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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
//
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// Copyright (c) 2012 - 2017, ARM Limited. All rights reserved.
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//
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// This program and the accompanying materials
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// are licensed and made available under the terms and conditions of the BSD License
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// which accompanies this distribution. The full text of the license may be found at
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// http://opensource.org/licenses/bsd-license.php
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//
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// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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//
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//
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.text
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.align 3
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GCC_ASM_EXPORT(ArmCallSvc)
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ASM_PFX(ArmCallSvc):
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// Push frame pointer and return address on the stack
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stp x29, x30, [sp, #-32]!
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mov x29, sp
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// Push x0 on the stack - The stack must always be quad-word aligned
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str x0, [sp, #16]
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// Load the SVC arguments values into the appropriate registers
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ldp x6, x7, [x0, #48]
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ldp x4, x5, [x0, #32]
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ldp x2, x3, [x0, #16]
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ldp x0, x1, [x0, #0]
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svc #0
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// Pop the ARM_SVC_ARGS structure address from the stack into x9
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ldr x9, [sp, #16]
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// Store the SVC returned values into the ARM_SVC_ARGS structure.
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// A SVC call can return up to 4 values - we do not need to store back x4-x7.
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stp x0, x1, [x9, #0]
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stp x2, x3, [x9, #16]
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mov x0, x9
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ldp x29, x30, [sp], #32
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ret
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