You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
80 lines
2.7 KiB
80 lines
2.7 KiB
/*
|
|
* Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
|
|
*
|
|
* SPDX-License-Identifier: BSD-3-Clause
|
|
*/
|
|
|
|
#include <asm_macros.S>
|
|
#include "tlkd_private.h"
|
|
|
|
.global tlkd_enter_sp
|
|
.global tlkd_exit_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 tlkd_enter_sp
|
|
/* Make space for the registers that we're going to save */
|
|
mov x3, sp
|
|
str x3, [x0, #0]
|
|
sub sp, sp, #TLKD_C_RT_CTX_SIZE
|
|
|
|
/* Save callee-saved registers on to the stack */
|
|
stp x19, x20, [sp, #TLKD_C_RT_CTX_X19]
|
|
stp x21, x22, [sp, #TLKD_C_RT_CTX_X21]
|
|
stp x23, x24, [sp, #TLKD_C_RT_CTX_X23]
|
|
stp x25, x26, [sp, #TLKD_C_RT_CTX_X25]
|
|
stp x27, x28, [sp, #TLKD_C_RT_CTX_X27]
|
|
stp x29, x30, [sp, #TLKD_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 the secure payload.
|
|
* ----------------------------------------------
|
|
*/
|
|
b el3_exit
|
|
endfunc tlkd_enter_sp
|
|
|
|
/* ----------------------------------------------
|
|
* This function is called with 'x0' pointing to
|
|
* a C runtime context saved in tlkd_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
|
|
* ----------------------------------------------
|
|
*/
|
|
func tlkd_exit_sp
|
|
/* Restore the previous stack */
|
|
mov sp, x0
|
|
|
|
/* Restore callee-saved registers on to the stack */
|
|
ldp x19, x20, [x0, #(TLKD_C_RT_CTX_X19 - TLKD_C_RT_CTX_SIZE)]
|
|
ldp x21, x22, [x0, #(TLKD_C_RT_CTX_X21 - TLKD_C_RT_CTX_SIZE)]
|
|
ldp x23, x24, [x0, #(TLKD_C_RT_CTX_X23 - TLKD_C_RT_CTX_SIZE)]
|
|
ldp x25, x26, [x0, #(TLKD_C_RT_CTX_X25 - TLKD_C_RT_CTX_SIZE)]
|
|
ldp x27, x28, [x0, #(TLKD_C_RT_CTX_X27 - TLKD_C_RT_CTX_SIZE)]
|
|
ldp x29, x30, [x0, #(TLKD_C_RT_CTX_X29 - TLKD_C_RT_CTX_SIZE)]
|
|
|
|
/* ------------------------------------------------
|
|
* This should take us back to the instruction
|
|
* after the call to the last tlkd_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
|
|
endfunc tlkd_exit_sp
|
|
|