CTX_X25 - OPTEED_C_RT_CTX_SIZE)] |
| ldp x27, x28, [x0, #(OPTEED_C_RT_CTX_X27 - OPTEED_C_RT_CTX_SIZE)] |
| ldp x29, x30, [x0, #(OPTEED_C_RT_CTX_X29 - OPTEED_C_RT_CTX_SIZE)] |
| |
| /* --------------------------------------------- |
| * This should take us back to the instruction |
| * after the call to the last opteed_enter_sp(). |
| * Place the second parameter to x0 so that the |
| * caller will see it as a return value from the |
| * original entry call |
| * --------------------------------------------- |
| */ |
| mov x0, x1 |
| ret |
