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//
// Copyright (c) 2012 - 2020, ARM Limited. All rights reserved.
//
// SPDX-License-Identifier: BSD-2-Clause-Patent
//
//
.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
// Prevent speculative execution beyond svc instruction
dsb nsh
isb
// 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 8 values
stp x0, x1, [x9, #0]
stp x2, x3, [x9, #16]
stp x4, x5, [x9, #32]
stp x6, x7, [x9, #48]
mov x0, x9
ldp x29, x30, [sp], #32
ret
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