CloverBootloader/ArmPkg/Library/ArmHvcLib/Arm/ArmHvc.S

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//
// Copyright (c) 2012-2014, ARM Limited. All rights reserved.
// Copyright (c) 2014-2016, Linaro Limited. All rights reserved.
//
// SPDX-License-Identifier: BSD-2-Clause-Patent
//
//
#include <AsmMacroIoLib.h>
.arch_extension virt
ASM_FUNC(ArmCallHvc)
push {r4-r8}
// r0 will be popped just after the HVC call
push {r0}
// Load the HVC arguments values into the appropriate registers
ldr r7, [r0, #28]
ldr r6, [r0, #24]
ldr r5, [r0, #20]
ldr r4, [r0, #16]
ldr r3, [r0, #12]
ldr r2, [r0, #8]
ldr r1, [r0, #4]
ldr r0, [r0, #0]
hvc #0
// Pop the ARM_HVC_ARGS structure address from the stack into r8
pop {r8}
// Load the HVC returned values into the appropriate registers
// A HVC call can return up to 4 values - we do not need to store back r4-r7.
str r3, [r8, #12]
str r2, [r8, #8]
str r1, [r8, #4]
str r0, [r8, #0]
mov r0, r8
// Restore the registers r4-r8
pop {r4-r8}
bx lr