f8f0e454e1
This patch adds a library that enables invocation of SVCs from Exception Level EL0. It will be used by the Standalone MM environment to request services from a software running in a privileged EL e.g. ARM Trusted Firmware. The library is derived directly from Arm SMC Library. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Achin Gupta <achin.gupta@arm.com> Signed-off-by: Supreeth Venkatesh <supreeth.venkatesh@arm.com> [ardb: assign frame pointer (AArch64) keep stack alignment (ARM)] Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
47 lines
1.3 KiB
ArmAsm
47 lines
1.3 KiB
ArmAsm
//
|
|
// Copyright (c) 2012 - 2017, ARM Limited. All rights reserved.
|
|
//
|
|
// This program and the accompanying materials
|
|
// are licensed and made available under the terms and conditions of the BSD License
|
|
// which accompanies this distribution. The full text of the license may be found at
|
|
// http://opensource.org/licenses/bsd-license.php
|
|
//
|
|
// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
|
|
//
|
|
//
|
|
|
|
.text
|
|
.align 3
|
|
|
|
GCC_ASM_EXPORT(ArmCallSvc)
|
|
|
|
ASM_PFX(ArmCallSvc):
|
|
// Push frame pointer and return address on the stack
|
|
stp x29, x30, [sp, #-32]!
|
|
mov x29, sp
|
|
|
|
// Push x0 on the stack - The stack must always be quad-word aligned
|
|
str x0, [sp, #16]
|
|
|
|
// Load the SVC arguments values into the appropriate registers
|
|
ldp x6, x7, [x0, #48]
|
|
ldp x4, x5, [x0, #32]
|
|
ldp x2, x3, [x0, #16]
|
|
ldp x0, x1, [x0, #0]
|
|
|
|
svc #0
|
|
|
|
// Pop the ARM_SVC_ARGS structure address from the stack into x9
|
|
ldr x9, [sp, #16]
|
|
|
|
// Store the SVC returned values into the ARM_SVC_ARGS structure.
|
|
// A SVC call can return up to 4 values - we do not need to store back x4-x7.
|
|
stp x0, x1, [x9, #0]
|
|
stp x2, x3, [x9, #16]
|
|
|
|
mov x0, x9
|
|
|
|
ldp x29, x30, [sp], #32
|
|
ret
|