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>
40 lines
1.1 KiB
ArmAsm
40 lines
1.1 KiB
ArmAsm
//
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// Copyright (c) 2016 - 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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// r0 will be popped just after the SVC call
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push {r0, r4-r8}
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// Load the SVC arguments values into the appropriate registers
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ldm r0, {r0-r7}
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svc #0
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// Load the ARM_SVC_ARGS structure address from the stack into r8
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ldr r8, [sp]
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// Load the SVC returned values into the appropriate registers
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// A SVC call can return up to 4 values - we do not need to store back r4-r7.
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stm r8, {r0-r3}
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mov r0, r8
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// Restore the registers r4-r8
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pop {r1, r4-r8}
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bx lr
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