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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
|
|
