From 102b0d2daa97dae68d3eed54d8fe37a9cc38a892 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 11:13:47 +0200 Subject: Adding upstream version 2.8.0+dfsg. Signed-off-by: Daniel Baumann --- services/spd/opteed/opteed_helpers.S | 79 ++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 services/spd/opteed/opteed_helpers.S (limited to 'services/spd/opteed/opteed_helpers.S') diff --git a/services/spd/opteed/opteed_helpers.S b/services/spd/opteed/opteed_helpers.S new file mode 100644 index 0000000..075a71b --- /dev/null +++ b/services/spd/opteed/opteed_helpers.S @@ -0,0 +1,79 @@ +/* + * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include +#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 +endfunc opteed_enter_sp + + /* --------------------------------------------- + * 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 +endfunc opteed_exit_sp -- cgit v1.2.3